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Just bought a '70 Super Reverb

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6/23/2000 9:54 AM

Just bought a '70 Super Reverb

Forgive my state of over-excitement, but I just bought a 1970 Super Reverb last night (for a fair price, but not an absolute steal) and am hoping to solicit some early advice from experienced owners/repairers out there before I open the thing up.

I showed up to see the thing expecting -- if it was OK -- to then take it home and plan for the full Blackface conversion to get it to its best (the guy just said it was "a 70s model", was selling it for a friend who has gone into a rest home. That guy was the original owner) but on inspection it turned out to be the AB763 circuit...

QUESTION ONE: isn't that the one where they corrected some of the early silverface "improvements" and put it back more to blackface specs anyway?

Naturally, I also figured I'd be replacing the speakers too, but it has four original, non-re-coned CTS 10" alnicos in it - or anlico-looking designs, anyway (code 137 7013).

QUESTION TWO: What's the general opinion on these CTS speakers?

Now, current condition: it's somewhat tatty cosmetically, but ALL there: all parts, knobs, bits and pieces, no visible mods. Even has the original footswitch, the original owners manual, hang tag, inspection ticket... The guy was a gigging bar-band guitarist all his life and never seemed to clean this thing (grille cloth nicotine stained, spider webs in the speaker frames, etc), but took very good care of this amp otherwise (local service stickers inside dated '74 and '79 -- probably the last re-tubing).
Most importantly, it sounds fantastic as it is, though I know it certainly needs a re-tubing and new filter caps.

FINAL QUESTION: Aside from the re-tubing and cap job, does anyone recommend any other jobs to put this into its best possible condition (on paper, anyway)? When I open it up I'll know what sort of tone and coupling caps are in it, but were they generally pretty good in this circuit/year?

Thanks in advance for any help. Thought I had enough amps... but who could resist!

All the best,

Dave

6/23/2000 10:30 AM
Paul Stansfield	Hi Dave, how's it going? Sounds like you got yourself a good amp. If you check out this link: http://www.ampwares.com/ffg/super_reverb_sf.html you might get some of the info you need. It looks like some of the early S/F Super Reverbs did indeed have the AB763 circuit. Did you ever get that Lightning finished?! Cheers Paul

6/23/2000 5:16 PM

You verified it's a 1970 be date codes on the transformers? If so, I find it very difficult to accept that it's a factory stock AB763. Particularly since the AA568 and AA1069 were designed in the intervening years. I would accept that it may be a factory original AB763 if the amp was an early 68. Just because it may have a tube chart that says "AB763" doesn't mean the guts are really BF. Fender continued to use the old tube charts until they ran out.

The 1069 removes some of the CBS crap that was in the 568 circuit, but they *never* took them back completely to the 763 circuit.

The CTS alnicos are considered to be good sounding speakers. Keep them.

6/23/2000 7:51 PM

exactly! My super reverb had a tube chart that said AB763 but when I opened it and it was really an AA568. But, the good news is it was only a matter of taking out a couple resistors and fixing the inverter stage to 'blackface' it.

I find the 568 circuit to not be all that bad sounding anyway. It is after all a matter of your ears. I once heard this blues cat playing through an ultralinear twin and he sounded superb.

nic

6/26/2000 3:40 PM

Yeah, as you all pretty much guessed this is not actually an AB763 inside (as I explain over on the "Repairs" forum -- sorry for starting two threads!).

Easily rectifiable, though, and while I hold with Bare's comments that you don't want to get ahead of yourself and make a decent older silverface sound worse by "blackfacing" it, I've made a few changes inside already and it's a formidable sounding amp.

Thanks for your help,

Dave

6/24/2000 3:42 PM

Whatever circuit or CBS variation is almost irrelevant at this point. What matters is that you like the sound, I would suggest using it as is for awhile at least. Save the 'circuit improvements' for a future time. Once you start 'replacing' parts especially the resistors, which have drifted dramatically by now, you will be changing the sound.. it will be more like what it originally sounded like, but it may not be what you like about it now. So if you must, at least keep, identify and label ALL removed parts so that you have a return road in case you want to go back.

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