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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
rrog
1,958 posts
 
Your AC voltage is higher than the voltage at the Audio Research facility. Lower the bias to 60ma as recommended.

This is not something you do by ear.
jazzgene OP
145 posts
 
I went with 60 ma. The music sounds better to me at 60ma as well.

I called ARC. The guy I talked to did not know that VS60 was lowered to 60ma and had to consult a manual. I guess all the older 6550 amps were set to 65ma. So I guess ARC is still sending out the new VS60 set to 65ma.

Anycase, the amp sounds very good.
jazzgene OP
145 posts
 
The transformer on the VS60 buzzes a bit. And the amp puts out a small amount of hum to the speaker. How can I get rid of these noise?
bjesien
1,354 posts
 
I think you should carefully check all of your cable connections. You should not hear any buzzing sounds with this amp. Are all interconnects clean and firmly secured?
jazzgene OP
145 posts
 
The buzzing is from the power transformer. As for the hum in the speaker, I think it is because the transformers are so close to the power tubes. The hum is there with nothing connected on the input. I've also tried lifting ground but the hum remains.

I'm considering PS Audio's Humbuster III. They told me this would stop the buzzing.
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