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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
zd542
5,339 posts
 
It could be a few different things, but I think the most likely cause would be that you have too much gain on your phono section. If you're using a high output MC cartridge, you need to use the MM setting. Its a common mistake. Other than that, you really need to list your entire system.
zd542
5,339 posts
 
If you're not 100% sure, try the MM setting regardless. You can't damage your system in any way. You're essentially lowering the volume, so don't be afraid to try it.
dweller's avatar
dweller
3,781 posts
 
Is there any other equipment above or below (in close proximity)to the phono board? If so move it/them away and hear what happens (after doing Zd542's excellent suggestion, of course).
rcprince
3,071 posts
 
Adding to Dweller's comment, is the control section of the preamp sitting on top of or close to the power supply?
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
The phono stage uses additional tubes plus the line stage tubes. So you could have more tube noise. That said, did you buy new, or a used unit? How many hours on the 6 12AX7 phono tubes?

I would contact VAC, Kevin and Brent have always been very helpful and responsive to my queries.
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