The light bulb limiter thing

[crianlarich]

What do you think: will it work with hybrid amps?

Such as my Music Man. Haven't plugged her in for ten years. Was squealing then, uncontrollably at least in "High"-Mode.

[46346]

sure, if you mean using a 120v light bulb on the AC line in, it's not just for tube amps. i've used it on higher voltage solid state gear as well. i would expect it to work properly on my MM amp, i believe it's a HD 130. it should detect any significant shorts, mis-wirings, etc. just be ready at the switch if the bulb burns brightly for more than one or two seconds. it will normally burn brightly for only a flash, before settling down. cheerio!

[46346]

What do you think: will it work with hybrid amps?

Such as my Music Man. Haven't plugged her in for ten years. Was squealing then, uncontrollably at least in "High"-Mode.

funny, my MM HD130 started squealing in Hi Power mode. playing Bass. sounds fine in Low.
i'm pretty sure Low Power only uses two of the four EL34's, and that's how i always liked it.
so i haven't bothered looking into it yet. my guess was that one of the power tubes has gone microphonic or is failing.
i'm curious of you learn anything!

cheers.

[crianlarich]

Thanks a lot for your replies!
Power mode in amps like mine is achieved through different plate voltage. Which is over 700 Volts in "high" mode! This makes me reluctant to deal with it at all. Amp needs to go no matter what.
So options for listing it are

1) letting a tech sort out the problems first
2) checking (with all safety measures I can come up with) if it runs in "Lo" mode, offering as project
3) doing nothing, offering as broken

not sure if 1) would be viable economically as buyers like to fix things (but MusicMans are tough!!) and pay a good price regardless.
Tubes were replaced and power section repaired in '95 (radio technician), they don't have many hours on them, as I started using a nice little Dynacord shortly after. Off course electrolytics should be critical.

[andy_tchp]

I feel like a fully serviced/repaired amp with a clean bill of health from a reputable tech is an easier sale than something that's obviously not working at 100% for unknown reasons, which leads to buyer unease and low-ball offers.