'68 Super Reverb completely modded - is it the AB763 now?

Sharky77

Was just looking in the chassis of my Super today and was wondering if it's exactly the AB763 circuit? When I bought it the seller said it had been 'blackfaced' so I knew it wasn't original inside. Since then I had the mains transformer replaced for a 240v and a few resistors changed but nothing major. I'm pretty sure all the caps used are very highly regarded (Jupiter and F&T) but wanted to see if any amp specialists on here could advise on whether it is the full AB763 circuit. 

Speakers for anyone curious are 2 original CTS alnicos and 2 Jensen C10Qs. 

Thanks!

Olly 

ecc83

Ugh!

Dave.

Sharky77

@ecc83 care to elaborate a little? 

Nerine

Looks like a stir fry. 

Sharky77

Zero noise floor though and sounds incredible. Since owning it I have sold a '64 Pro Amp, '67 Super and '67 Bandmaster - all of which had the fabled blue moulded caps. This thing sounded better than all of them. I know it isn't the prettiest to look at from an amp geek perspective though   

Nerine

Sharky77 said:

Zero noise floor though and sounds incredible. Since owning it I have sold a '64 Pro Amp, '67 Super and '67 Bandmaster - all of which had the fabled blue moulded caps. This thing sounded better than all of them. I know it isn't the prettiest to look at from an amp geek perspective though   

It’s probably brilliant. I can’t tell by looking at it. 

I just thought it looked like the egg noods I get from Tesco. 

I can’t comment on it technically. Other than the lead work looks more, shall we say erratic, than on most builds I’ve seen. That likely means piss all. I’m not an amp tech. 

It’s cool regardless. 

In a stir fry way. 

ecc83

Sharky77 said:

@ecc83 care to elaborate a little? 

I know "that's how they make 'em" but it just offends my technician's eye and the lack of any cable colour system makes servicing that much harder. Out of deference I shall NOT post the internals of an Artisan 30!

Dave.

Sharky77

ecc83 said:

Sharky77 said:

@ecc83 care to elaborate a little? 

I know "that's how they make 'em" but it just offends my technician's eye and the lack of any cable colour system makes servicing that much harder. Out of deference I shall NOT post the internals of an Artisan 30!

Dave.

They did look similar to this originally but also pretty much everything has been changed in this amp - it would have originally had the brown turd caps

RiftAmps

No, it's not the fully correct AB763 circuit for a Super Reverb, although it is VERY close. The mid-caps for both tonestacks should be 22nf and not 47nf as currently installed, although some players prefer this arrangement. YMMV.

There are some other values that I cannot read, so cannot confirm further.

It's definitely not AA763 (PI and OPV grid stoppers), nor is it AB568.

Sharky77 said:

I'm pretty sure all the caps used are very highly regarded (Jupiter and F&T)

I can only see Sprague and Mallory caps.

Sharky77

Thank you @RiftAmps for your reply - you sent me on an immediate research quest about the mid caps. Very interesting! Been watching your YouTube channel the last couple of months and really enjoying it. I'd love to bring my amps to you for any work but you are just a little too far away. 

Not sure why I thought the yellow caps were Jupiters. Are the Sprague and Mallory caps well regarded in this amp? I'm sure the filter caps are the black F&Ts

ICBM

If it sounds better than all your other ones, leave it alone!

Sharky77

Haha! To be fair the Bandmaster was on a par with it. But there was too much overlap to justify keeping both and the Bandmaster was a more attractive buy for somebody because it had all the original Ajax caps.

I wasn't going to touch it but something like that is an easily tried mod, which can be easily switched back. However I will be leaving it alone, you're right. If it's the 22nf for Super is it also that for a Vibrolux? I read that the 47nf is most common in this circuit in the amps with 12" speakers