TO Vox Cambridge Rvb pot value?

[Rob Mercure]

Hey Folks,

Well, looks like "Mercure Professional Services" is back in the electronics repair business - mostly I've been wiring houses for the past few years but my electronics services seem to be in demand again. I've got a Thomas Organ "Vox" Cambridge Reverb that I'm getting back in shape - my first TO "Vox" - and one customer complaint was the reverb pot taper - the reverb came on too fast. After opening up the beast, cleaning it and establishing a safely grounded power input, I noticed that the reverb pot had been replaced with a 500K Allen Bradley sealed pot. Now while these AB pots are some of the best methinks that the replaced pot and the "taper" complaint seem a bit "coincidental." <grin>
Does anyone have the schemo for this beast or know the specs for the original reverb pot?

Thanks Rob

[Ray Ivers]

Rob,

I just sent you the print via E-mail, which indicates a 250K (probably audio-taper) reverb pot. I bet the AB pot is linear taper.

Ray

[Rob Mercure]

Hey Ray,

Thanks for the schemo - but this is the Thomas Organ "Vox" which is SS.

Rob

[Rob Mercure]

&quot;good enough&quot;

So as not to keep y'all in "suspenders" I swapped the 250K control (misstated in my original post) for a 5K which was as close as I could guess at the original control's value with some e-mail help from Enzo and Ray (thanks again guys). While it did improve the situation some the reverberated signal still came on too soon and I believe there is some decoupling issues between stages that are to blame. But the customer didn't want to pay for a recap job so he accepted it as is - maybe whoever buys it will have me recap it.

Rob

[R.G.]

So as not to keep y'all in "suspenders" I swapped the 250K control (misstated in my original post) for a 5K which was as close as I could guess at the original control's value with some e-mail help from Enzo and Ray (thanks again guys). While it did improve the situation some the reverberated signal still came on too soon and I believe there is some decoupling issues between stages that are to blame. But the customer didn't want to pay for a recap job so he accepted it as is - maybe whoever buys it will have me recap it.

Rob

It's too bad that the customer doesn't have the vision to spring for the recap. The Cambridge Reverb was my first amp, back when dinosaurs roamed the earth. A well maintained Cambridge with an original Utah "bulldog" 10" is a very nice sounding small amp, much better than you'd expect by it being a solid state amp.

The Thomas Vox solid state amps in general are much better sounding than other SS amps before or after.

I'm in the process of writing up a Thomas Vox repair manual. I hate to see these things get dumped. Within their limits, they're good amps, even if they're not the worlds best.

If your customer wants to unload it, please tell him I want it.

[Rob Mercure]

Hey RG,

Haven't checked this post in a while - sorry. I'll contact the music store tomorrow. I did PM you but with no reply - you might check that so that we can establish regular e-mail to get you the amp. And I'm glad that someone who'll appreciate it wants it. Fer the record when I got it back together the reverb still came on too soon for the customer but if you turned it up a bit along with the tremelo it was "the summer of love all over." <grin>

Rob