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1972 Fender Pro Reverb Siverface?


ZettaVita

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$750 seems about right for that amp, as long as everything's working o.k. It's a pretty loud amp and not that easy to sell, so make sure it's what you want before you take the plunge.

 

Bingo.

 

That would be an awesome gigging amp, AND you and it would be unique in your area. 40 watts is also a great size for jamming with full bands w/drums. Get it tuned up and crank the crap out of it.

 

And it won't drop in value like a fish, like a new amp. It'll ALWAYS be worth more than most.

 

BUY IT.......................

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I am not completely sure. I think '72 is a good year for the amp. '79 would not be.

 

Silverfaced amps are not all the same as the Blackfaced ones, everybody knows that. But some years in the later ones they did changes the earlier silverfaced ones didn't have. So it really matters.

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Do you know if it has the AA668 circuit or the AA1069? Many people prefer the latter - see below...

 

"The AB668 circuit introduced a change to the bias section where the capacitors off the grids of the power tubes and the resistors off the cathodes were changed in an attempt to make the circuit more stable. The wiring placement of the amp was also changed. The result of these changes was a noticable decrease in sound quality. In the AA1069 the cathode was put back to ground to help resist high-frequency feedback caused by moving the wires that previously ran under the circuit board to the top of the board. A 5U4 rectifier replaced the previously used GZ34 rectifier at the same time, which decreased the headroom and increased the sag. A 3-position ground switch was added and the cab size was changed so the Pro and Twin chassis could share the same cab."

 

As for the price $750 is close to average (based on Ampware's numbers) for a '72.

 

http://ampwares.com/amplifiers/fender-silverface-pro-reverb/

 

If you like that big punchy, Fender 6L6 sound, I'd say you'd be in heaven with that amp. [thumbup]

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Do you know if it has the AA668 circuit or the AA1069? Many people prefer the latter - see below...

 

"The AB668 circuit introduced a change to the bias section where the capacitors off the grids of the power tubes and the resistors off the cathodes were changed in an attempt to make the circuit more stable. The wiring placement of the amp was also changed. The result of these changes was a noticable decrease in sound quality. In the AA1069 the cathode was put back to ground to help resist high-frequency feedback caused by moving the wires that previously ran under the circuit board to the top of the board. A 5U4 rectifier replaced the previously used GZ34 rectifier at the same time, which decreased the headroom and increased the sag. A 3-position ground switch was added and the cab size was changed so the Pro and Twin chassis could share the same cab."

 

As for the price $750 is close to average (based on Ampware's numbers) for a '72.

 

http://ampwares.com/amplifiers/fender-silverface-pro-reverb/

 

If you like that big punchy, Fender 6L6 sound, I'd say you'd be in heaven with that amp. [thumbup]

That's good info there, Pup.

 

Not sure when AB668 and AA1069 were used, but I am kinda thinking these were both pre-'72?

 

Having said that, one of the things the later silverfaced ones have is different transformers. While the pwer transformer using the 5U4 cannot be made to use the GZ34/5AR4, many of these silverfaced ones have been re-done in whole or part to more "Blackfaced"...said that to say, is not only do many go for the earlier Silverfaced ones, but it's also a fools game guessing which amps are "factory", and which have been altered.

 

Later silverfaced ones I am pretty sure have lots of other changes, including lots of negative feedback, and bigger output trannies. I am talking about the Pro and the Viblolux. These two in particular got changes from Fender a lot of other amps didn't.

 

I could be wrong about some of this...again, I am going by memory, and I might not have been completely right even back when I remembered.

 

Having said all that, any are pretty good, and worth having. Just that they are not all the same amp, and not all may be in the 750$ value category.

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That's good info there, Pup.

 

Not sure when AB668 and AA1069 were used, but I am kinda thinking these were both pre-'72?

 

... Later silverfaced ones I am pretty sure have lots of other changes, including lots of negative feedback, and bigger output trannies.

 

No the AA1069 lasted until 1982. The one he's looking at seems to be near a possible transition between those two - why I mentioned it.

 

As for negative feedback - that loop is the first thing to get rid of and it's usually one snip. The bright cap on the volume knob is next. Two snips to tonal bliss. [biggrin]

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No the AA1069 lasted until 1982. The one he's looking at seems to be near a possible transition between those two - why I mentioned it.

 

As for negative feedback - that loop is the first thing to get rid of and it's usually one snip. The bright cap on the volume knob is next. Two snips to tonal bliss. [biggrin]

Sorry....I meant both BEFORE 1972.

 

Anyway, I'm getting confused. The only thing harder than Pro/Vibrolux circuits changes is my head. Back when I was into them, less was written about them, but yet more circuit drawings would "appear" for me than I could learn about. I mean all the 70's Fender amps.

 

Probably, whatever I might think I know should be taken with a grain of salt. For a long time, there were "rumors" that Fender never made drawings for certain changes or amps, then at times someone would have like 10 new drawings. I think a lot of stuff that was said to be wired "wrong" by someone, even Fender, might have been more rumor just cause a lot of us didn't know certain circuits were supposed to exist.

 

I bet these days, there are some guys who might know more about them than all of what was written when I was "hip" to Silverfaced stuff.

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Sorry....I meant both BEFORE 1972.

 

Anyway, I'm getting confused. The only thing harder than Pro/Vibrolux circuits changes is my head.

 

Yeah, lots to be confused by. The Vibrolux actually used the same circuit from 68-82 - the AA270. I think they added the dreaded pull-boost to the circuit in the mid/late 70s. That's easily fixed though. And there were certainly plenty of unique variations where some assembler subbed this or that part. Plus as you say, many have been modded - but they can be modded back too. When I got my 77 Deluxe Reverb the first channel had been hot rodded by a well-known amp modder. I had an amp tech friend return it to stock.

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Yeah, lots to be confused by. The Vibrolux actually used the same circuit from 68-82 - the AA270. I think they added the dreaded pull-boost to the circuit in the mid/late 70s. That's easily fixed though. And there were certainly plenty of unique variations where some assembler subbed this or that part. Plus as you say, many have been modded - but they can be modded back too. When I got my 77 Deluxe Reverb the first channel had been hot rodded by a well-known amp modder. I had an amp tech friend return it to stock.

I know of at least 3 diffirent circuits, or rather, versions of the Vibrolux from 68-69 Silverfaced to late 70's or early 80's. My understanding is that the Pro and the Vibrolux have been the exact same amp during that time, although, that might only be true for some of that time period.

 

I guess another way of putting it, is what I was wrong before about some of it, I might be wrong about more. Although I might want to stress, a lot of what I "knew" was from what I had read or what was considered common knowledge.

 

Silverfaced Deluxe Reverbs are realtively easy, in that they didn't change all that much. Basically, rectifier/power transformer change, and very minor circuit changes, like the pull boost you mention here.

 

Bassmans, lots of different ones, but they were more often than not re-named a bit, like "Bassman 50", "Bassman 100" became "Bassman 135", etc.

 

Pros, Vibrolxes, and some others, hard to tell. They didn't have anything different on the outside to give any hints there were changes. And they liked to put whatever ideas they had into them. As you pointed out, from AA669 to AA1069, major difference. But nothing on the outside of the amp to tell anyone they are any different. And that, to me at least, makes it interesting.

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