A few months ago I purchased a 74 100 watt MkII with 6550's in which I intended to install a PPIMV. A previous owner must have had one installed at one time because there was a hole already drilled in the front panel next to the on/off switch and some non-factory solder joints on the PI coupling caps. The other odd thing was a few resistors were values for EL34's not 6550's. I swapped those out and purchased a pre-wired PPIMV for 6550's off ebay and installed it. I made a pretty big mistake and initially soldered one of the wires from the dual pot to the wrong end of where the bias resistors were (circuit board and I got confused
), when I turned the amp on, I heard what sounded like glass clinking through the speakers for a few seconds then the fuse blew. Realized the mistake I made, fixed it and hoped for the best... Everything came on a seemed to work and sound just fine, except for when I turn the PPIMV up to around 6 o'clock, that's as loud as it gets, and eventually when I try to turn it all the way up to 10, the volume goes all the way off. Not sure if my error caused this issue or where I should begin to investigate whats causing it, any guidance would be greatly appreciated.
Thanks,
Rich