Lee Jackson Metaltronix Amplifiers

[patiam69]

I have a few questions about this head.

I took the chassis out and there is no hot or burnt spots. Does this head have issues with the molex connectors like the 2 channel heads in your videos. would the hard wire mod be beneficial at this point?

is there a bias adjustment on this head? I see 1 trimmer pot in the area where all the large caps are.

Lastly is a sound the amp would make high pitch screech through the speakers after power down (like 5 or more seconds after switch is shut off), it hasnt done it lately but used to, any adea what would cause that

[shredmuch]

I've had the Molex issue with my 502. I'm guessing the 501s have at least one less preamp tube, since the clean channel uses two separate gain stages than the hot channel. So there may not be as much heater current draw through the connectors. Whether or not to hard wire it is your call I'd say, if it hasn't bothered before.

That trim pot on the "Logic Board" with all the big caps is the bias adjust.

I've had other amps do a delayed pop, hiss, or other noise when shut off, I think it may just be relays or other opto switches deactivating gradually once power is removed.