Pyramid Audio

OMG, customer sent this in for warranty repair because the display is stuck on HDMI and the volume Control is stuck at 31. Yes, that is a sticker on the front.

Talk about a blast from the past. early 80s I actually owned one of these . Now I’m working on one.

The signal diodes I chose for the STV-X have more forward drop than the SANKEN version. This was due to space constraints.

This is a great replacement.
But in cases where the current through the bias diode is over 6 mA the bias adjustment pot might not adjust to the correct value.

I have found a more suitable mix of parts to make a better duplicate of the Sanken original.

parts are on order.

I recently did a thermal tracking test from 0 to 80 Celsius comparing my part to the Sanken. Placed in a stirred mineral oil bath, the parts were in series so the current was the same. I tested at 1 and 3 mA. I was pleased to see the voltage drop difference tracked closely. But my part has an almost constant 0.500V higher drop. So changes coming.

Anyone who had problems with the first version can swap for the new one.