[HAM] Recapping AO-29

[David Anderson]

Hi Bruce,

I don't have an AO-29 schematic in front of me, but if you're thinking 
of restoring or rebuilding one of these, you definitely need the 
schematic, and you can count the components on the schematic.

I usually check the stock resistors and replace them if they're more 
than ~10% off, depending on their function in the circuit. Some are 
more critical than others. The more controversial issue would be 
whether or not replacing all the carbon composition resistors with 
metal films or carbon films would change the sound. Some might feel it 
does, others might feel it doesn't. I haven't tried an entire "shotgun" 
rebuild, so I can't comment authoritatively on it. You can, of course, 
still get carbon composition resistors.

As to whether or not rebuilding an amplifier can "hurt" your 
sound.....well, it can change it, and not always predictably, depending 
on what was wrong with it to begin with. I had a situation in Los 
Angeles where a guy brought a Rhodes piano to me with a noise issue no 
one else had been able to fix. I fixed it, but in doing so, I 
eliminated some distortion that he *liked*. I had to explain to him 
that he couldn't have it both ways. Rebuilding the amplifier won't have 
any effect on the TG output, but it will most likely have an effect on 
the way the whole system sounds.

And yes, I would make sure everything downstream of the Tone Generator 
was working optimally before I messed with the TG itself.

To close, yes, you can put the entire circuit back the way the original 
schematic says it should be. Will you regret doing so? That's between 
you and your ears.

David A.

On Tuesday, August 22, 2006, at 01:33  PM, Bruce Gordon wrote:

> David,
>   Would you know how many caps and resistors are in
> this amp?  Maybe just go ahead and redo all of them
> *if* there's not too many?  I'm assuming that a
> "recap" of an amplifier cannot hurt your TG sound.
> Threads have pretty much been in consensus that this
> is a good thing to do rather than a TG recap. With all
> the discussion lately of TG recapping, I'm just
> wondering if doing the amp could have any effect which
> a person would regret.
> Thanks,
> BG