Unimind wrote:
ForcedFire wrote:
Are you sure you were set to cathode bias when you had trouble with the VVR? You need a dual gang pot to use a VVR on fixed bias, like the Dana Hall VVR2 or 3.
Well yes I was. But again I am not using the VRM to scale the amp. Just using it to lower the B+ coming off the SS recto before the standby switch. And I should add that this is not a Hall VRM. It's a DIY VVR based on Stephen's VVR.
ForcedFire wrote:
... then stick a big filter cap and bleeder resistor (or 2 in series) to ground between the diodes and the ... standby.
I think that is what I was/am missing. Any thoughts on exact size/values of caps and resistors to use there?
Oh yeah, I overlooked how you were using it. I`m doing the same thing actually but I`m going to add the dual gang pot so I can play with the VVR. I found an old Hammond M-3 organ power transformer on kijiji (Canadian CL) that I`m making a 6V6 Trainwreck express out of and I`m pretty sure I need the VVR to drop the B+.
I know you built your own VVR, I am as well. I was just using the other one as an example of one that tracks the fixed bias voltage at the time as lowering B+.
As for the size of the caps you can go pretty big on the solid state rectifier side. You`re probably limited by space in the chassis. I`m just going close to the old Trainwreck pdf, I bought a couple of radial 150uF 450V caps to put in series on a little board with a parallel bleeder on each cap around 220k 2W.
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