Hello all!
I am hoping to get some assistance with my Crack + Speedball, that I have just finished.
I first built the basic Crack, and listened to it for the remainder of that day. No problems, so I proceeded to install the Speedball. All voltages are within specifications also after the installation upgrade. There is small discrepancy between A&B sides, which I assume correspond to the left and right channel. My knowledge on the subject is not enough to interpret whether that is meaningful or not.
Small PCB:
OA: 73V
IA: 190V
B-A/B: 0,3 mV
IB: 187V
OB: 70V
Large PCB:
OA: 109V
OB: 110V
G: 0
B+: 188V
The amp makes music, and it sounds great, however there is a problem. After a minute or so of turning on the amp a buzz appears in the left channel, which gets louder as the tubes warm up. It sounds a bit like a fly in the earcup, but not really that loud. Enough to be really noticeable, though. The buzz cuts off every now and then for a split second, and does not change with respect to volume setting. First I changed both tubes, no difference. Next I reflowed all of my connections, except the components on the PCB's. The buzz still persists, and was not altered in any way by the new solders.
Any guidance would be greatly appreciated. I am new to this stuff, and am at a bit of a loss as to what should I try next?
-Tomi