Thanks for the reply. I did resolve the issue with the Reverb unit that I was experiencing, which was a buzzing of various intensities depending on the setting I used on the Reverb unit. I may have been using some substitute tube types in the unit and also in the amp, and when I returned the tubes in the unit to stock then things improved considerably. I also switched out the tubes in the amp for lower gain, 12ay7 in v1 and 12at7 for the phase inverter and it totally cleaned up the buzzing and funky sounds. I realize the problem could actually be more with the amp and how the current amp components react with the higher gain tubes, but the sound is very good to “primo” that I get now with the stated tubes. I find that the low gain preamp tubes actually allows me to use higher settings on volume, mids and highs than before and this seems to get the amp to a sweet spot under a very playable volume. I’m a harmonica player and prefer a cleaner sound with a bit of crispness, and then some crunch when I overload the mic.