Sunday, April 19, 2015

Vibro Champ now running

Completed amp
Over the past couple of weeks I have tried to eliminate the HF oscillation that I have been getting from this amp. Taking my Dad's advice I removed the feedback loop.  This eliminated the problem completely.  The amp is now quite.  I am still experimenting with the two different power tubes that I have wired this amp to accomodate:  7C5 and 6V6.  Everything seems to work but I will check the voltages to see if anything is out of range.  Top photo is the complete amp minus the cab.  Second photo is the bare chassis after stamping of letters and numbers.  I also buffed with wire brush.  Bottom image is the schematic as things are at this point.  Not shown is the 7C5 socket wired in parallel with the 6V6
Chassis after letter stamping

schematic showing feedback removal