Howdy Folks, I am finishing up a build of a 6G3 brownface deluxe, but am having an issue that is vexing me. So I humbly ask the gurus of TDPRI for some input. When using the tremolo, I am hearing some faint distortion that almost sounds as if it’s “behind” the main guitar sound. The more I increase the intensity, the more prevalent it is. I believe this to be blocking distortion of the power tubes. I think the issue is rooted in the common problem that seems to plague almost every brown deluxe: all the voltages are way over written spec. The specified -26V bias voltage was measuring -36V off the bat. I was having some tremolo low frequency thump (the other common 6G3 problem) until I put a diode across the intensity pot. This made the thump 90% better, but it had the side effect of bumping the bias voltage to -42V. I replaced the stock 22K bias resistor with a 20K fixed resistor and a 10K pot. This allows me to dial the grid voltage down to about -38V with proper 6V6 bias, but with the tremolo fully engaged, it can swing to about -62V. Some troubleshooting steps I’ve done: Adjusted the bias Used a variac to lower input voltage down to 110V. Removed the diode on the intensity pot. A slight reduction in distortion, but obviously the thump returns.Added grid stopper resistors. I tried various values from 1.5K up to 5K to no avail Reduced grid leak resistors down to 100K Changed the 100k resistor in the bias supply (tried various values from 100-150K). I’m not sure if this is typically done, but it was a wild idea that I had. With 150K, I could get the grid voltage to -28V. It seems to be improving the distortion some, but it throws the bias of the power tubes off enough that I’m unable to bring them into the correct range. Because my plate voltages were about 445V with a GZ34, I’ve been experimenting with 5U4GB and 5Y3 rectifier tubes in an attempt to get the bias set correctly. Changed speakers and cabinet just for a sanity check Am I on the right track? Am I way off base in thinking that the wild voltage swings of the bias wiggle tremolo are to blame for the issue? What else can be done about it? I can post some pictures or measurements if need be.