Power Help

[Telepathicicepop]

So success in getting the amp to turn on! Stoked. but only halfway.

After letting the amp Warm up, when i switch standby off, it heats up pretty fast, and seems to start red-plating.

I'm not 100% that it is, maybe i'm just being overly cautious.

I haven't taken any voltage measurements yet, mostly due to the fact if it is Red plating, i don't want to leave it running in that state, and cause serious damage.

I've been googling pictures of red plating to see if thats my case exactly.

P.s. I've had several tube amps, including other Marshall's and it seems to be lighting up a lot more tube-wise so...

[Wilder Amplification]

So success in getting the amp to turn on! Stoked. but only halfway.

After letting the amp Warm up, when i switch standby off, it heats up pretty fast, and seems to start red-plating.

I'm not 100% that it is, maybe i'm just being overly cautious.

I haven't taken any voltage measurements yet, mostly due to the fact if it is Red plating, i don't want to leave it running in that state, and cause serious damage.

I've been googling pictures of red plating to see if thats my case exactly.

P.s. I've had several tube amps, including other Marshall's and it seems to be lighting up a lot more tube-wise so...

Check and make sure you have the bias supply grounded and that you have a wire coming off of either one of the two red wires on the PT to the resistor that's just upstream of the bias supply rectifier. Check bias voltage at pin 5 of all your power tubes and make sure you have somewhere in the range of -35 to -45"ish".

Make sure that wire I mentioned from the resistor upstream of the bias diode is connected to the PT side of the standby switch or your bias voltage won't be there when you take it out of standby.

Prior to taking it out of standby, adjust the bias control for the most negative voltage at pin 5 of your power tubes. This will power you up in "cold" mode, then you can adjust your bias from there.

[Alex R]

Run it with the tubes out, that will eliminate the redplating worry.

[Wilder Amplification]

Were you ever able to get everything sorted out?