Peavey Valveking 100 Valve Trouble

[wilzy89]

Hello Community,

First post here. I had a quick search but couldn't shed any light on my problem.

I own a Peavey Valveking 100 which has lately, been doing something strange. After a period of play (anywhere between 1-10 minutes) the volume begins to drop steadily, the sound gets really distorted and the two left power valves start glowing bright red.

The valves in it at the moment are a bit chattery, and are quite old, so I have ordered a whole new set of Tung-Sol pre amp and power valves, in the hope that this will also fix the major problem.

Just wondering if anyone knows what this problem may be caused by.

Thanks

[52 Bill]

After a period of play (anywhere between 1-10 minutes) the volume begins to drop steadily, the sound gets really distorted and the two left power valves start glowing bright red.

Welcome to the place. When output tubes glow red, it's called red plating, because the large metal plate overheats and glows red. This is caused by a loss of bias to the tube or tubes. This could be caused by a bad tube or a problem with the amp's circuitry. Whatever you do turn off the amp as soon as you see this happen, as it can cause damage to the amp's ciruitry.

As a test, try swapping the positions of the left two and the right two power tubes. Now play the amp and watch it to see if the power tubes begin to red plate. Now do the same two tubes red plate or is it the same two sockets? This will show you if the problem is tube related or circuit related.

If you do this test, watch the tubes carefully and be ready to turn off the amp as soon as there is any sign of overheating.

[Enzo]

What Bill said. it could be a loss of bias to the tubesw on that bad side, but way more likely is one of those red hot tubes has failed and is dragging its neighbor down with it. Try new power tubes.