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VAC Signature 2a Preamp Question

Before you say, "Dude, there's already a thread posted about this question!" Well, forgive me, I could not find it. This is an inquiry for Signature 2a owners who have the built-in MC/MM phono stage: When the selector is on #6, which is the turntable, I get a background hum and some of what is probably tube rush, and it's especially audible with no music playing with the volume up. When I switch to the DAC setting, with the same volume setting, everything is dead quiet. Do I have a problem or is this normal?

Your feedback is welcome and appreciated,
Alón
Ag insider logo xs@2xalonski
knghifi
1,668 posts
 
07-27-15: Maril555
Alonski,
I can save your time and effort- I've had that EXACT same problem, called Kevin, and that's what he advised me to do- move PS away from the control unit. By doing so, you will get rid of 90% of the hum. And that is THE ONLY solution. I even played with some additional shielding with m- metal, no difference.
Maril555, Just curious did you try covering all unused input and output connectors with Cardas or AQ caps?
maril555
619 posts
 
Knghifi,
No, I didn't, but I used shorting plugs, that I feel is a more effective options, than Cardas- made no difference anyhow.
I tried mu-metal sheets to shield PS and control unit- no difference.
Actually, the advice of moving PS and control units farther apart comes from Kevin Hayes himself.
I'm pretty sure he knows what he's talking about giving that advice.
wrm57
1,045 posts
 
I had this problem with my Phi Beta preamp, which is much like the 2a Sig. As others have said, you simply have to move the power supply as far away as possible, at least 3 feet.
Ag insider logo xs@2x
alonski OP
158 posts
 
Gentlemen,
Two issues with moving the power supply out of the rack: first, it looks so darn cool to have all four VAC logos lit up at night while tubes are glowing... (See rack photo on my system page). So, now that I've outed myself as one who cares about the esthetics of my system, not just the sound... Here's the real issue: I have nowhere to hide the PS, unless I stand it on its side between the rack and the couch, something I don't want to do to this beautiful component. No other place is available, and the amps are too heavy to go to higher shelves, so I think for now, if it's indeed a proximity issue, I'll just have hum along with the hum... Thanks everyone for trying to help!

Alón
rcprince
3,071 posts
 
You're right, it really does look cool, that's one of the things I like about my Phi 200 as well. I know it's not as aesthetically pleasing, but could you move one of the amps down off the rack and put it on a lower platform in front of the rack, then put the power supply on the bottom shelf? Otherwise, maybe get a high output cartridge? :^)
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