Nomad 100 Head...just got it, hum issues...help!

[Aahzz]

Anyone recommend a decent tech in Cincy/Northern KY? I just got a used Mesa Nomad, and man does it hum...I'm still checking on what the seller wants to do, but if I'm stuck, I need it taken care of...hums with nothing plugged in at all, increases with volume turned up, and picks up radio stations when the output is cranked...so far, it seems completely independent of preamp settings/channel. I've swapped the V1 with a known good 12ax7, but that's about it so far....

Recommendations?

Thanks!

 

[Aahzz]

So poking around in other threads, I tried removing the phase inverter - and that makes the hum go away...methodical preamp tube replacement is coming next....

 

[Nomad100]

Curious if you can get this to happen on all channels, or does it just happen when using the higher gain modes?

I have a Nomad 100, doesn't hum that much at all. It was kind of noisy with older (actually really bad) preamp tubes.

 

[Aahzz]

AH-HAH!!!!

Played around more with the tubes - I picked up a couple Sovteks this morning, and decided to try them in place of the JJ's the seller had recently put in. With a sovtek in V1, and in the phase inverter, I'm down to the normal, slight hum one expects from a tube amp near a computer. Yay!

Nomad 100 - there was a base, loud hum on all channels - for some odd reason, it was affected by the master on channels 1 and 3, but stayed steady on channel 2.