[johncrooks]

My new Audio by Van Alstine FET VALVE 550 amp HUMS badly(inside case-not thru speakers) when powerd up via a solid state relay. 12V control power to relay from Bryston 4Bsst via Bryston BP-25 preamp, SSR=  Potter & Brumfield SSRT-240D10.  This remote power arrangement works fine with a vintage Solid State amp recently replaced by the AVA amp.

Am looking for a way low cost way to power up the 2nd amp(550) from the 12v source from the 1st (4BssT) amp.  The output voltage from the SSR is 118V +/- 0.2V. 

Is there something about the FET-VALVE 550 that doesn't like this power situation?

thanks

[TomW16]

The only thing that comes to mind is that the AVA amp doesn't have a 3-way grounding plug.  I wonder if the 12V relay is somehow introducing some noise into the AVA amp? 

You could post in the AVA forum here on Audio Circle and Frank might personally be able to help you out.

Good luck.  It's a nice amp.

Cheers,
Tom

[JoshK]

It sounds like the relay is causing a ground loop problem in your arrangement.  These are simple problems but hard to trace down.  Once tracked down they are very easy to fix/alleviate and it doesn't mean anything is wrong with the components.  My best advice is to contact Frank and explain your situation and have him help you find and tackle the problem. 

[lectraplayer]

Wouldn't ground loops and noise come out through the speaker?  It sounds like there are tubes and/or wires vibrating according to the original explanation.

[JoshK]

Yes, your right.  I didn't read close enough.   

Still your best bet is to contact Frank.