Help identifying Fender Super Reverb circuit

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Help identifying Fender Super Reverb circuit

Postby sdeyoung on Thu Apr 13, 2017 11:03 pm

I picked up a Super a few weeks ago. The guy told me it was a 68', when I checked the serial number it matches for 69'. No big deal, I bought it anyways since i've been looking for one for quite some time now. The tube chart says it's an AB763 circuit, but from what I read, Fender had a surplus of these tube charts and may have included them on some of the silverfaces even after they changed the circuit. I'm wondering if there's any other way, other then getting a tech to look at the circuit, to identify if it is indeed a AB763 or not. Either way, the amp sounds amazing, it's in pretty good shape considering it's age. Still has RCA tubes and original CTS alnico speakers. Still pretty happy with my purchase even if I do find out it's not an AB763.
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Re: Help identifying Fender Super Reverb circuit

Postby BetterOffShred on Fri Apr 14, 2017 9:14 pm

You could pull the head, and take detailed pictures of the board and component placements, and possibly record values of capacitors or take pictures so that they can be seen. These can easily be compared to the layout diagrams from this era to pinpoint the circuit! :D

Just be careful pulling the head, pull the tubes first, disconnect reverb tank etc. and don't put your fingers in it in case any of the caps still have a charge.

-Brett
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Re: Help identifying Fender Super Reverb circuit

Postby sdeyoung on Fri Apr 14, 2017 9:26 pm

Yeah I thought of that but I think I'll let my amp tech do that for me lol
someone mentioned that you could find out by the xformer. Not sure if this is true or not?
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Re: Help identifying Fender Super Reverb circuit

Postby BetterOffShred on Fri Apr 14, 2017 10:31 pm

Anything from the 60's has had quite a long period of time to have been messed with. So I wouldn't trust any exterior indications myself personally. My Bassman looks like an AB165 from the outside, but it's not anymore. Pulling the head is easy man. Literally pull the tubes, disconnect the reverb tank connectors, and then loosen up the 4 strap screws, support the head, or do it upside down on a bench, and then pull the nuts off, drop the screws out and slide the head out the back of the cabinet. super cake. Then take a shitload of pics of it for us to all fap to and identify your circuit! 8)
-Brett
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Re: Help identifying Fender Super Reverb circuit

Postby stratele52 on Sat Apr 15, 2017 8:22 am

sdeyoung wrote:
someone mentioned that you could find out by the xformer. Not sure if this is true or not?


Not sure ? Ask Google ; Dating Fender transformer
Yes is true and it is well know from Fender collectors
http://www.svvintageamps.com/dating.php

You have a great amp.

Ask you tech to put a 3 prong cord
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Re: Help identifying Fender Super Reverb circuit

Postby slider313 on Sat Apr 15, 2017 7:25 pm

If it's a '69 then it can't be a stock AB763 circuit. The circuit changed in May of '68 to the AB568.
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Re: Help identifying Fender Super Reverb circuit

Postby stratele52 on Sat Apr 15, 2017 8:24 pm

slider313 wrote:If it's a '69 then it can't be a stock AB763 circuit. The circuit changed in May of '68 to the AB568.


You could be right, but with CBS everything could happened....

I fix a Vibrolux Reverb with the aluminium trim wich must be a AA270 circuit , see note ( no sticker inside) . After studying the circuit inside, it was a AA964

Note; http://ampwares.com/?brand=fender&line=vibrolux
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Re: Help identifying Fender Super Reverb circuit

Postby JJman on Sat Apr 15, 2017 9:01 pm

Pull an output tube and check the resistance from the cathode pin to ground. Wait for the meter to stabilize if needed since there may also be a cap involved. If the reading is 0-10ohms, it is AB763 or AA1069 or AA270. If over 70ohms it is AB568.
-If it says "Vintage" on it, it isn't.
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Re: Help identifying Fender Super Reverb circuit

Postby stratele52 on Sat Apr 15, 2017 10:43 pm

JJman wrote:Pull an output tube and check the resistance from the cathode pin to ground. Wait for the meter to stabilize if needed since there may also be a cap involved. If the reading is 0-10ohms, it is AB763 or AA1069 or AA270. If over 70ohms it is AB568.


Short answer, if you see resistor on cathod ( pin 8 ) , it look to be a AB768
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Re: Help identifying Fender Super Reverb circuit

Postby slider313 on Sun Apr 16, 2017 3:22 pm

stratele52 wrote:
slider313 wrote:If it's a '69 then it can't be a stock AB763 circuit. The circuit changed in May of '68 to the AB568.


You could be right, but with CBS everything could happened....

I fix a Vibrolux Reverb with the aluminium trim wich must be a AA270 circuit , see note ( no sticker inside) . After studying the circuit inside, it was a AA964


Aluminum trim doesn't make it a AB568 or AA270. The silverface cosmetics came about in the spring of 1967.
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Re: Help identifying Fender Super Reverb circuit

Postby sdeyoung on Sun Apr 16, 2017 6:37 pm

Thanks guys, I guess the best thing to do will be pull the amp apart which I'll do soon. :)
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Re: Help identifying Fender Super Reverb circuit

Postby Naked Clarke on Mon Apr 17, 2017 3:21 am

slider313 wrote:
stratele52 wrote:
slider313 wrote:If it's a '69 then it can't be a stock AB763 circuit. The circuit changed in May of '68 to the AB568.


You could be right, but with CBS everything could happened....

I fix a Vibrolux Reverb with the aluminium trim wich must be a AA270 circuit , see note ( no sticker inside) . After studying the circuit inside, it was a AA964


Aluminum trim doesn't make it a AB568 or AA270. The silverface cosmetics came about in the spring of 1967.


It was the fall of 1967.
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Re: Help identifying Fender Super Reverb circuit

Postby Factory Guy on Mon Apr 17, 2017 9:21 pm

The Aluminum Trim amps started in JANUARY of 1967, or at least cabinets did. I owned a tall "Drip Edge" 2x12 Bassman cabinet with the slot port with a factory production date stamp of January 1967 inside the cabinet and the interior of the speaker baffle board.

As for the AB763 circuit it was used into 1969 on some amps and maybe even later depending on the amp model. I currently own a 1969 Fender Bandmaster Reverb Amp and cabinet that has the same turret circuit board layouts as the 1965 and 1966 Super Reverb Amps in my collection. The only difference between the 3 amps inside is the '65 and '66 Super Reverbs have nice neat wiring job done at the factory, blue caps everywhere, and the 1969 Bandmaster Reverb Amp has the ugly looking gum-gob caps everywhere and looks like someone vomited the wiring between all the components, and the Supers have a 2 ohm output transformer where the Bandmaster Reverb has the 4 ohm output transformer, tranny manufacture/production codes, and the screw location on the knobs.

As a side note I use the Bandmaster Reverb Amp with a 4 ohm open back 4x10 cabinet and it sounds very much like a Super Reverb, which it should since they are the same amp :D It is just slightly noisier at idle than my Super Reverbs are.

I think it depends on who was working at Fender that built the amps, the longer employed amp line people probably kept building the amps "like they used to" with the new more "cost effective" guts until Fender actually ran out of the older turret boards for the various amp models and then HAD to build amps with the "improved" post AB-763 circuit design boards. I've seen plenty of "gum-gob" cap amps on the '67-'69 AB763 Super Reverb Amp and Bandmaster Reverb Amp turret boards.

The Fender company was quite famous for not throwing anything away and using inventory to the last piece.

Fix anything that needs fixing, leave everything else alone, unless you KNOW you are going to make it better!

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Re: Help identifying Fender Super Reverb circuit

Postby slider313 on Wed Apr 19, 2017 1:19 am

Naked Clarke wrote:
It was the fall of 1967.


I would have to agree to disagree. It was late spring when production took place to show the new cosmetics at the summer NAMM show. Most, if not all were pre production amps and for the show only. By August the silverface cosmetics were produced side by side with the out going blackface amps.

This Deluxe Reverb is from August of '67.

Image

Image
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Re: Help identifying Fender Super Reverb circuit

Postby Dean Jr. on Wed Apr 26, 2017 5:05 pm

Silverface cosmetics were introduced in April, 1967. The first changes to the circuits from Blackface era to Silverface circuit era took place in May of 1968....and not all amps were changed then. Some were not changed until later. The use of earlier tube charts in amps with later circuits was common. IN fact, they would even use charts from other models....slap it in there and get it gone. I had a near mint and all original 1957 5E3 Deluxe that had a tube chart for a 5F6A Bassman. I also had a 1968 SF Dual Showman with an AB165 BAssman tube chart....all original and exc cond amp.
Re: the Vibrolux reverb. That amp did receive some changes in May of 1968. Those changes would be easily reverted to the 1964 circuit...perhaps without any telltale signs of work being done.
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