Vox AC30 cc without rectifier tube!!

[Jestapali]

OK, I don't know much about amp technicalities, but I don't think this is normal:

Some time ago I bought an AC 30 CC1 used. I read about the issues that some can have blowing the rectifier tube if you use the Stand by option. No problem if the Stand by is always on. Mine has been always on with no problems at all.

So, yesterday I decided to change the tubes (I was feeling them old and noisy). Big was my surprise when I saw that the rectifier tube position was empty, no tube at all. WTH! Can the amp work like this?, how? ... I was honestly puzzled.

I changed all the tubes and added a rectifier tube as well, the amp sounds better now. But, HOW WAS THIS THING WORKING WITHOUT THE TUBE RECTIFIER??!!

[beauzooka]

It could have been internally modified to not use a rectifier. You might want to take a peek inside.

[adamrobertt]

It's either modded or this is one of the VOX amps that has a solid state rectifier. The amp almost certainly wouldn't work at all without a rectifier tube, since that's what converts AC to DC which is what the amp needs internally...

[Jestapali]

The Custom Classic model is supposed to be just tube rectified (GZ34). I guess that someone might have modified it to solid state rectifier (only explanation I can imagine, since the rectifier tube socket was empty!), but I don't even know how to check that (this amp is a pain for changing tubes and look inside). In any case, it sounds awesome to me after switching to JJ.

[Embenny]

To be honest, I'd take it to an amp tech to be safe.

If it's been modded with a solid state rectifier, you've now plugged a tube rectifier into a socket that may or may not be connected to anything. It had an audible effect, meaning...something...is happening internally. You're relying on some unknown model's unknown mood keeping you from electrocuting yourself or blowing up your amp.

Rectifiers are one of the most electrically significant components of an amp (up there with electrolytic caps), so if there's a chance it's been modded, the safest thing (for you, and for the amp) is to get it thoroughly checked out before playing it more.

[jorri]

The ac30cc1 would not power without a rectifier.

I did have one with a solid state rectifier. You can buy tube shaped ones that plug in the socket. Otherwise, an actual tech may just solder in 4 diodes (or whatever it is...) somewhere- they take up no space basically.

(you sure you didn't buy mine??)

~IMO the rectifier in the AC30 is sonically better as solid state. The tube rectifier is the wrong circuit to 'sag' but rather cause a slight overpowering constantly. Same does not apply to other amps that may benefit. I just found a slight perceived headroom, and a bit less asthenic with a solid state but not exactly massively, like 3% better and it saves having potentially no amp when the tube blows.
[tech whizzes call me out on that if I'm incorrect but i seem to recall it was backed up somewhere with graphs]

[jorri]

**underpowering (sorry, tube would be underpowering)

[Jestapali]

Thank you guys. Probably the best I can do is to take out the tube rectifier and leave it as it was. I guess that if rectifier diodes were added without disconnecting the tube rectifier, it could be somehow unsafe ...No idea, honestly.