Another Fender ?

Bobby Boggs · From: Upstate SC.

Would some of you folks with a book on old Fender amps tell where to look on the amp to find the date of manufacture.The amp is 68 or 69 Super Reverb.I think it was purchased in Dec 67.It was the first silver face to come to our neck of the woods.
Also is it true that the very first silver face Fender Super Reverbs where the same as the last black face Supers?? Thanks in advance.------------bb

Donny Hinson · From: Glen Burnie, Md. U.S.A.

Bobby, I have seen at least 3 (which makes me believe there are at least 5) different schematics for the BF Twin-Reverb. The differences are minimal, (mostly having to do with the output biasing) and don't have a great deal of effect on the sound.

Actually, any pre master-volume version has, more or less, the same sound and essentially the same circuitry. Certainly, the early silver-faces follow suit. This is a great steel amp, and only lacks in power for really big gigs. The earliest T/R's were rated at 60 watts, and even the 120 watt-rated versions put out just a little more useable sound...perhaps 80-90 watts.

Here's where to go to find your production date...
http://rexc.com/services/date.htm#fen_amps

[This message was edited by Donny Hinson on 05 September 2001 at 09:03 AM.]

Rick Johnson · From: Wheelwright, Ky USA

Bobby
If its a 68/69 the amp will have a aluminum
trim around the baffle, if it has not been
tampered with. If it looks original and
does not have the aluminum it is at least
a 1970. If it has a master volume that will
put it up to around 72/73
It can also be dated by the speakers.
Determine the mfg of the speakers and
go to www.webervst.com and look at the links
for speaker mfg and dates.
Again this is if the speakers are original.
It probably has Utah, Oxford speakers.
Good luck

Rick

D Schubert · From: Columbia, MO, USA

The Fender Amp Field Guide is pretty useful for dating amps, too.
http://www.ampwares.com/ffg/

Bobby Boggs · From: Upstate SC.

Thanks again guys.You've been very helpful.According to Amp-Wares the Super was manufactured the 49th week of 1967.And it may have the AB763 circut,or Black face circut as some call it.If only I knew what"ceramic power resistors"looked like,I would know for sure.Sadly I'm not kidding,never seen the inside of any amp.But I'm going to have a look tomorrow. ----bb Ps. I will unplug it first.

Donny Hinson · From: Glen Burnie, Md. U.S.A.

Bobby...those "ceramic power resistors" are rectangular, and they have a square cross-section. They are usually tan or grey, and smooth on 3 sides, and the fourth side has a sandy-gritty appearance. They will have axial leads, and their values will be stamped in red or black ink on the side opposite the "sandy" side.

Jay Ganz · From: Out Behind The Barn

The main thing different about the late
60's Fenders was the type of coupling
capacitors that were used. These transfer
the audio signal from one stage of the
preamp section to the next & on to the
output tubes while blocking DC voltage
at the same time. The blackface models
used the blue & white cylindrical shaped
caps with the lead wires on either end,
while the later 60's were shorter dark blue with the lead wires on the bottom.
You can also date these amps with the
date code that's on the back of the pots.

------------------

"Turn up the dang STEEL!!!"

Bobby Boggs · From: Upstate SC.

The amp has AB763 stamped on the tube chart.However Amp-Wares says that Fender had a lot of these charts printed up and CBS used them long after they switched to the silver face circut.Thanks Donnie for the good explanation.-------bb

Bobby Boggs · From: Upstate SC.

This is a quote from AMP WARES:
"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."
Donnie, is this what you are referring to??--bb

Bill Terry · From: Bastrop, TX

Bobby,
Pull out the chassis and look for something soldered from the tube socket to ground that looks sorta like this:
http://www.ktronics.com/cpr.htm

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Home Page

[This message was edited by Bill Terry on 06 September 2001 at 11:31 AM.]

Bobby Boggs · From: Upstate SC.

OK, I do not see any signs of the big honking ceramic resistors.Thanks Bill. Jay, my capacitors are medium blue with white labels and lead wires on both ends.Does this sound right for a black face circuit??-------bb

[This message was edited by Bobby Boggs on 06 September 2001 at 11:41 AM.]

Patrick Smith · From: Shreveport, LA, USA

Bobby,

go to the Fender Field Guide site mentioned above and get the layouts for the Black Face twin reverb and the Silver Face twin reverb.

The most telling regarding the BF vs the SF circuit changes are in the bias supply and the phase inverter. Look all the way to the left inside your chassis and note how your bias pot is wired up.....look at the layout....that will tell you right there. Also follow where the wire comes off of the bias pot to the board....does it hit between two resistors....or just one?.....you can look immediately to the right of that at the phase inverter circuit (the last preamp tube to your left....assuming the pots are furthest from you and the tubes closest)....read the values of the resistors in the PI and compare with the layouts.....my guess is, if it's a silver face twin, you have the silver face circuit....which can VERY EASILY and accurately be put back to black face specs.....also, while your in there, look on the reverb footswitch jack, do you see a ceramic .002 uF cap from the jack going to ground?.....if so, clip it and notice how much better your reverb sounds.

Now once you've black faced it, the next step is to route the never used Normal Channel through the reverb circuit, change the output coupling cap to .022 and then put that channel to tweed specs!....this new channel will flat out kick the reverb channels butt!....big time!.....(here he goes again!.....LOL)

PMS

Jay Ganz · From: Out Behind The Barn

Bobby,
Most of the amps I've seen with those
blue & white capacitors (like yours),
have very little of the CBS circuitry
in them. Usually, it's those other
caps that signal the start of the
CBS tinkering.

Bobby Boggs · From: Upstate SC.

Well boy's looks like I hit pay dirt on this baby.

I talked to Greg from Amp-Wares at length.He assures me the Super has the AB763 circut.Or better known as the Black Face circut. It appears to be one of a handfull of silver face Super Reverb's that slipped through without the CBS changes.As I stated earlier this amp has never had a wrench on it till today.Thanks to all who helped!---bb

Jody Carver · From: KNIGHT OF FENDER TWEED

That dammed CBS messed everything up,,,they even put a "block" on my TV after their take
over,,,couldnt watch anything but CBS,,,,,they had that CBS eye watching all of
us.....The key word for what CBS stood for was "Constant Bull S%it,,,,thats what the employee's called the corporate office.

To get a speaker replaced for a customer,it would have to go through the "board of directors meeting" to get a neck replaced..you would have to speak with Paley
or Stanton,,,,,top guns at CBS that would include Walter Cronkite for final approval.
There are numerous schematics for Twin reverb amps as well as all other models,they had people on the payroll getting paid just to make those changes,,,should have changed the people and left the amps and the schematics alone...

Michael Frede · From: Sonoita, AZ, USA

Fender used to stamp a date inside the chassis between the power transformer and the circut card,same as they did on the necks and P/U cavities on their guitars.

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