Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: allstonma on October 31, 2021, 07:22:43 pm

Title: 1964 Vox AC30/6 with back panel reverb, fix or tank replace ?
Post by: allstonma on October 31, 2021, 07:22:43 pm

Hey All
I have a 1964 Vox AC30/6 twin-reverb with the Vox back panel reverb on my bench. Someone removed the reverb tank with wire cutters. The original replacement tank is really hard to find (its also said to be crap).
Client would like it to make reverb, wondering what the best approach is ? Is there a non crap commodity tank that's a drop in replacement. Do I need to rebuild the reverb circuit ? If so any suggestions ?
Thanks
AllstonMA

Title: Re: 1964 Vox AC30/6 with back panel reverb, fix or tank replace ?
Post by: glass54 on October 31, 2021, 07:55:56 pm

Hi allastonma,
I don't really know this model (haven't seen one in Aussie  :icon_biggrin:) but a schematic would be useful.
You may want to have a look at this article for interest: http://www.voxshowroom.com/uk/amp/ac30SRT_square_head.html (http://www.voxshowroom.com/uk/amp/ac30SRT_square_head.html)
Sorry couldn't be more helpful but I believe the original rev was a little crap. Lots of mods done if you look on the net.
Its an interesting situation you're in and I'm sure others here will be more helpful and probably guide you with a schematic.
Looking forward to you solutions  :laugh:
Kind regards
Mirek

Title: Re: 1964 Vox AC30/6 with back panel reverb, fix or tank replace ?
Post by: allstonma on October 31, 2021, 08:29:05 pm

Here is the schematic @ Glass54's suggestion

Title: Re: 1964 Vox AC30/6 with back panel reverb, fix or tank replace ?
Post by: sluckey on October 31, 2021, 08:39:57 pm

Measure the resistance of the reverb transformer secondary. It it's very low ohms I'd try a standard Fender 4AB3C1B.

Title: Re: 1964 Vox AC30/6 with back panel reverb, fix or tank replace ?
Post by: allstonma on October 31, 2021, 08:50:05 pm

Thanks Sluckey
Unfortunately it seems to have been removed along with the reverb tank.

Title: Re: 1964 Vox AC30/6 with back panel reverb, fix or tank replace ?
Post by: sluckey on October 31, 2021, 09:50:59 pm

Quote from: allstonma on October 31, 2021, 08:50:05 pm

Thanks Sluckey
Unfortunately it seems to have been removed along with the reverb tank.

Well, in that case get the standard Fender reverb tranny and that tank.

Title: Re: 1964 Vox AC30/6 with back panel reverb, fix or tank replace ?
Post by: Jalmeida on October 01, 2023, 08:12:06 am

Quote from: allstonma on October 31, 2021, 07:22:43 pm

Hey All
I have a 1964 Vox AC30/6 twin-reverb with the Vox back panel reverb on my bench. Someone removed the reverb tank with wire cutters. The original replacement tank is really hard to find (its also said to be crap).
Client would like it to make reverb, wondering what the best approach is ? Is there a non crap commodity tank that's a drop in replacement. Do I need to rebuild the reverb circuit ? If so any suggestions ?
Thanks
AllstonMA

Sorry to resurrect a dead thread. But curious if and what you did to resolve the reverb issue?

Title: Re: 1964 Vox AC30/6 with back panel reverb, fix or tank replace ?
Post by: AlNewman on October 01, 2023, 06:23:18 pm

There must be an old graveyard out there, where all these amps go to die.  I wonder where it is?