Dating Fender Tube Amps by Serial Number

Dating Fender Tube Amps by Serial Number

Dating Fender Tube Amps by Serial Number, Part I

by Greg Gagliano

Copyright 1997, 20th Century Guitar Magazine.

Boy, that title got your attention didn't it? Well, we'll get to good parts, but first a little background information is

in order. After reading Teagle and Sprung's excellent Fender amp book, I took them up on their challenge that

maybe someday someone will compile enough serial numbers so that Fender amps can be dated that way. So

began my quest. I contacted several Fenders collectors and dealers who were kind enough to supply me with

data.

I turned to the Internet to do some more networking which resulted in a major turn of events as I met two

individuals who have become instrumental partners in this project: Greg Huntington and Devin Riebe. Greg is a

long time Fender collector who is very knowledgeable not only in the details, but in the circuitry as well. His

particular area of expertise is in Fender amps made from about 1960 through 1967. Devin runs Doc's Music in

Springfield, Missouri and his interest lies in the woodie and tweed Fender amps made from 1946 through 1960.

Greg and Devin's experience meshed well with mine since I'm essentially the blackface/silverface amp guy (amps

made between 1963 and 1980) in the group.

Additionally, Greg and Devin also had data that they had been collecting from Fender amps for years. We

combined all of our information into a computerized database for this project and for the past 18 months have

been slowly (sadly, very slowly) gathering information that we collect ourselves as well as from other people.

Now it's time for a commercial. We need your Fender amp data! Everything is confidential, we don't make

record of who owns what amp in the database. What we need is the following:

1) Model name

2) Model number on the tube chart

3) Date code letters on the tube chart

4) Speaker codes (if speaker is original)

5) Transformer codes (if the amp doesn't have date codes on the tube chart)

6) Cosmetic features (flat/raised logo, tweed/tolex, blackface/silverface, rough/

smooth blond tolex, white/skirted knobs, TV-front/wide-panel, etc.)

One very interesting and very important factoid has surfaced regarding the date code letters on the tube chart. In

the fall of 1965, Fender switched from stamping these numbers in black ink, to dark green ink. These 1965

codes begin with the letter "O." The code for the year 1966 is "P." However, someone in the factory apparently

forgot to switch the stamper from "O" to "P" in January 1966. Therefore, amps from January 1966 have the

date code "OA" (A denotes January) in green ink. The factory realized its mistake in February because these

amps have a "PB" date code in black ink. Now, we obviously haven't looked at every amp made in January

1966 so this isn't set in stone. If anyone has an amp with a "PA" stamp, please let us know. Still, I wouldn't be

too quick to just glance at that tube chart and accept an "OA" as a January 1965 amp.

The biggest tip off would be the control panels which brings us to interesting factoid #2. After CBS bought

Fender in January 1965, there were still plenty of control panels for various models that were in stock. These

say "Fender Electric Instruments." Depending on the model the use of these pre-CBS panels have been

observed on amps as late as August 1965, except for Champs and Vibro Champs which had foil stickers on the

back the chassis. Fender must have had a million of these labels printed up since they appear on Champs and

Vibro Champs well into 1966. New panels made after the CBS acquisition were used beginning in April 1965

and say "Fender Musical Instruments." So, if you have January 1965 amp, it will have a Fender Electric

Instruments panel whereas a January 1966 amp (even though it has that green "OA" date stamp) will have

Fender Musical Instruments.

Okay, now on to the dating-by-number stuff. Although the database doesn't have thousands upon thousands of

entries, we are seeing some interesting patterns emerging that will help date amps by serial number. Some of the

trends are really obvious.

The early amps (woodie and tweed) had serial numbers handwritten on the tube chart. These appear to be used

sequentially independent of model. Likewise, the brown/blonde Tremolux, Concert, Vibrasonic, Twin, Pro,

Super, Vibrolux, Showman, Dual Showman, and Bandmaster used a sequential numbering independent of

model, but as with Fender guitars, these were not used consecutively.

Some amps had their own numbering system. The 1956 to 1963 Champ, Harvard, Princeton, Deluxe; the 1956

to 1960 Vibrolux, the 1956 to 1964 Bassman, and all the tube reverb units have their own serialization scheme.

The Champ has a "C" prefix, the Harvard an "H" prefix, the Princeton a "P" prefix, the Vibrolux a "F" prefix, and

the Deluxe a "D" prefix. The 4x10 Bassman used the prefix "BM" while the piggyback Bassman used the prefix

"BP." The reverb units have the prefix "R." In addition, the tweed Super, Pro and Bandmaster sometimes have

the prefix "S" in the serial number.

The blackface and silverface amps (late 1963 to 1980) generally have serial numbers begin with the prefix "A."

However, it appears that these were not used sequentially across all models. Our evidence is that we are finding

some serial numbers duplicated between models. For example, serial number A00121 has been found on a

Champ dated November 1964 and a Vibrolux Reverb dated February 1965. This makes things a little more

interesting and difficult in playing the "dating game." And yet there is another variable to contend with as it

appears that models that share chassis may also share the same serialization scheme. For instance, the

Bandmaster Reverb and Super Reverb share the same chassis, and the Twin Reverb, Quad Reverb, Dual

Showman Reverb, Vibrosonic Reverb, and Super Six all share the same chassis.

Preliminary results show that we're on the right track. Here's a couple of examples using the tweed Deluxe

(model 5E3) and the Super Reverb/Bandmaster Reverb.

Ser No. Model Year

D05108 Deluxe 1958

D05160 Deluxe 1958

D06528 Deluxe 1958

D07036 Deluxe 1959

D07115 Deluxe 1959

D07418 Deluxe 1959

D08325 Deluxe 1959

D08913 Deluxe 1959

D09014 Deluxe 1959

D09338 Deluxe 1960

D09399 Deluxe 1960

D09524 Deluxe 1960

A27769 Super Reverb 1967




A31079 Bandmaster Reverb 1968








So, with the knowledge gained thus far, we feel that Fender tube amps can be dated by serial number. We just

don't have enough data to make any definitive conclusions yet. We will be writing articles in the future with more

fun factoids (yes, there's more!) with new information on dating by serial number. Thanks for your support!

The author and his partners would like to thank those people who have sent us Fender amp information,

especially James Werner, Tim Pershing, Gregg Hopkins at Vintage Amp Restoration, Jim Strahm and

Matt Kesler at Midwestern Musical Co., and Tim Nelson at Mass Street Music. Also thanks to the many

dealers at the various guitar shows that we visit for allowing us to make notes about the amps at their

booths.

Dating Fender Tube Amps By Serial Number, Part 2

by Greg Gagliano


It's been about 6 months since Part 1 of this series was printed so I thought it would be a good time to give an

update on the Fender amp research that I am doing along with Devin Riebe and Greg Huntington. First I would

like to thank everyone who responded to our request for data as outlined in the initial article that was printed in

March 1997 issue of TCG. Most notably, I'd like to thank Jeff Lacio for his contributions to our research. Jeff

is an amp tech who specializes in Fender amps, i.e. only Fender amps, and single handedly has submitted well

over 250 very complete sets of data. Despite the heroic efforts by Jeff and other readers, we still need more

data, so please keep it coming.

In the meantime, we have discovered many fascinating factoids about Fender amps and we'll probably learn a lot

more as our research continues. Here are some examples of what we've found so far.

Early silver face amps: The silverface amps appear to have been introduced as early as April 1967 (yes,

April!) and by the Fall of 1967 the conversion from blackface to silverface cosmetics was completed. The early

silverface amps can be identified by the aluminum trim strip around the perimeter of the grill, the silver and blue

grill, and black vertical lines silk-screened onto the front of the control panel.

The aluminum trim was retained through late 1969, though we speculate a few early 1970 amps may have had

the grill trim as well. If anybody has a 1970 amp with trim please let us know! Two types of blue and silver

grillcloth were used on the early silverface amps. The first type (1967 - early 1968) had no silver metallic

threads and the second is the more familiar cloth with the silver metallic threads and a much greater texture or

thickness than the first type (mid-1968 onward). The black vertical lines on the control panel were discontinued

by May 1968 on most models, but we’ve seen a Bandmaster and Bassman from 1969 with them.

Interestingly, some silverface amps from early 1968 have 16 inch tilt back legs with serial numbers on one or

both legs. Tilt back legs with serial numbers were used only on the speaker cabinets of piggyback amps. One

of the legs on the cabinet would have the number while the other would simply be stamped with "Pat. Pend." In

1967, CBS Fender discontinued the small cabinet design Bassman and Bandmaster an introduced new, larger

cabs without legs. Apparently, Fender had a surplus of 16 inch Bassman/Bandmaster tilt back legs with serial

numbers on them. Rather than waste them, they were used on combo amps such as the Twin Reverb and Pro

Reverb.

Although the cosmetics changed, the circuits remained unaltered from the blackface circuits on these early

silverface amps. The date of the change from the blackface circuit to the CBS silverface circuit was dependent

on the model, but most of the amps that were modified received the circuit change by mid-year of 1968.

Another interesting feature of the silverface amps is the change in chassis dates. Many blackface amps were

stamped with a date code on the inside of the chassis. These read something like T020366 or F034267 where

the "66" and "67" denote the year and the "03" and "42" denote week of the year. This system was continued on

the silverface amps, some of which have the stamp on the underside of the chassis (where you can see it easily)

in addition to the stamp on the chassis interior. This is very useful information in the absence of a tube chart or

lack of a date code.

In the late 1970s and early 1980s, the chassis date stamp became more cryptic. For example, a chassis stamp

of 1831 must be read backward to reveal the date, in this case week 13 of 1981. If you see a chassis stamp

and you don't have any other dating info, please send it along with the serial number and model name to us,

thanks!

Mistakes: Errors happen and Fender was not immune to them. Previously we discussed the "OA" date code

stamped in dark green ink on January 1966 amps. The code should have been "PA," but the production staff

forgot to change the year on the stamper. Well, I was contacted by one Chicago reader (I'm so embarrassed I

forgot his name!) who has a February 1966 Deluxe Reverb stamped with "OB" in dark green ink (should be

"PB"). This indicates that the production team didn't catch the error until early February 1966 at which time they

switched from "O" to "P" and from dark green ink to black ink. Again, if you have an amp with an OA or OB

date code you have to look at the front and back panels to see if it says Fender Electric Instruments (in which

case the "O" denotes 1965) or Fender Musical Instruments (the "O" is a mistake and the amp is a '66).

And speaking of back panels... the back panel of our reader's Deluxe Reverb states "Division of Colombia

Records Division" instead of "Division of Columbia Records Division." Note the spelling of Columbia has an "o"

instead of a "u"!! At first this typographical error appears to have been short lived and confined to February

1966 since it hasn't been reported for any amps made in January or March 1966. However, just before this

article went to print, I found a late 1965 Deluxe Reverb with Columbia misspelled. If you have an amp with this

typographical error, please let us know and I'll report the results in Part 3 of this series!

And don't think that pre-CBS Fender was immune to mistakes... they weren't! I have seen two narrow panel

tweed Deluxes from late 1957 with a misprint on the tube chart. Instead of showing the model number as "5E3"

the tube chart was printed with "5F6." The 5F6 was the two input 4x10 Bassman, yet the tube chart is a Deluxe

tube chart. Plausible reasons for this mistake making it into production: 1) Leo Fender, being frugal, may have

use these erroneous tube charts just to save money, 2) the error wasn't noticed until a few dozen Deluxes were

made, 3) there were no other tube charts available and Fender had no choice but to use the ones with the error

until a new batch could be printed.

Another example of a mistake from the pre-CBS days is a brown '62 Concert amp that was mistakenly fitted

with the circuit board from a blonde Twin/Showman! Oops!

Hole to Nowhere: Some of you may have noticed that the very early brown tolex amps from 1960 have a hole

(sometimes plugged) on the back of the chassis labeled "Pulse Adjust." We have yet to find an amp with a

potentiometer mounted there and no schematics that we have found to date show a "pulse adjust" pot. We

speculate that Leo may have envisioned (and maybe even prototyped) a simple signal-injecting circuit whereby

he planned to inject a pulse into the amp and adjust a control to optimize the amp's response to that pulse. This

could have been a high frequency pulse and the amp's response could have been adjusted to yield the best high

frequency reproduction just short of allowing a high frequency parasitic oscillation.

Or... it could have involved injecting a high level pulse and the control was adjusted to optimize the amp's

response to obtain the best (balanced) sine wave with minimum crossover. Or... it could have involved injecting

a "square wave" and the control was adjusted to obtain the best non-ringing, non-sagging waveform. Or... it

could simply have been a bias adjustment. Despite all the theory and conjecture, Fender clearly deemed the

Pulse Adjust control to be unnecessary.

First, Last and Transitional: During our research, we do find some amps that are especially interesting

because they are one of the first, one of the last, or a transitional example of a particular model made. For

instance, we found a very early Quadreverb (s/n A38053). This model was introduced in 1972 and this

particular amp had transformers and speakers dated from late 1971, though it was probably assembled in the

very early part of 1972.

The Tremolux (AB763) and Reverb Unit (6G15) were both discontinued in 1966. In fact, Greg Huntington has

a Fender catalog dated September 16, 1966 and it does not list the Tremolux. The latest Tremolux that we have

in the database (s/n A07779) hails from September 1966 and has a production number of 71. We also have

two others from this same production batch with September 1966 tube chart dates so it looks like this was the

last month of production for the venerable Tremolux. The latest Reverb Unit that we have seen (s/n R10651) is

from May 1966 with a production number of 46. However, we aren't sure at this point if May is the last month

of production for the tube reverb unit. If you have a later example, please let us know!

An example of a transitional amp is the first batch of blackface Dual Showmans (AA763). These are very rare

and are prized more by collectors than players. The blackface Dual Showman circuit was introduced in

September 1963. The amps were covered in smooth blond tolex and had tan/gold grill cloth. The very first

batches of these amps (Prod. #2 for sure, but likely Prod. #1 as well) from September and October 1963 used

a quad of 7355 power tubes instead of 6L6GCs as the blonde Dual Showman (6G14-A) and most blackface

Dual Showman (AB763). This amp uses a completely unique output transformer (Part # 125A18A) not found

on any other amp though there is speculation and some evidence that a few of the very earliest Twin Reverbs

used 7355s since, like the Dual Showman, it was an 80 watt, 4 power tube amp with a 4 ohm output

transformer. In addition, the 1963 catalog specifically shows 7355 power tubes for the Twin, Showman and....

the Bassman and possibly the Concert!

Though we don't know why 7355s were used, perhaps Leo got a good deal from RCA on a boatload of these

tubes so he tried them out in the Dual Showman and Twin Reverb. So why did he switch back to 6L6GCs?

Probably because the 7355s aren't rated to operate at the higher voltages that the Dual Showman and Twin

Reverb could dish out. They are a smaller tube, similar to a 5881/6L6GB and hence can get hotter than a tube

with a larger envelope. By all accounts from two owners of Dual Showman with 7355s, they don't produce as

much power as a Twin Reverb or Dual Showman with 6L6GCs, though the tone is apparently acceptable.

These days 7355s aren't too easy to find either. Hence, these are reasons why players don't care about these

rarebirds very much and have converted some of them to use 6L6GCs. Debauchery!

Dating by Serial Number: Here's the part everyone has been waiting for. Yes, we are confident that we have

cracked the date codes on the reissue amps! We have some transformer date code information to support this,

too. There are two letters stamped on the tube chart on the line that says "Production." The first letter denotes

the year and the second letter denotes the month just like on the amps made in the '50s and '60s. However, the

reissue codes are as follows:

A = 1990 A = January

B = 1991 B = February

C = 1992 C = March

D = 1993 D = April

E = 1994 E = May

F = 1995 F = June

G = 1996 G = July

H = 1997 H = August

I = September

J = October

K = November

L = December

For example, reissue Bassman (s/n AA05559) with the Production Code EJ would have a production date of

October 1994.

Unfortunately, for the older amps, we still are not at the point where we can give any kind of definitive dating

scheme. To satisfy your thirst for knowledge, here's another sample from the database that shows that we are

on the right track, but that we desperately need more data sets:

A20599 Princeton Reverb 1968

A20979 Princeton Reverb























As you can see, we do get quite a bit of data without any date code info which create "holes" in the database.

This is problematic, but lately folks are feeling more comfortable finding the transformer date codes and sending

them to us with the serial number/model name for their silverface amps.

Reminder: We are still in need of information about any and all Fender tube amps. Everything is confidential, we

don't make record of who owns what amp in the database. What we need is the following information :

1) Serial Number

2) Model name



5) Speaker codes and model (if speaker is original)




So please... use the hand form mentioned above, or send your amp data to the author c/o TCG Magazine or by

e-mail to [email protected]. Thanks for your support and stay tuned for Part 3 of this series!

The author and his partners would like to thank those people who have sent us Fender amp information

(and you know who you are dahlings). Also thanks to the many dealers at the various guitar shows that

we visit for allowing us to make notes about the amps at their booths.

Dating Fender Tube Amps by Serial Number, Part 3

by Greg Gagliano


I know, I know. It’s been over a year since Part 2 of this series was printed, but that’s because I’ve been busy

collecting data. For those readers who may have joined us recently, I am doing some Fender amp research along

with Devin Riebe and Greg Huntington. Our research efforts are now in their fourth year (will it ever end?). Part

1 and Part 2 of this series can be found in the March 1997 and November 1997 issues of TCG, respectively.

Again, I would like to thank everyone who responded to our request for data as outlined in Parts 1 and 2.

The main focus of this article will be speakers found in Fender amps, but before we get into that topic let's go

over a few other areas first.

Early silver face amps: Part 2 went into this topic in some detail, but since that article was printed, I have been

asked a lot of questions about this subject. There still seems to be some confusion about how to distinguish

between a silverface Fender amp that has the desirable AB763 circuit and one that has the less-desirable

AB568/AC568 circuit. Part of the confusion stems from the lack of any AB568 or AC568 tube charts. Fender

never printed any since there were plenty of leftover AB763 tube charts available and these were used well into

1969.

Although the cosmetics changed, the circuits remained unaltered from the blackface circuits on the earliest

silverface amps. The date of the change from the blackface circuit to the CBS silverface circuit was dependent

on the model, but most of the amps that were modified received the circuit change by mid-year of 1968.

The cosmetics of the silverface amps during the transition between circuits was also in transition making it difficult

to determine circuit type on cosmetics alone. The amps during this period could have the earliest style silverface

grill cloth or the more familiar silverface grill cloth. All of the amps would have the aluminum grill trim and they

may or may not have the thin black vertical lines on the control panel. One clue that can be used is the ink

stamped chassis date code that is usually located in the chassis, but is sometimes found on the underside of the

chassis behind the tubes. These read something like T020366 or F034267 where the "66" and "67" denote the

year and the "03" and "42" denote week of the year.

Of course, the most foolproof way is to pull the chassis and look at the layout. In fact, on the 40-watt and 80-

watt amps you can simply pull the chassis out about 2 inches and look for the big honking ceramic power

resistors that are connected to ground from the cathode (pin 8) of the power tubes. If those resistors are there,

the amp has the dreaded CBS silverface circuit. I am also confident that the serial number can be used as a

rough guide for determining the circuit, but again, pulling the chassis is the only way to confirm.

Transitional circuits: I've been getting quite a few reports from amp geeks about circuits that don't completely

match the schematic for a particular model. Leo Fender was notorious for tweaking circuits and the results of

some of his tinkering can be found on late examples of an amp prior to the switch to a new circuit. Also, the

different component values could be due to a necessary substitution on the production line when a particular

value was out of stock. Ran out of 100K ohm resistors? Stick a 90K in there: no one will notice or care (at least

not until the mid to late 1990s).

These changes have been observed on tweed, brown/blonde, and blackface models. Often the differences are

minor such as small changes in resistor or capacitor values. I had a '63 Concert with the 6G12-A circuit but had

a completely different (factory stock) bias supply circuit than shown on the schematic.

Perhaps the most surprising transitional circuit that has been reported to me (thanks Brian!) is for the early 1968

silverface Showman. Two examples are known to exist; one from the February-March period and one from the

March-April period. These amps have AB763 tube charts and normally any silverface amp made prior to May

1968 will have the AB763 (a.k.a. blackface) circuit. After April 1968, most of the big Fender amps received the

AC568 circuit, which is a semi-cathode biased design. However, these two Showman amps have a fully cathode

biased design that is factory stock!!! There is also an unconfirmed report of an early '68 Twin Reverb with the

cathode bias circuit. If you see one of these cathode biased amps, please let me know!

These amps do not have a bias trim pot. The wire from the two 220K ohm bias resistors is connected to the

brass control panel ground plate. The only thing connected to the bias cap/diode is the tremolo circuit. The

cathodes are tied together and connected to a single 165-ohm resistor and 80 mfd 150V bypass capacitor which

are both grounded at the other end. This cathode set up is similar to, but simpler than, the AC568 circuit. Every

other part of the circuit (power and preamp) is identical to the blackface AB763 schematic.

Perhaps these two Showman amps were field prototypes, experimental units, transitional between the AB763

and AC563 circuit, or just a plain bad idea. Bad because cathode biased amps run very hot especially those with

four power tubes (witness the Vox AC-30). In addition, a cathode biased Showman would produce something

around 50 watts of power instead of the 80-plus watts from a fixed (grid) bias Showman. According to the

owner of one of the cathode biased amps, it runs very hot; so hot that the tolex melted under the chassis

mounting strap near the power tubes! Also, the amp eats power tubes, does not have much headroom and

breaks up early.

Oddities: One of Leo's experiments or "one off" custom amps surfaced recently. It's a circa 1955 tweed

Tremolux (5E9) that has two factory stock Jensen Hi-Frequency tweeters with a passive crossover between the

Jensen P12R and the tweeters. I wonder if Leo was influenced by Magnatone's use of tweeters?

A few export model brown/blonde amps have surfaced that have a 6-way voltage selector switch located in the

chassis, instead of on the back of the chassis. This necessitates removing the chassis from the cab to change the

voltage setting (which would only be a problem if you hopping from country to country with the amp).

Interestingly, these amps have Triad power transformers while concurrently produced domestic models had

Schumacher units.

CBS era quality control: We've previously discussed the "OA" and "OB" date codes mistakenly stamped on

the tube charts of January 1966 and February 1966 amps, respectively. As well, we've discussed misspelling

"Division of Colombia Records Division" instead of "Division of Columbia Records Division" on the rear chassis

panel on some amps from late 1965 and early 1966.

These mistakes were merely cosmetic. There were quality lapses in the circuits themselves during the CBS years,

some of which had serious consequences. Examples of these include ceramic caps used in parallel to achieve the

correct value instead of a single cap, change to often inferior sounding "chocolate drop" caps, and incorrectly

wired circuits.

A friend brought me a '66 Princeton Reverb that was humming badly. I recognized the 60 cycle hum and thought

perhaps the filter caps were shot, but it turned out the two 100-ohm ground resistors for the tube filaments were

never installed at the factory!!! I’m surprised the Fender dealer didn't send the amp back and even more

surprised that somebody bought it with the way it was humming!

I also worked on a late '67 silverface Deluxe Reverb (with the blackface circuit) with an inoperable tremolo.

Boy, was I surprised to see that the tremolo circuit was wired incorrectly by the factory!!! Either the factory

worker was asleep at the wheel that day or there was a new hire that was still learning how to assemble amplifier

circuit boards. I tend to believe that the latter idea has some merit since Fender practically doubled its size after

the CBS takeover. Bigger facilities meant more workers with little or no experience.

Speakers: Like many people, I was a bit disappointed that Teagle and Sprung's Fender amp book did not have

much info on speakers. So, I have compiled a list of speakers used in Fender amps and took some photos of

some of them as well. The list, presented below, is based on our actual observations, but is not comprehensive.

If you have a Fender amp with a factory stock speaker other than one shown here, please let us know and we'll

add it to the list!

JBL: JBL speakers were optional (at additional cost) for nearly all models from 1960 to about 1980. JBL D-

series speakers had orange baskets and Fender by JBL labels in the 1970s. JBL D-series speakers can

generally handle upwards of 60 watts each. A pair of JBL D-120Fs in a Twin Reverb are only seeing about 40-

watts each (no sweat), but remember that no speaker likes to see square waveforms. So, driving the Twin with

any amount of distortion lowers the power handling capacity of the speaker, which makes any speaker more

susceptible to damage; even a high-wattage type like the JBL.

Jensen: Jensen was the prevalent stock speaker in Fender amps from 1946 through about 1961. As the story

goes, Leo Fender wanted Jensen to make some changes to speakers and either the speaker couldn't (price

constraints?) or wouldn't do so. That's when ol' Leo switched over to Oxford as the standard speaker (though

Jensens were still used from time to time). Just conjecture, but the lack of orders from Fender from 1962 - 65

must have hurt Jensen's pocketbook so they hit up the new owners of Fender (CBS) for some business. These

Jensens wear brown and gold Fender by Jensen label and were put into Fender amps beginning in late 1965

through about mid-1967. Some amp geeks don't like the way these Fender label Jensens sound, but let your

ears be your guide. I think they sound just spiffy.

Jensen Vibranto LI and MI series speakers (alnico magnets) and Jensen EM-series speakers (ceramic magnets),

while excellent, were not used by Fender. I have included them here because I get a lot of questions about them.

They are were often sold as replacements for blown speakers which is probably one reason why the ended up in

more than a few Fenders. The Vibranto LI series speakers had a lifetime warranty and it seems that Jensen went

out of the musical instrument speaker business just in time to avoid the claims. All speakers can and will fail

eventually (just like the hard disk on your computer); remember that.

Jensen speaker models denote their approximate power handling capacity and magnet type. The actual power

ratings have been published in several books so I'll discuss them in general terms here.

The R, S, and T suffixes denote a low power rating: good for Princetons and Champs, but the R is barely able to

handle the power of a Deluxe. The Q and P suffixes denote a medium power rating. These are especially good

for multi-speaker amps up to 40-watts since multiple speakers divide the amp's total output power between

them. For this reason, the P10Q is the speaker to have in the 5F6-A Bassman. Note that it does not appear that

Fender used the "P" rated speakers very often. The N and LL suffixes denote a high power rating, with "high

power" being a relative term. The P12N, on a good day, can handle 20 watts. It's no wonder that 80-watt Twins

easily shredded a pair of them. Note that Fender did not use the "L" rated speakers (but Ampeg and Leslie did).

Oxford: Oxford speakers codes work in a similar fashion, but it is the letter that denotes power handling. The

higher the letter, the higher the power rating. I found an Oxford ad in a 1960s trade magazine with the peak

power ratings of some speakers: K = 25 watts, L = 30 watts, M = 40 watts, and T = 45 watts (12" speaker) or

60 watts (15" speaker). It is important to note that these are peak power ratings, not RMS power. The RMS

rating is more realistic and is usually about half of the peak rating so use that as a rough guide.

The "J" rated speakers are usually found on 12-watt Princetons. The "K" rated speakers are found in reverb and

non-reverb Deluxes and in multi-speaker amps up to 40-watts such as the Tremolux and Concert. The "L" rated

speakers are found in reverb and non-reverb Deluxes, some Tremolux amps, and multi-speaker amps like the

blackface Concert, Super Reverb and Vibrolux Reverb. The "M" rated speakers had good service life in the

piggyback Bassman and Bandmaster amps, but were easily blown in blonde Twins. The "T" rated speakers were

standard in Twin Reverbs, but like the Jensen C12Ns, they often had a short service life.

Many amp geeks don't like Oxford speakers found in Fender amps from 1965 through the 1970s. The gap

distance was increased in the Oxfords that Fender used later in the decade and this reduced their efficiency (and

they were cheaper to make this way). Again, I say let your ears be your guide. I've heard many great sounding

Fender amps with Oxfords. I will admit that I prefer Jensens, but I've never let an Oxford speaker sway my

decision from owning a Fender amp. Additionally, the Oxfords from early '60s generally sound very good.

According to noted vintage amp specialist Gregg Hopkins, these early Oxfords were constructed similarly to

Jensens from that period with respect to materials and voice coil gap. That could explain why they sound good.

CTS: CTS (Chicago Telephone Supply!) speakers were used occasionally in Fender amps until the mid-1960s.

These are good quality speakers that tonally lie between Jensens and Oxfords. The alnico 10-inch CTS speaker

was the most prevalent speaker in Super Reverbs from the mid-1960s through the 1970s.

Utah: Fender didn't use Utah speakers very much until the 1970s. The Utah speakers from the '50s sound very

good and I've heard a killer '66 Super Reverb that was equipped with factory original Utahs. Generally, the Utah

speakers of the '70s weren't as great sounding as their predecessors, but again let your ears be your guide. If you

like the way your '75 Twin Reverb sounds with its Utah speakers, just leave it alone and go right on playing.

Utah went on to become Pyle of Radio Shack and car audio fame.

Eminence: Eminence has its roots in CTS (Mr. Gault left CTS to found Eminence) and many of the early

Eminence designs are similar or identical to CTS speakers (good examples of the similarities can be found in

mid-1970s Ampegs). Fender began using Eminence speakers as standard in nearly all of its tube amps beginning

in the early 1980s. These are generally made to Fender's specifications and in some cases, such as the reissue

'65 Twin Reverb, the speakers were designed to emulate the Jensen C12N speakers which were often found in

the original '65 Twin.

Rola: Yet another speaker that Fender used in the mid to late 1970s was Rola.

So in technical terms, why don't the non-Jensen speakers from the mid-1960s through the 1970s sound as good

as Jensen speakers? Speaker guru Ted Weber explains:

"Utah, CTS, Oxford, etc. simply copied the Jensen designs and started competing for Fender's business. As a

result of the price wars, they had figure out how to make the speakers produceable with a very low reject rate as

well as use less expensive parts, i.e. smaller magnets. So, they widened the gaps to make them easier to throw

together on a fast assembly line. This lowered the energy, so the voice coils were shortened to compensate. The

companies also needed to produce speakers with long term reliability, so they doped the surrounds. The end

result is that with some of these speakers you get a relatively sensitive driver that sounds great at lower volumes,

but falls apart when you push it -- flabby on the low end and/or harsh on the high end."

Replacement speakers: It is very common to find non-original speakers in Fender amps made up through about

1980. Because reconing wasn't a common option until the 1970s, players simply replaced the speakers if they

blew up. In some cases, such as Altec and JBL, the factory would recone a speaker. Today, reconing is a very

popular option for players to keep their amp's speakers original. Reconing must be done correctly and with the

right parts so stick with a reputable reconing service that offers a warranty. In most cases, the reconed speaker

will sound nearly as good or as good as the original. In some cases, the speaker will sound even better. The

reconed Oxford 12K5 in my Deluxe Reverb sounds better than any original cone 12K5 I've heard.

There is a strong market for used speakers. Many times a player can find an original speaker to replace the non-

original speaker. Another option is to install vintage style speakers. Jensen has reissued the C10Q, P10R and

P12N and WeberVST makes many models of Jensen-style alnico and ceramic speakers.

One final note before you scope out the speaker chart -- there are exceptions to every rule and this especially

applies to Fender! So, if you see a factory stock P12P in a tweed Deluxe, don't be overly surprised.

Amp Model Speaker(s)

Bandmaster 5C7, 5D7 (wide panel) Jensen P15N

Bandmaster 5E7, 6G7 (3x10) Jensen P10R, P10Q, Oxford

12K5R-1

Bandmaster 6G7-A Oxford 12M6, Jensen C12N

Bandmaster AB763 and silverface Oxford 12T6, Jensen C12N,

Utah 12"

Bandmaster Reverb Silverface Oxford, Utah 12"

Bantam Bass Silverface Yamaha trapezoidal

Bassman 5B6, 5C6 Jensen P15N

Bassman 5D6, 5E6-A, 5F6, 5F6-A Jensen P10R, P10Q

Bassman 6G6 , 6G6-A, 6G6-B Oxford 12M6; Jensen C12N

Bassman AA864, AA165 Oxford 12T6; Jensen C12N;

Utah ceramic

Bassman Silverface Oxford 12T6; Utah; Rola

Bassman Ten Silverface CTS 10" ceramic

Champ 5C1, 5D1 Cleveland 6" alnico, Jensen P6T

Champ 5E1, 5F1 Oxford 8EV; Jensen P8T; CTS

8" alnico

Champ AA764, silverface Oxford 8EV

Concert 5G12, 6G12 Jensen P10R, P10Q

Concert 6G12-A Jensen P10R, P10Q, C10R;

Oxford 10K5

Concert AB763 Oxford 10K5, 10L5; Utah

V10LXC1

Deluxe 5B3, 5C3, 5D3 Jensen P12R

Deluxe 5E3 Jensen P12R, P12Q

Deluxe 6G3, AB763 Oxford 12K5-6

Harvard 5F10, 6G10 Jensen P10R

Musicmaster Bass Silverface CTS 12" ceramic; Oxford

126PJ4

Quad Reverb Silverface Oxford 12T6; Utah V12PC;

Rola

Princeton 5C2, 5D2, 5F2, 5F2-A Jensen P8T; Oxford 8EV;

Cleveland 8"

Princeton 6G2, AA964 Oxford 10J4; Jensen C10R

Princeton Silverface Oxford 10J4

Princeton Reverb AA1164 Oxford 10J4, 10L5; Jensen

C10R, C10N

Princeton Reverb Silverface Oxford 10J4; CTS

Pro 5A5 Jensen F15N (field coil), P15N

Pro 5B5, 5C5, 5D5 Jensen P15N

Pro 5E5, 5E5-A Jensen P15N

Pro 6G5, 6G5-A Jensen P15N; Oxford 15M6

Pro AB763 Jensen C15P; CTS 15" ceramic

Pro Reverb AA165 Jensen C12N; Oxford 12L6

Pro Reverb Silverface Oxford 12L6, 12T6; Utah,

Rola 12" ceramic

Showman 12 6G14, 6G14-A, AB763 JBL D120F with tone ring

Showman 6G14, 6G14-A, AB763 JBL D130F with tone ring

Dual Showman AB763 JBL D130F

Dual Showman Rev Silverface JBL D130F

Super 5B4, 5C4, 5D4, 5E4, 5E4-A Jensen P10R

Super 5F4 Jensen P10R, P10Q

Super 6G4, 6G4-A Jensen P10R, P10Q; Oxford

10K5

Super Reverb AA763, early AB763 Jensen C10R

Super Reverb AB763, silverface CTS 10" alnico or ceramic;

Oxford 10L6; Rola 10" ceramic

Super Six Reverb Silverface Oxford 10L6; CTS 10" alnico

Tremolux 5E9-A Jensen P12R; P12Q

Tremolux 6G9, 6G9-A Jensen P10Q or Oxford

10K5R w/tone ring

Tremolux 6G9-B Oxford 10K5

Tremolux AB763 Oxford 10K5, 10L5; CTS 10"

ceramic

Twin 5C8, 5D8, 5E8-A Jensen P12R; P12Q

Twin 5F8, 6G8 Jensen P12N

Twin 6G8, 6G8-A Jensen P12N; Oxford 12M6

Twin Reverb AB763 Jensen C12N; Oxford 12T6

Twin Reverb Silverface Oxford 12T6; EV; Gauss;

Utah; Rola

Vibro Champ/Bronco All Oxford 8EV

Vibrolux 5E11, 5F11 Jensen P10R

Vibrolux 6G11, 6G11-A, AB763 Oxford 12L6, 12M6

Vibrolux Reverb AA864, AA964 Jensen C10Q; Oxford 10L5

Vibrolux Reverb Silverface Oxford 10L5; CTS 10" alnico

Vibrasonic 5G13, 6G13-A JBL D130, D130F

Vibrosonic Reverb Silverface JBL D130F, K130F; Gauss;

EV

Vibroverb 6G16 Oxford 10K5

Vibroverb AA763, AB763 JBL D130F; Jensen C15N;

CTS 15" ceramic

A New Internet Resource: Over the last 12 months or so, I've had several people ask me to put together

some sort of Fender amp guide on my web site. A great idea, but I simply didn't (and still don't) have time for

such a venture. However, Mark Ware thought it was a good idea, too, and he put together a very informative

Fender Amp Field Guide. The site is nicely done and includes descriptions, pictures, and schematics for Fender

tube amps as well as other Fendercentric information.

Dating by Serial Number Update: The good news is that good progress is being made, but I am in fact, still

desperate (if you could only see the pitiful look on my face right now) for more info, especially for tweed, brown,

blonde and silverface amps. I have practically no information for some models like the Bassman 100 and other

"non-popular" silverface amps. And keep those blackface amp data coming! Also, I need more information from

reissue '63 Vibroverb amps and Custom Vibrolux Reverb amps.

I'm still trying to make sense of the "mysterious" production numbers and this is one area where I don't have a lot

of info: mainly because production numbers were not written on a lot of the tube charts. However, the next

article in this series (Part 4) will discuss some preliminary production trends (oh boy!). Were 1,000 or 10,000 or

100,000 Super Reverbs made? Stay tuned.

Reminder: We are still in need of information about any and all Fender tube amps. Everything is confidential,

we don't make record of who owns what amp in the database. What we need is the following:

1) Model name



4) Production number on the tube chart

5) Speaker codes and model (if speaker is original)




So please... send your amp data to the author c/o TCG Magazine. Thanks for your support and stay tuned for

Part 4 of this series!

Special thanks to Gregg Hopkins at Vintage Amp Restoration, St. Louis, Missouri for allowing me to

photograph the speakers from his inventory.

The author and his partners would like to thank those people who have sent us Fender amp information

(and you know who you are dahlings). Also thanks to the many dealers that we visit for allowing us to

make notes about the amps in their shops and at their guitar show booths.

DATING FENDER AMPS BY SERIAL NUMBER, PART IV

by Greg Gagliano

Copyright 2001, 20th Century Guitar Magazine

Yes, I know it's been exactly two years since the last installment in this series. Before we get into the amp info,

let me give you an update on what's been going on since I've been getting a lot of e-mail asking when the results

of the research is going to be available.

First, we (Devin Riebe, Greg Huntington and myself) must collect enough information to be able to date amps by

serial and determine production totals. "Enough" means an adequate amount of information to identify trends with

reasonable certainty. Sadly, the majority of information we gather does not have any details about possible date

of manufacture (pot dates, transformer dates, tube chart date codes, etc.) and without this important info, the

research takes longer.

Second, we are very dependent on information sharing. Devin, Greg and I do collect data on our own, but the

research goes much more quickly when we receive information from other sources, i.e. other people. And it's not

always easy to collect data ourselves. Some stores and dealers at guitar shows are very happy to let use inspect

their amps while others go ballistic and show us the door. Some collectors send information, others, upon first

contact, run away to their secret underground amp lairs never to be heard from again. But we persevere through

thick and thin.

This brings us to another topic which I will briefly mention. Many, many nice people from the United States,

Canada, South America, Europe, Australia, New Zealand, and Japan have contributed information to our

research and we are extremely grateful to all of you (and you know who you are dah'lings). I try my best to

answer each and every e-mail that I receive that either requests information or that submits info for our research.

Sometimes my answers are very short, but that's usually because I have a lot of other e-mail to read and answer.

It's not because I'm trying to brush any one aside.

Occasionally, we have to deal with mean people who do not wish to contribute data as they feel our research is

a one-way street. Honestly, I don't understand why they the bother writing if they don't want to contribute. Just

don't contact us, it's that easy, sheesh. I find their rhetoric tiresome, but as the authors of the Ampeg book and I

discovered during our Ampeg research, mean people are just part of the game. Ironically, it's the mean people

who most often ask to see our results: a one-way street, their way! Thankfully, the nice people far outnumber the

mean people and I again want to thank all the nice people for their support and encouragement as well as for the

information they provide.

Third, this is hard work. I could probably earn a Ph.D. from this project. Sometimes we need to take a break

and taking a break means not making any progress. We don't get paid for this and we all have day jobs. This is a

hobby for us and a labor of love, or insanity, take your pick.

Lastly, during the course of our studies we've come across several complicating factors that have slowed things

up. We're are more frequently encountering "parts amps". As with vintage Fender guitars, Fender amps (which

have lots of bolt-on parts) are being modified to make a less desirable amp (silverface) into s more desirable one

(blackface). Most of this are really easy to spot, but we still have to weed through this "parts amps" to figure out

what they are or aren't (be careful out there!). As mentioned in previous installments in this series, the majority of

Fender amps are serialized by model and/or chassis type. Many of these serialization schemes changed within a

given model. Also, there is some duplication of serial numbers for a given model. I will go into the details of the

serial number systems in the next article, but needless to say, it makes thing much more difficult for us.

If you would like to contribute information to our research you can do so by e-mail ([email protected]). All

the info is entered anonymously and we don't keep records of who sent what info.

Also please note, thanks to Mr. Gearhead (see below), we are no longer collecting data for any Fender tube

amp made after 1984, except Reissue models (we still want info for those!). Solid state amps were, and still

remain, excluded from our research. That means we don't need info for models such as The Twin, Pro Jr., Blues

Deluxe, Sedan deVille, etc. But we do want info for the '59 Bassman, '63 Vibroverb, '65 Twin Reverb, '65

Deluxe Reverb, '63 Reverb Unit, Custom Vibrolux Reverb (not a true reissue, but what the heck, we dig it) and

the newly released '65 Super Reverb. Call us vintage snobs, but we gotta draw the line somewhere.

For those of you with "modern" Fender amps (tube or solid state made after 1989) or Fender reissue amps, you

can go to FMIC's "Mr. Gearhead" web site (www.mrgearhead.net) which now explains how to date these amps

based on codes and serial numbers. We cracked the reissue amp code here first (kudos to us, see TCG Nov.

1997), but the Mr. Gearhead site is very convenient.

Now that we're up to date, let me pass along some interesting tidbits of info that have surfaced in the last year or

so.

There are some silverface Twin Reverbs from circa 1970 and Vibro Champs from circa 1973 without an "A"

prefix in the serial number (I hate when that happens). Several Twin Reverbs from late 1971 (specifically

October) have been observed with master volume chassis holes, but with conventional faceplates. This would

indicate that FMI was already thinking about the change to the master volume circuit in Fall 1971 and probably

even earlier.

Regarding model numbers, the model number for the Super Six Reverb is CFA7106 and the model number for

the Quad Reverb is CFA7104. It appears that the last digit refers to the number of speakers. Since these model

numbers are for the master volume models which shared the same chassis and circuit as the master volume Twin

Reverb, I have to wonder if the model number for the master volume Twin (2x12) would be CFA7102 and the

Vibrosonic Reverb (1x15) would be CFA7101. I haven't yet found the model numbers for these amps with the

ultralinear circuit. The "D" suffix in the model numbers for the Dual Showman Reverb (TFL5000D) and

Bandmaster Reverb (TFL5005D) denotes an amp for Domestic sale. Those with an "X" suffix, such as

TFL5005X, were for eXport sale.

And speaking of export amps, I have several reports from Sweden that Fender export models from that country

do not have the usual multitap power transformer with selector switch on the back of the chassis. Rather they are

hardwired for 220V to meet the Swedish equivalent of U.L. approval. Another interesting tidbit is that Fender

amps may have been distributed in Sweden by Hagstrom.

One frequently asked question I receive is "What is the difference between the AA763 and AB763 circuit for a

Super Reverb (or Twin Reverb or Deluxe Reverb)?" For those without access to schematics, here are the

differences:

AA763 AB763

Tone Cap .033 uf cap .047 uf cap

Reverb 4.7M resistor 3.3M resistor

Tremolo 56K resistor 100K resistor

Phase Inverter 27K/100K resistors 22K/82K resistors

Grid stoppers None 1.5K resistor

The most important difference is the addition of the grid stoppers (safety first!). The only major difference in tone

between the two circuits would be attributable to the different tone caps (.033 vs. .047). The .033 cap would

yield slightly more midrange, but I don't think it would be very noticeable.

For some models like the blackface Concert, there was no change in phase-inverter resistor values, and no

changes in tone stack cap values (fascinating!). And for other models, the tone stack did not change from .033 to

.047 uf, but rather from .033 to .022 uf. The Bandmasters also saw no change in tone stack cap values between

the AA763 and AB763 circuits. The "universal" changes do seem to be the oscillator circuit, cathode resistor

change from 56K to 100K, and the addition of the 1500-ohm grid stopper resistors.

Did you know that early blackface amps (1963) do not have white silk screening around the bright switches? It's

not certain when Fender added the white rectangle around the bright switches, but they are there by early 1964.

Whether this was added before the end of 1963 is not known (yet). This feature would have been phased-in at

slightly different times for the different amps as faceplates were ordered and used in somewhat different amounts

and at somewhat different rates for each model.

Some general information about cabinet construction: solid pine, finger-joined cabinet construction from 1946 to

circa 1972. An interesting feature on the tweed-style cabinets is the use of a dowel reinforcement in the top on

either side of chassis. You can't see the dowels unless the tweed covering is removed, but this reinforcement

prevented the wood from splitting due to the weight of the chassis.

Baffle boards were made of plywood from 1946 to 1962. Particle board (some call it MDF - medium density

fiberboard) baffles debuted in 1963 and were used through the early 1980s. The baffle board was removable on

amps made from 1948 to about 1972 and glued-in thereafter.

From circa 1972 to the early 1980s, the cabinets were no longer made from solid pine boards, but cheaper

laminated, multi-piece pine boards. Each side of the cabinet was made from several pieces about three or four

inches wide, glued side-to-side, to make up a plank the depth of the cabinet. These laminated cabs were not

finger joined, but rabbet joined. The baffle board on these rabbet joined cabinets was mortised into the sides and

bottom (i.e. not removable) to hold the whole thing together. That's why these post-1972 cabinets have the grill

cloth stretched across a frame that is attached by a velcro-like system to the baffle. CBS almost certainly went to

this construction method to save money, though at the expense of overall quality.

And with Fender, there are always exceptions to the rule. I have received reports of some pre-CBS blackface

amps with one or more sides made from a multi-piece board. As well, I have received reports of some particle

board bottoms used in master volume-era silverface amps.

I'm often asked if the marking on the inside of the cabinets are date codes. Sometimes date codes are ink

stamped on the inside of the cabinet (mainly blackface and silverface amps including the piggyback speaker

cabs), but those handwritten numbers you see in wax pencil or lumber crayon are actually matching marks. As a

worker would through a run of cabinets and fit baffles to each one, he would mark the cab and baffle so they

could be "married up" again after the baffle was grilled. The cabs were probably numbered sequentially within the

production run. The number did not have any relationship to a particular employee though Sam Hutton is known

to have marked the cabinets he assembled (usually in yellow lumber crayon) with an "S" superimposed over an

"H" which looks like a $ with two strikes instead of one.

We've received some interesting reports about some oddball amps. The first was a 1960 brown Super Amp.

The latest date code on it indicated 30th week of 1960 and the circuit and layout were neither 6G4 nor 6G4-A.

This must have been one of those "Leo messed with it" amps that Forrest White speaks of in his book. This

circuit is unique and transitional - part 6G4 in places, part 6G4-A in places, part "unique experimentation" in

places.

An October 1963 Deluxe Reverb was reported with transformers (all Schumacher) all dated to mid-1963,

except the reverb drive transformer which dated to December 62! The tube chart indicated the AA763 circuit,

but there were some very strange original resistor values inside. Specifically, the reverb drive tube's cathode bias

resistor was a 1K, 1-watt, instead of the normal 2.2K, ½-watt. The tail resistor in the phase inverter was 6.8K,

the plate load resistors in the phase inverter were 47K and 56K instead of the normal (for AA763) 100K. The

bias feed resistors were 68K instead of the normal 220K, and there was a disc ceramic cap on the board

connected between the phase inverter plates. The ceramic cap is more commonly found on brown and blonde

amps to prevent parasitic oscillation.

Some amp techs have observed examples of blonde and blackface amps with power transformers without

center-tapped filament windings. These amps are usually the ones that have "hum" problems if they don't have

100-filament resistors added. Somewhere along the line Fender went to a center-tapped filament winding and no

100-ohm filament resistors. These amps could be modified simply by lifting the center tap, and installing the 100-

ohm resistors in the usual place on the power lamp socket. If a filament in a tube shorts (happens most often in

power tubes) it is a lot cheaper to replace a 10-cent resistor or two, than an $100 power transformer.

Fender's sudden transition from cloth wire to thick PVC wire (in pastel greens, white & yellows) is well

documented by anyone who has ever pulled a chassis. Sometime in late 1968, the cloth covered wire went

away. However, several amps from the late '60s (non-reverb Princeton, Vibrolux Reverb, Bandmaster Reverb,

and possibly a Deluxe Reverb) with oddball wire have been reported. The Princeton Amp was an early-mid

1969 model entirely wired (factory original & stock) with thinwall, 22awg irradiated PVC (IPVC) wiring. IPVC

wiring is usually found in electronics like computers, not lo-fi amps. Keep your eyes peeled for wire with very

thin, cream to yellow insulation. It's likely IPVC.

Scanning a few internet discussion pages, I've noticed quite a bit of misinformation going around regarding

Fender tube amps mainly from people who haven't studied the available published literature on Fender amps, i.e.

they haven't been reading these articles in TCG. The good thing is that the misinformation is often corrected by

someone who is knowledgeable. One of the most common topics that falls into this category is early silverface

amps. Here's a very quick summary that may be helpful: the earliest silverface amps were made in 1967 not

1968, not all "drip edge" silverface amps are from 1968 or 1969 (they could be from 1967), not all "black line"

drip edge silverface amps have the blackface circuit except for Vibrolux Reverbs, Deluxe Reverbs, Princetons,

Princeton Reverbs, Champs, Vibro Champs, and Broncos.

I'll leave you with a bit of juicy info, namely, some preliminary production estimates for several random amp

models. This info will be further refined and presented in a future article (and y' all can hardly wait, I know).

Bassman (blonde) 12,000 units

Princeton Reverb (blackface) 19,000 units

Tremolux (blackface) 8,000 units

Vibrolux Reverb (blackface) 10,000 units

Vibroverb (reissue) 6,000 units

Special thanks to amp tech guru and fellow Jersey Boy, Mark Norwine at Carlson Amplification Inc., and Gregg

"Portaflex" Hopkins at Vintage Amp Restoration for contributing interesting and fun facts to this series.

DATING FENDER AMPS BY SERIAL NUMBER, PART V

by Greg Gagliano

Copyright 2002, 20th Century Guitar Magazine

They said it couldn't be done!

Over 6 years in the making!

Finally, what everyone has been waiting for!

How to date Fender amps by serial number!!

Okay, I know you're all just dying to skip ahead to the serial number tables but try to contain your excitement

and read through the article first. I promise the tables will still be there after you finish reading. Besides, no

article in the Dating Fender Amps by Serial Number series would be complete without some interesting

information, n'est ce pas?

FUN FACTS

Oddlings - Yet another printing error has surfaced, this time from the FEI (pre-CBS) days. A 1957 tweed

Vibrolux was reported with a tube chart printed with circuit "5E3" (tweed Deluxe) instead of the correct 5F11

(see photo). Clearly Fender wasn't afraid to use incorrect parts when they were in a bind. We also received a

report of a tweed 5G12 Concert. The 5G12 Concert is the earliest version from very late 1959 and early 1960

so the existence of a tweed example, while extremely rare, is certainly plausible since Fender was making lots of

tweed amps during the same time period. It’s unknown if the tweed covering was a mistake ("Oops, I thought

this was a 4x10 Bassman cabinet that I was covering") or intentional, perhaps as a special order.

Non-Schumacher transformers - It's been universally accepted that Fender only used Schumacher transformers

on amps made in the 1960s and 1970s. These are marked with EIA code "606" which is the company number

for Schumacher. Well, this universal "truth" was debunked when we found a bunch of amps with transformers

made by the Better Coil and Transformers company. These are marked with EIA code "831" and are most

prevalent during the 1966-68 time period. Some examples include a '66 Princeton Reverb and '6 Pro Reverb

with Better Coil output transformer, a '66 Deluxe Reverb and '67 Twin Reverb with Better Coil reverb

transformer, and a 1968 Vibro Champ with Better Coil trannies. These units look, and apparently sound, just

like the Schumacher-made units so it's easy to overlook that "831" code.

Working at FMI - I was able to interview a fellow (who wishes to remain anonymous) who worked at Fender in

1972-73 in the amp department. Although his job was somewhat limited, his recollections provided some really

fascinating insights to how the amps were built. For instance, he confirmed our assumption that the amp chassis

were put into stock after being stamped with serial numbers and that the chassis were pulled from the stock bins

randomly (just as with Fender guitar neck plates). He recalled, "We just went to a big bin every morning and

loaded our wheeled rack with a batch of whatever chassis we were working on that day. The boss came around

and said what we'd be building. The chassis weren't used chronologically. Probably the same as the pots and

transformers that we just dug out of the boxes. I think in the corners of the boxes were older pots remaining

from earlier dates... leftovers."

Regarding production he recounted the following information: "I think I remember being 'pushed' to come up

with 30 of the simpler chassis (Super Reverb?) per day. I think the better, older hands did 35 a day. Like I

said, there were 5 or 6 of us at the benches every day. But it wasn't always 'cool guitar' amps, sometimes I was

making Fender Rhodes Satellite amps on bent aluminum, sometimes only Champs. I remember two 'suits' from

upstairs standing behind me occasionally doing time studies. They actually held clipboards and stopwatches to

measure how long it took for me to attach various parts. Of course I tended to hurry more when they were

there, and I would fumble more, too."

Another really interesting fact was that he recalled that the eyelet boards were loaded/wired/soldered in Mexico!

"I remember the circuit boards were pre-made, from Mexico, easy to screw into the chassis. Same with the little

rectifier boards. When we had filled our cart we'd wheel it over to the Chicano chicks. They were something to

behold, all chatting away while soldering so quickly, it didn't hardly seem like they were looking at the amps.

After that the foreman would add the tubes, turn 'em on and set the bias."

Export models - We've confirmed that Fender amps were distributed by Hagström in Sweden. Not only that,

but to meet Swedish safety codes, Hagström removed the external voltage selector switch (fitted to all blackface

and silverface export models) and hardwired it internally (see photos). Notice that the original Fender back

panel was removed and replaced with a Hagström panel. One has to wonder where all those factory original

export back panels are! Maybe they'll show up on eBay. Another interesting tidbit is that a lot of Fenders were

imported into Australia in the late 1950s and early 1960s that were stock 110-volt (domestic US) units. The

Australian Fender Distributor then installed 240V - 110V stepdown transformers in the bottom of the cabinets.

Mid-1968 Super Reverb export model

modified by Hagström for the

Swedish market. Note the removal

of the voltage selector switch and

hard-wiring. Also note the vertical

black lines on the control panel

(found on earliest silverface amps)

and the large ceramic power resistors

coming off the power tube sockets

which indicates the AB568 circuit.

I Didn't Know That! Some Fender amp

expert I turned out to be. I just

discovered that the silverface

Bandmaster speaker cabinet (the big,

tall one without tilt-back legs) is ported

(see photo). I thought they were completely sealed units. I guess this is what the 1969 catalog refers to as

"large, individual specially designed baffles." And all along I thought the big n' tall silverface cabs were just a

macho thing to compete against the awesome looks of a Marshall half stack or full stack. But really, these cabs

were large because they were of a "special design" that “greatly improves tone and volume without distortion,

and permits optimum performance of the speakers. At least that's the reason according to the '69 catalog.

Also, another thing I've never seen before is a what appears to be a shipping tag of some sort (see photo). Note

the check boxes for DOM (domestic US model), EXP (export model), CSA (Canada model), STD (standard)

and SPEC (special). I have to wonder how often Fender used the SPEC check box and what features a

"special" amp or cabinet would have?! Since the new owner would have likely removed this tag immediately

upon arriving home, I’m amazed that the one in the photo has remained intact since mid-1968!

PRODUCTION

Along with dating amps by serial numbers, we were interested in determining production totals, if possible.

There is some debate about how to interpret the production code information on late '50s to mid-1967 tube

charts and Greg Huntington is still working with those. One thing we know for sure is that production codes can

help date an amp to a particular month within a given model run. Greg and I also disagree about determining

production from serial numbers. I will present my hypothesis here and let Greg present his side of the story in a

future article.

Unlike serial numbers used for most Fender guitars and basses, we know that serial number sequences are

unique to a particular model or a family of models of amplifiers. This is similar to the early '50s Telecaster and

Precision Bass having their own unique serial number system. Because the serial numbers are for a particular

model and that chassis were stamped sequentially, is reasonable to assume that the serial number infers the Nth

unit manufactured. Some caution is advised since it is likely that not all chassis were used due to defects or that

duplicate serial numbers may have been stamped. Since these two scenarios are probably a very small

percentage (or fraction of a percent) of total production, I’ve chosen to ignore them.

Another caveat is that it's impossible to determine the production totals for "family" models, that is, models that

share a common chassis. These "families" are: the Vibrasonic (6G13) and blonde Showman (6G14); the

narrow panel tweed Super, Bandmaster, and Pro; the brown Vibrolux (6G11) and blonde Tremolux (6G9); the

blackface Vibrolux (AB763) and blackface Tremolux (AB763); the brown Super, Pro, Concert and blonde

Bandmaster (6G7); the silverface Super Reverb and Bandmaster Reverb; the blackface Pro, Concert and

Bandmaster; the Vibro Champ and Bronco; the non-master volume Twin Reverb and Dual Showman Reverb;

and the master volume Twin Reverb, Quad Reverb, Super Six Reverb, Dual Showman Reverb, and Vibrosonic

Reverb. There is no way to separate out production for these models, but with enough data, we might be able to

do some frequency distribution and such to determine a rough estimate.

For the uniquely serialized models, the production estimates using my hypothesis, can be determined from the

serial number tables. This info may make some vintage dealers cringe when they find out how common some of

these amps really are, but that's just tough noogies. For example, the serial numbers for 5F6 and 5F6-A

Bassman amps run from BM00001 to BM04600 therefore we can conclude that there were about 4,600 units

made. How about those rarebird Vibroverbs? Well, the serial numbers for the brown Vibroverb run from

00100 to 00600 indicating a total production of around 500 units, and the serial numbers for the blackface

Vibroverb run from A00100 to A05300 indicating a total production of around 5,200 units. The brown Deluxe

is less common at about 4,800 units made (serial numbers run from D00100 to D04900). Anyway, you get the

idea.

Just remember that if you're interested in production from a "family" model listed above, you cannot use this

method. For instance, the serial numbers for tweed Bandmaster (3x10) run from S00001 to S03700. At first

glance you'd think there were about 3,700 Bandmasters made, but you'd be wrong. Remember, this model

shares a chassis with the narrow panel tweed Pro and Super. Therefore, the only thing we can infer is that there

were 3,700 tweed Bandmasters, Pros, and Supers made in total. Sure, you could assume that if production

was equal between models that there may have been 1,233 units of each model made, but currently we don't

have the data to support this kind of inference.

DATING

The tables are pretty much self-explanatory, but here are some guidelines to keep in mind when using the tables

to date your amp. First, the tables should be used as a guide only. You'll still need to look at various features

and date codes to absolutely confirm a year of manufacture. Large overlaps in years may be due to lack of

sufficient data (late 1940s to mid 1960s) or simply that the stamped chassis were used way out sequence (mid

1960s to early 1970s). Some, but not all, export models don't fit exactly into the sequence given and are usually

from a year or two later than the serial number would otherwise indicate. Silverface amps without the "A" prefix

are generally from the 1970-71 time period and the dating tables can be used to date them if you add an "A"

prefix.

Please note (this is very important) that there are many exceptions to the "rules" I have outlined here. Though

rare, there are some amps with bizarro serial number letter-prefixes and/or missing expected prefixes that don't

fit the tables. Thankfully, these aberrations are pretty rare. Just as with Fender guitars, you'll find serial numbers

that should fall in a certain year, but don't. Example: Vibrolux Reverb with serial number A756254 should be a

’77, but the latest date-coded parts date it to 1978. Some serial numbers have a letter prefix plus 4-digits

instead of the usual 5- or 6-digits. Likewise there are some serial numbers with an extra digit (usually a zero)

after the letter prefix. Again, these are rare and exceptions to the norm.

Finally, if you don't see a particular model or year listed, it is because 1) there wasn't enough data to generate a

dating table or 2) it falls under the “universal” scheme for A6-, A7-, A8-, A9-, B-, or F-series serial numbers.

In the case of early tweed amps, there simply isn't enough info available at this time to accurately date these by

serial number, though some rough guidance is provided. Same goes for Princetons made after 1966.

Don't get all bent out of shape if you see a model that wasn't "supposed" to be made in a certain year. Case in

point; we have documented two factory-original non-reverb blackface Deluxe Amps from January 1967. The

model was supposedly discontinued in 1966. Remember, FMI didn't like to waste anything (witness the Custom

and Swinger guitars) so using up the remaining AB763 Deluxe chassis wouldn't be a surprise.

DATING TABLES

For mid to late '70s silverface amps and early '80s "blackface" models, the serial numbers are date encoded

much the same way as Fender guitars from the late '70s:

A6 + 5-digits - 1976

A7 + 5-digits - 1977

A8 + 5-digits - 1978

A9 + 5-digits - 1979

B + 5-digits - 1975, 1976

F0 + 5-digits - 1980

F1 + 5-digits - 1981

F2 + 5-digits - 1982

F3 + 5-digits - 1983

F4 + 5-digits - 1984

F9 + 5-digits - 1979, 1980

Examples: Vibrolux Reverb with serial number A756154 (A7 = 1977), Princeton Reverb II with serial number

F077698 (F0 = 1980), and Super Reverb with serial number B10753 (B = 1975 or 1976). Note, there is

enough data for B-series Twin Reverbs (and variants) to differentiate between 1975 and 1976. These are listed

in the dating table. Unfortunately, there isn't enough data for other B-series models to identify the '75s from the

'76s, but with your help, hopefully we'll collect enough info to do this for a future article.

Bandmaster 5C7, 5D7 (tweed)

0001 to 0800 - 1953

5000 to 5500 - 1954

Bandmaster 5E7 (tweed)

S00001 to S00350 - 1955

S00350 to S01200 - 1956

S01100 to S01800 - 1957

S01700 to S02500 - 1958

S02500 to S03700 - 1959

Bandmaster 5G7, 6G7 (brown)

00001 to 01000 - 1960

Bandmaster 6G7, 6G7-A (blonde)

00001 to 02400 - 1960

02300 to 05100 - 1961

49000 to 58000 - 1962

58000 to 59200 - 1963

Bandmaster AA763, AB763 (blackface)

A00001 to A01700 - 1963

A01400 to A08000 - 1964

A07700 to A17000 - 1965

A16000 to A22000 - 1966

A20000 to A27000 - 1967

Bandmaster AB763, AC568 (silverface)

A26000 to A29000 - 1967

A28000 to A34000 - 1968

A33000 to A34000 - 1969

A34000 to A45000 - 1970-72

Bandmaster Reverb AA768, AA1069, AA270, TFL5005 (silverface)

A31000 to A35000 - 1968

A35000 to A45000 - 1969

A45000 to A49000 - 1970

A48000 to A54000 - 1971

A54000 to A59000 - 1972

A59000 to A66000 - 1973

A66000 to A77000 - 1974

A75000 to A78000 - 1975

A78000 to A80000 - 1976

Bassman 5B6 (tweed)

0001 to 0300 - 1951

0300 to 0400 - 1952

0400 to 0600 - 1953

Bassman 5D6, 5D6-A (tweed)

0600 to 0900 - 1954

Bassman 5E6, 5E6-A (tweed)

0100 to 0200 - 1955

BM00001 to BM00550 - 1955

BM00550 to BM01200 - 1956

BM01200 to BM01600 - 1957

Bassman 5F6, 5F6-A (tweed)

BM00001 to BM00400 - 1957

BM00400 to BM01500 - 1958

BM01500 to BM03100 - 1959

BM03100 to BM04600 - 1960

Bassman 6G6, 6G6-A, 6G6-B (blonde)

BP00100 to BP01100 - 1961

BP01100 to BP05000 - 1962

BP05000 to BP08400 - 1963

BP08400 to BP12000 - 1964

Bassman AA864, AA165, AB165 (blackface)

A00100 to A03800 - 1964

A03800 to A15000 - 1965

A15000 to A25000 - 1966

A24000 to A33000 - 1967

Bassman AB165, AC568, AA270, AA371 (silverface)

A32000 to A40000 - 1967

A39000 to A49000 - 1968

A48000 to A58000 - 1969

A58000 to A60000 - 1970

Bronco AB764 (silverface)

A19000 to A21000 - 1967

A20000 to A26000 - 1968

A25000 to A28000 - 1969

A28000 to A29000 - 1970

A29000 to A32000 - 1971

A32000 to A35000 - 1972

A33000 to A39000 - 1973

A39000 to A42000 - 1974

A42000 to A51000 - 1975

Champion 800 (tweed)

01 to 1000 - 1948-49

Champion 600 5B1 (tweed)

01 to 1300 - 1948-49

1300 to 1700 - 1950

1700 to 5000 - 1951-52

5000 to 5500 - 1953

Champ 5C1, 5D1 (tweed)

5500 to 6600 - 1953

6600 to 8000 - 1954

8000 to 9999 - 1955

Champ 5E1, 5F1 (tweed)

C00001 to C00800 - 1955

C00800 to C03100 - 1956

C03100 to C06000 - 1957

C06000 to C08800 - 1958

C08800 to C12500 - 1959

C12500 to C15500 - 1960

C15500 to C16800 - 1961

C17000 to C19000 - 1962

C19000 to C21000 - 1963

C21000 to C23000 - 1964

Champ AA764 (blackface)

A00100 to A02000 - 1964

A01900 to A05200 - 1965

A05200 to A12000 - 1966

A12000 to A12200 - 1967

Champ AA764 (silverface)

A12200 to A13900 - 1968

A13900 to A18000 - 1969

A18000 to A30500 - 1970

A30500 to A32000 - 1971

A32000 to A35000 - 1972

A32000 to A42000 - 1973

A42000 to A50000 - 1974

A50000 to A63000 - 1975

A63000 to A85000 - 1976

Concert 5G12, 6G12, 6G12-A (brown)

00001 to 02400 - 1960

02300 to 05100 - 1961

49000 to 58000 - 1962

58000 to 59200 - 1963

Concert AA763, AB763 (blackface)

A00001 to A01700 - 1963

A01400 to A08000 - 1964

A07700 to A08800 - 1965

Model 26 Deluxe (woodie)

100 to 1500 - 1946-48

Deluxe 5A3, 5B3 (tweed)

001 to 800 - 1948

800 to 1900 - 1949

1900 to 3000 - 1950

3000 to 5400 - 1951

5400 to 6800 - 1952

6800 to 7300 - 1953

Deluxe 5C3, 5D3 (tweed)

0001 to 1500 - 1953

1500 to 3600 - 1954

3600 to 5300 - 1955

Deluxe 5E3 (tweed)

D00001 to D01400 - 1955

D01400 to D03000 - 1956

D03000 to D05000 - 1957

D05000 to D06800 - 1958

D06800 to D09000 - 1959

D09000 to D10000 - 1960

D10000 to D11000 - 1961

Deluxe 6G3, 6G3-A (brown)

D00100 to D00900 - 1961

D00800 to D03800 - 1962

D03800 to D04900 - 1963

Deluxe AA763, AB763 (blackface)

A00100 to A00500 - 1963

A00500 to A02800 - 1964

A02800 to A05600 - 1965

A05600 to A06100 - 1966

A06100 to A06500 - 1967

Deluxe Reverb AA763, AB763 (blackface)

A00100 to A00300 - 1963

A00300 to A03900 - 1964

A03900 to A13000 - 1965

A12000 to A19000 - 1966

A19000 to A24000 - 1967

Deluxe Reverb AB763, AB868 (silverface)

A24000 to A26000 - 1967

A26000 to A28500 - 1968

A28500 to A33000 - 1969

A31000 to A33000 - 1970

A33000 to A34500 - 1971

A34500 to A37000 - 1972

A37000 to A39000 - 1973

A39000 to A42000 - 1974

A42000 to A43000 - 1975

A43000 to A45000 - 1976

Dual Showman AA763, AB763 (blackface)

A00100 to A01400 - 1963

A01400 to A01700 - 1964

A01700 to A04300 - 1965

A04300 to A08000 - 1966

A07800 to A12000 - 1967

Dual Showman AB763, AC568 (silverface)

A12000 to A12500 - 1967

A12500 to A15000 - 1968

Dual Showman Reverb AA768, AA769, AA270, TFL5000 (silverface)

A13900 to A16500 - 1968

A16500 to A22400 - 1969

A21700 to A25600 - 1970

A25600 to A37000 - 1971

A37000 to A50500 - 1972

A50500 to A68000 - 1973

A68000 to A99999 - 1974

A81000 to A99999 - 1975

B01000 to B15000 - 1975

B15000 to B68000 - 1976

Harvard 5F10 (tweed)

H00100 to H00500 - 1956

H00500 to H01400 - 1957

H01400 to H02000 - 1958

H02000 to H02600 - 1959

H02600 to H03400 - 1960

H03400 to H03500 - 1961

Musicmaster Bass CFA-7010 (silverface)

A00100 to A04100 - 1972

A04100 to A07900 - 1973

A07900 to A09500 - 1974

A09500 to A09800 - 1975

A09800 to A10500 - 1976

Princeton 5B2, 5C2, 5D2 (tweed)

2500 to 3600 - 1953

3600 to 4400 - 1954

4400 to 4700 - 1955

Princeton 5F2, 5F2-A (tweed)

P0001 to P00350 - 1955

P0001 to P01100 - 1956

P01100 to P02400 - 1957

P02400 to P03000 - 1958

P03000 to P04300 - 1959

P04300 to P07000 - 1960

Princeton 6G2, 6G2-A (brown)

P00100 to P01000 - 1961

P01000 to P05100 - 1962

P05100 to P07200 - 1963

P07100 to P09900 - 1964

Princeton AA964 (blackface)

A00100 to A02500 - 1964

A02500 to A07000 - 1965

A05000 to A10400 - 1966

Princeton AA964 (silverface)

A10000 to A11000 - 1967-68

A11000 to A15000 - 1969-70

Princeton Reverb AA1164 (blackface)

A00100 to A02100 - 1964

A02100 to A07500 - 1965

A05500 to A14500 - 1966

A14000 to A18700 - 1967

Princeton Reverb AA1164, B1270 (silverface)

A18500 to A19500 - 1967

A18900 to A21500 - 1968

A21500 to A25500 - 1969

A24000 to A25000 - 1970

A25000 to A26000 - 1971

A26000 to A27500 - 1972

A27500 to A30000 - 1973

A30000 to A32500 - 1974

A32500 to A34500 - 1975

A34500 to A36000 - 1976

Pro 5A5, 5B5, 5C5, 5D5 (tweed)

01 to 600 - 1948

600 to 1100 - 1949

1100 to 1700 - 1950

1700 to 2500 - 1951

2500 to 3500 - 1952

3500 to 4800 - 1953

4500 to 6000 - 1954

Pro 5E5, 5E5-A, 5E5-B (tweed)

S00100 to S00800 - 1955

S00800 to S01200 - 1956

S01200 to S01800 - 1957

S01700 to S02500 - 1958

S02500 to S03700 - 1959

Pro 5G5, 6G5, 6G5-A (brown)

00001 to 02400 - 1960

02300 to 05100 - 1961

49000 to 58000 - 1962

58000 to 59200 - 1963

Pro AA763, AB763 (blackface)

A00001 to A01700 - 1963

A01400 to A08000 - 1964

Pro Reverb AA165 (blackface)

A00100 to A02700 - 1965

A02700 to A09200 - 1966

A07000 to A10200 - 1967

Pro Reverb AA1265, AB668, AA1069, AA270 (silverface)

A10000 to A10500 - 1967

A10500 to A12000 - 1968

A12000 to A13300 - 1969

A13400 to A14500 - 1970

A14500 to A15000 - 1971

A15000 to A15600 - 1972

A15600 to A17200 - 1973

A17200 to A19700 - 1974

A19700 to A20000 - 1975

A20000 to A21500 - 1976

Quad Reverb CFA7104 (silverface)

A33000 to A37000 - 1971

A37000 to A50500 - 1972

A50500 to A68000 - 1973

A68000 to A99999 - 1974

A81000 to A99999 - 1975

B01000 to B15000 - 1975

B15000 to B68000 - 1976

Reverb Unit 6G15 (brown, blonde, blackface)

R00100 to R00900 - 1961

R00900 to R02600 - 1962

R02600 to R04800 - 1963

R04800 to R07400 - 1964

R07400 to R09800 - 1965

R09800 to R11000 - 1966

Showman 6G14, 6G14-A (blonde)

00001 to 00350 - 1960

00200 to 00800 - 1961

00800 to 01500 - 1962

01500 to 01800 - 1963

Showman AA763, AB763 (blackface)

A00100 to A01400 - 1963

A01400 to A01700 - 1964

A01700 to A04300 - 1965

A04300 to A08000 - 1966

A07800 to A12000 - 1967

Showman AB763 (silverface)

A12000 to A12500 - 1967

A12500 to A15000 - 1968

Super incl. Dual Professional (tweed)

01 to 400 - 1946-47

500 to 1200 - 1949-51

2000 to 4300 - 1952-53

4500 to 5500 - 1954

5500 to 6100 - 1955

Super 5E4, 5F4 (tweed)

S00100 to S00800 - 1955

S00800 to S01200 - 1956

S01200 to S01800 - 1957

S01700 to S02500 - 1958

S02500 to S03700 - 1959

Super 5G4, 6G4, 6G4-A (brown)

00001 to 02400 - 1960

02300 to 05100 - 1961

49000 to 58000 - 1962

58000 to 59200 - 1963

Super Reverb AA763, AB763 (blackface)

A00100 to A00600 - 1963

A00600 to A06000 - 1964

A05900 to A13000 - 1965

A11000 to A20000 - 1966

A20000 to A27000 - 1967

Super Reverb AB763, AB568, AA1069, AA270 (silverface)

A26000 to A29000 - 1967

A27000 to A35000 - 1968

A35000 to A45000 - 1969

A45000 to A49000 - 1970

A48000 to A54000 - 1971

A54000 to A59000 - 1972

A59000 to A66000 - 1973

A66000 to A77000 - 1974

A75000 to A78000 - 1975

A78000 to A80000 - 1976

Super Six Reverb CFA7106 (silverface)

A33000 to A37000 - 1971

A37000 to A50500 - 1972

A50500 to A68000 - 1973

A68000 to A99999 - 1974

A81000 to A99999 - 1975

B01000 to B15000 - 1975

B15000 to B68000 - 1976

Tremolux 5E9, 5E9-A (tweed)

0001 to 00650 - 1955

00650 to 01000 - 1956

01000 to 01300 - 1957

01300 to 01700 - 1958

01700 to 02700 - 1959

02600 to 03300 - 1960

Tremolux 6G9, 6G9-A, 6G9-B (blonde)

00100 to 01000 - 1961

00900 to 04200 - 1962

04200 to 05900 - 1963

Tremolux AA763, AB763 (blackface)

A00100 to A00500 - 1963

A00500 to A03700 - 1964

A03200 to A05700 - 1965

A05200 to A08000 - 1966

Twin 5C8, 5D8, 5D8-A, 5E8, 5E8-A (tweed)

001 to 500 - 1953-55

A00200 to A00725 - 1956-57

Twin 5F8, 5F8-A (tweed)

A00010 to A00725 - 1957-59

Twin 6G8, 6G8-A (blonde)

00001 to 00100 - 1960

00100 to 00225 - 1961

00225 to 00400 - 1962

00400 to 00525 - 1963

Twin Reverb AA763, AB763 (blackface)

A00100 to A01200 - 1964

A01200 to A04300 - 1965

A04300 to A07000 - 1966

A07000 to A10400 - 1967

Twin Reverb AB763, AC568, AA769, AA270 (silverface)

A10500 to A11300 - 1967

A10500 to A16500 - 1968

A16500 to A21400 - 1969

A21400 to A25600 - 1970

A25600 to A37000 - 1971

A37000 to A50500 - 1972

A50500 to A68000 - 1973

A68000 to A99999 - 1974

A81000 to A99999 - 1975

B01000 to B15000 - 1975

B15000 to B68000 - 1976

0100 to 3400 - 1970

Vibrasonic 6G13, 6G13-A (brown)

00001 to 00350 - 1960

00200 to 00800 - 1961

00800 to 01500 - 1962

01500 to 01800 - 1963

Vibro Champ AA764 (blackface)

A00100 to A02000 - 1964

A01200 to A08100 - 1965

A08100 to A16000 - 1966

A16000 to A20500 - 1967

Vibro Champ AA764 (silverface)

A19000 to A21000 - 1967

A20000 to A26000 - 1968

A25000 to A28000 - 1969

A28000 to A29000 - 1970

A29000 to A32000 - 1971

A32000 to A35000 - 1972

A33000 to A39000 - 1973

A39000 to A42000 - 1974

A42000 to A51000 - 1975

A51000 to A53000 - 1976

Vibrolux 5F11 (tweed)

F00001 to F00300 - 1956

F00300 to F00900 - 1957

F00900 to F01500 - 1958

F01500 to F02800 - 1959

F02800 to F04000 - 1960

F04100 to F04400 - 1961

Vibrolux 6G11, 6G11-A (brown)

00100 to 00700 - 1961

00700 to 03700 - 1962

03400 to 05500 - 1963

Vibrolux AA763 (blackface)

A00100 to A01300 - 1964

Vibrolux Reverb AA864 (blackface)

A00100 to A00800 - 1964

A00800 to A03600 - 1965

A03600 to A08300 - 1966

A08300 to A10700 - 1967

Vibrolux Reverb AA864, AA964, AB568, AA270 (silverface)

A10700 to A11000 - 1967

A11000 to A12000 - 1968

A12000 to A13700 - 1969

A13700 to A23400 - 1970

A23400 to A24500 - 1971

A24500 to A25000 - 1972

A25000 to A27000 - 1973

A27000 to A31500 - 1974

A31500 to A33000 - 1975

A33000 to A34000 - 1976

Vibrosonic Reverb (silverface)

A44000 to A50500 - 1972

A50500 to A68000 - 1973

A68000 to A99999 - 1974

A81000 to A99999 - 1975

B01000 to B15000 - 1975

B15000 to B68000 - 1976

Vibroverb 6G16 (brown)

00100 to 00600 - 1963

Vibroverb AA763, AB763 (blackface)

A00100 to A05300 - 1964

YOU CAN STILL HELP!

Sadly, these tables do not mean that our research is finished. We still need more data to fine tune existing dating

schemes (including the overlap in the "universal" A+6 digit and F series) and to provide dating tables for missing

models and/or years. Also, we're still researching the "mystery of the production number" on the tube charts of

late '50s through mid-1967 amps. Please continue to send submit info to us via e-mail.

Thanks again to everyone who contributed information to make these dating tables possible. We hope you find

them useful!!

Special thanks to Sixten Forsén at EDGAR Audio in Sweden for the information and photos, to Sam Hartley for

the information and photos, to Greg at Retro Sound in Australia and Paul Mastradone for the excellent info.

Extra special thanks to my co-researchers, Devin "The Tweed King" Riebe and Greg Huntington, for their

invaluable assistance with collecting data and information about Fender amps.

About the author: Greg Gagliano is going on vacation. You can try to contact him by e-mail, but don't

be surprised if you get a pre-recorded message.

Excerpted from Dating Fender Tube Amps by Serial Number

http://www.superchamp.dk/papers/dating_fender_tube_amps.htm

READABILITY — An Arc90 Laboratory Experiment http://lab.arc90.com/experiments/readability

Dating Fender Tube Amps by Serial Number

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