VVR

[Andyjoe]

I installed Dana's vvr on my 6v6 plexi and now my volume controls dont work. Is there a trick on how to make it work on a amp with 2 volume controls?

Andy

[KellyBass]

??

Do you mean to say that your volume controls no longer effect the volume of the amp? Is the amp stuck wide open?...or not making any sound at all?

[Colossal]

Andy,

The volume controls and VVR work independently of one another. Did you scale just the power section, power section and phase inverter, or the whole amp (preamp, PI, and power amp)? If you scaled the whole amp, did you add the additional film cap and 1M resistor to ground on the grid of the first tube as well as from the second grid input? This is outlined in the VVR installation documentation. The second stage grid comes after the 470k/470k mixing resistor pair. So, from that pair of resistors you should have a lead going to a cap to the grid pin of the second stage with a 1M from the grid pin to ground. If your volume controls are not working sounds like something is odd with the wiring...if you scaled the whole amp (and it sounds like you did).

[sliberty]

Show us the schematic of your amp, and tell us how yo uinstalled the VVR. There shouldn't be any "trick" needed. Possibly just an error that needs correcting.

[Andyjoe]

I scaled the whole amp,my volume is wide open. I have a 1 input plexi
that is internally jumperd but I have a bright vol and a normal volume.
My grid resistors were at the socket so I put a res and cap on each of the grids of v1, and a res and cap of the wiper of each volume pot.

Andy

[UR12]

I scaled the whole amp,my volume is wide open. I have a 1 input plexi
that is internally jumperd but I have a bright vol and a normal volume.
My grid resistors were at the socket so I put a res and cap on each of the grids of v1, and a res and cap of the wiper of each volume pot.

Andy

you have to have something wired wrong if neither of your vol controls work. Do you have any pics of your install. The VVR should work great on that amp. Do you get anything at all out of the speaker. What voltages do you have on your power tubes? I am out of town in San Francisco at the moment and have limited time on the internet but will try and help.

[Andyjoe]

One more question. Now I have my 1 input wire going to the grid resistors the a res cap combo going to each grid, would I be better off just putting 1 res and cap before the grid resistors or leave it like I have it. My problem was only on my bright vol, I have it were It shuts off all the way now but something with the pot is not working right, Im going to check it out tomorrow.

Thanks
Andy

[Colossal]

Andy,

If you have any photos, they would be very helpful. With a jumpered input arrangement, you should only need one cap and 1M-to-ground on V1a and of course one cap and 1M connected between the two 470k/470k mixing resistors and the V2a grid.

[Andyjoe]

I got it up and going. I went back and touched up all the solder joints and found a broken v1 socket also, it was a bad joint. I think it works very well
I guess that little lag time afer I adjust the pot is normal. Thanks guys

Andy

[KellyBass]

Yep. there's just a bit of lag time after you make the adjustment.

[Andyjoe]

I notice that the more I attenuate my amp I seem to loose a little low end. I have .02 caps on the input and pots would going up to .047 help or should I go higher.

Andy

[UR12]

I notice that the more I attenuate my amp I seem to loose a little low end. I have .02 caps on the input and pots would going up to .047 help or should I go higher.

Andy

You could try that. Maybe even a .1uf. What kind of speakers are you using? Have you tried a different speaker cab?

[Andyjoe]

Im using a green beret and also a red fang 2-12, it's not a lot I just find I have to adjust the eq a little when I turn it down. Now that I fixed my screw ups I really like what it does, but I can never leave well enough allone.

Thanks
Andy

[UR12]

Im using a green beret and also a red fang 2-12, it's not a lot I just find I have to adjust the eq a little when I turn it down. Now that I fixed my screw ups I really like what it does, but I can never leave well enough allone.

Thanks
Andy

Any time you drop the power down low your speaker won't be moving as much air and you have to be able to move some air to produce the bass notes so it's probably normal that you will have to change the eq a little at the lower volumes. The vvr is not an adjustment that you normally will be changing while playing. You should be able to find a setting of the VVR to get the vol level you want and then adjust the eq to get the sound you want at that vol. It should keep the same sustain and distortion characteristics going from high vol to low vol to a point. That point being when the vol is so low the speakers can't move enough air to acurately reproduce the tone any more. Nothing wrong with a little Experimenting and tweaking

[Andyjoe]

Thanks for the info.

Andy