Vox AC30CC w/ VVR

[skelt101]

Hello everyone,
Recently, I had a VVR installed in my Vox AC30CC. It has been really nice getting the power tubes into the mix. When using the Normal Channel, the amp sounds great! However, when plugging into the Top Boost Channel, the sound is relatively quiet and thin. (Almost an "out of phase" type sound, if that makes any sense...) Would this be considered "normal operation"? Could there be a cold solder joint or bad cap in the Top Boost circuit? (The amp tech who did the install repaired some bad/cold solder joints in the rectifier circuit. I guess the factory wasn't on their "A-game" the day my amp was made...) I have already swapped out tubes to eliminate that possibility. Thanks for your help everyone!

[UR12]

Hello everyone,
Recently, I had a VVR installed in my Vox AC30CC. It has been really nice getting the power tubes into the mix. When using the Normal Channel, the amp sounds great! However, when plugging into the Top Boost Channel, the sound is relatively quiet and thin. (Almost an "out of phase" type sound, if that makes any sense...) Would this be considered "normal operation"? Could there be a cold solder joint or bad cap in the Top Boost circuit? (The amp tech who did the install repaired some bad/cold solder joints in the rectifier circuit. I guess the factory wasn't on their "A-game" the day my amp was made...) I have already swapped out tubes to eliminate that possibility. Thanks for your help everyone!

No, this is not normal

[skelt101]

Thank you for the reply Dana! Any ideas what's going on there? Also, I have another concern regarding the amp's reverb and tremolo effects: they gradually diminish as the VVR is turned down. I was told the reason for this is there is not enough voltage to drive those circuits. It seemed to be a logical explaination. This is not a huge deal for me, as I rarely, if ever, use them. Just curious... Thanks again!

[10thTx]

I have installed Dana's VVR on two cathode biased amps just using the VVR on the LTPI and PA.

I simply hooked up the reverb to a different B+ node that is not having the voltage lowered and they both work just fine.

And I'm very pleased with the VVR. Nice feature to have.

With respect, 10thtx

[greiswig]

I have installed Dana's VVR on two cathode biased amps just using the VVR on the LTPI and PA.

I simply hooked up the reverb to a different B+ node that is not having the voltage lowered and they both work just fine.

And I'm very pleased with the VVR. Nice feature to have.

With respect, 10thtx

I'm curious as to whether you tried scaling just the PA and not the inverter? I'm putting a VVR3 in a Hot Cat 30, and wondering what all I should be scaling and what the effects on feel and sound are of various ways of doing it.

Thanks!