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ARC VS60 bias

I just rec'd my new ARC VS60 amp and I think it sounds quite good out of the box. The document says the burn in period is like 600hours!

My question is the bias. The amp out of the box shows 65ma. The manual says 60ma. This is my 1st tube stereo amp so I am looking for veterans advice on where to set it. I suppose the tubes will last a bit longer at 60ma and I should use my ear to judge...
jazzgene
cmalak
681 posts
 
Jazzgene...that should not happen at all. Did you call ARC? If you bought this through an authorized dealer, you should be able to get the unit replaced or fixed so that there is no hum.
bjesien
1,413 posts
 
What is the efficiency of your speakers? I've used similar ARC amps with 87-94 db speakers and never had humming and buzzing except when it was in the music or connections were bad.
jazzgene OP
145 posts
 
I have called ARC. Waiting for Calvin to call me back.

The efficiency of the speaker is 91db. It's Focal 1027 Be pair.

The amp is brand spanking new from a dealer here in the NYC area.

Cmalak - are you saying that this amp should be dead quiet in the speaker with no hum?
jazzgene OP
145 posts
 
Spoke with ARC. They say the slight hum in the speaker is normal for this amp. However, the published spec states 0.2mVAC with inputs shorted.

I checked it out and the left channel shows 0.7mVAC and the right channel shows 0.25mVAC. I'll have to get to the bottom of this. A new amp shouldn't have nearly 3x more hum in one channel than the other.
bjesien
1,413 posts
 
Have you swapped tubes from one side to the other?
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