tabpat
Member
I've been working on this Project One Mark IIIB for weeks now (on and off). Long story short, the protection relay activates on the right channel - mid volume - with or without a load. I have isolated the preamp/amp, swapped amp boards and outputs (left to right), replaced all transistors, all of the zener diodes, checked all resistor values, recapped...literally EVERYTHING. The problem is always in the right channel. The voltage is the same on each amp, the Bias and DC are set to 30ma and hangs around 0mv +/- 2mv. That larger diode right under the relay is the only thing I haven't replaced. There are no markings...and since it's a Project One...there are no schematics. From this board, it goes to the speaker selector and out to the terminals. Any guesses as to a possible substitute?