Major Score: 68 Pro Reverb for $400

[Regis]

I scored big time this week and got a 1968 Pro Reverb in superb condition for $400. The guy's story was that he was unemployed, his truck needed tires, his mama was sick and he was on the lam from his mortgage company for his unpaid doublewide payments. I am not making this up.

The amp is a silverface drip edge. He brought it over and it looked good but didn't sound all that good, the power tubes looked worn. I was going to open it up and look inside but decided it was worth the risk and did the deal.

After I paid him and he left I opened it up and saw that it was essentially like it was the day it left the factory! The only apparent change is an old orange drop in the tremolo section. Dunno if the tubes are original but dig what is in it: RCA 12AX7 preamp tubes, Telefunken 12AX7 reverb and driver tubes, RCA 6L6GC's, and a Mullard GZ34 rectifier.

It has the cool wire cloth wiring, the good blue caps, and the original Utah orange back speakers.

The reverb didn't work but I took it over to my friend Kerry and we, well... he fixed it for me, one of the reverb spring retainers was broken and he had an old tank he cannibalized one from. The pots were scratchy but that is easily fixed with contact cleaner. The power tubes looked worn out and they definitely were. I put a pair of JJ 6L6GC's I had in my tube collection in it and biased it up, then fired it up, and OH MY GOD!!!

This amp has instantly become my favorite of all the amps I own. (Except maybe for my Kaybreaker 720) I am telling you it has classic Fender Tone Of The Gods. Everything ever described about clean Fender tone is there, and when dimed it has the sweetest overdrive ever. When I stepped on my Tubescreamer I had to stop and change my shorts.

It was seriously dusty inside the cabinet, and while I was vacuuming it out there were a few other bonus items I found. A guitar cord that didn't function, a few picks, and, well... I did a webpage with more pics. Check it out to see what else I found.

Calling Bob P., don't worry, I have no intention of modding this amp, other than rewiring for EL34's, modding the normal channel into a Marshall style preamp, changing the baffle to accomodate a fifteen, removing the tolex and covering it with alligator skin, swapping all the caps for orange drops, and drilling holes in the chassis for a master volume, a presence control, and effects loop jacks. I was planning to drill holes and install casters but I didn't want to reduce the vintage value of the amp any.

Just kidding.

Is it ok if I put a grounded AC cord on it and remove the death cap?

[TD_Madden]

Your "look what else..." has no picture.....

[Regis]

Your "look what else..." has no picture.....

It's a link to a webpage, it works for me.

http://www.regiscoyne.com/proreverb

[Tom Phillips]

Your "look what else..." has no picture.....

Same here. Just text shows. No pictures.

[Regis]

Same here. Just text shows. No pictures.

ok, I'll fix it

[Regis]

Ok, try it now, I had the pic pointers going to the pictures on my hard drive. It should work now.

[stokes]

That last "find" would explain his financial distress.Nice amp though,real clean.

[TD_Madden]

OK, I see 'em. Great find!

[Tom Phillips]

Very interesting. This is the first SF I remember seeing that still had the good Blue tubular caps AND such extensive SF circuit changes.
Nice bit of historical documentation.
Tom

[Regis]

Very interesting. This is the first SF I remember seeing that still had the good Blue tubular caps AND such extensive SF circuit changes.
Nice bit of historical documentation.
Tom

Yes, I'm going to have to pull the chassis again and look it over with the BF and SF schematics to see exactly what I have. It obviously has the snubber caps and bias balance, I didn't look to see if the tone caps were .022 or .047.

[TD_Madden]

OK, I'll bite....will you leave the circuitry intact as a "historically-important" piece, or modify to improved performance standards?? ;-)

You did say it has become your favorite...so much for the much-maligned SF circuitry!

Just wonderin' is all.

[Regis]

OK, I'll bite....will you leave the circuitry intact as a "historically-important" piece, or modify to improved performance standards?? ;-)

You did say it has become your favorite...so much for the much-maligned SF circuitry!

Just wonderin' is all.

Well TD, like I said this amp really sings. I was just kidding Bob in that post above.

How much better would it be if I started to mess with it? I don't know and as long as it sounds good I don't want to know. When I got my BF Bandmaster it sounded like shit. It really needed a recap and new tubes, and sounded great when I did that. The Pro still has the original caps and they look good, aren't burst or anything and the amp doesn't have any filter cap hum. The bias resistor gives me 35ma on the JJ's and I used the balance pot to match them. That's biased a little colder than I usually do, using the formula's I could go up to 45ma, but again as long as it sounds good there's no need.

The only thing I might do is put a grounded cord and disconnect the death cap, and if future power tubes give me bias problems I'll have to address that. What do you think?

I tell you, when I opened this thing up I felt like the guy that opened up King Tut's tomb, it was that clean.

[TD_Madden]

I definitely think a new pwer-cord/death-cap removal is a good idea. You always hang-onto both of them.

[Tom Phillips]

Yes, I'm going to have to pull the chassis again and look it over with the BF and SF schematics to see exactly what I have. It obviously has the snubber caps and bias balance, I didn't look to see if the tone caps were .022 or .047.

What's most interesting to me is that the amp has what I call the combo bias circuit. The big resistors on the power tube cathodes. First time I have seen those in a '68 that had blue tubular caps on the board. What resistance value are those cathode resistors?
Also the PI seems to be half BF & half SF.
I guess that I shouldn't be surprized. Different factory stock curcuit variations continually seem to show up in old Fender amps.

Tom

[stokes]

There were a lot of "cross over" circuits in that era when they were switching from the Black to Silverface,they were more interested in the $$$ so they didnt waste parts and you see a lot of mixes in some amps.I would at least change those filter caps,even tho you dont see any problems,almost 40 years on those caps,you will surely notice an improvement in the amps response with fresh ones.I dont particularly care about preserving an amps "snob appeal" for some collector down the line,particularly with a SF,nor am I interested in potential re-sale value,I buy an amp to play and if I think it sounds better with some mod,I have no qualms about doing it.That said,I would also change that bias balance to a bias control so you can bias a set of NOS tubes that the amp would be so happy with.These two"mods" would not be so detrimental to the value of a SF amp,in my opinion anyway.Beautiful amp,Regis,nice score indeed,good luck with it.