Hum in ARC Ref 3 not on 0 but 1-103 light buzz


I'm suddenly experiencing a strange phenomena with my ARC Ref 3 (250 hrs on the tubes). On the 0 setting of the volume "dead quiet" with 1-103 a constant sound like the sea whispering noticable on 2 meters from the speakers. Any idea where this comes from? It is from both the two speakers. Tube problem?

Thanks in advance!
broederen
Hello John,

Thanks for your reply,

I've contacted Marek Gencev from Kronzilla. He was very kind to reply me today (27 january)

The situation is getting to its climax. He made me aware of another change I overlooked. At the time I bought the Kronzilla I did not have a Cardas Golden Reference RCA interconnect. I used temporary a Cardas Golden reference XLR cable with Cardas adapters till I got my new Cardas GR RCA cable which I installed during the change in location.

At Marek's suggestion I put this cable back and the HUM looked gone...., but (in these types of situations there is always a but) the "pink noise" (still audible at 1 meter and independent from ARC pre-amp setting) , a part of the HUM was not gone. On this part Marek is still thinking because in another high-end set-up the ARC was dead quiet. But somehowe the Kronzilla SXI have still some "relationship" issues but improving..........

To be continued....

Cheers,

Broederen
There is no way that a change in cable will make that hum disappear. If you believe that, then I have a bridge to sell you here in San Francisco
I'm sorry Oneobgyn, it really works. I quote from the mail from Marek Gencev, chief designer at KRaudio (located in Prague)

Quote mail Marek to me,

start quote:

"I suppose you've told about the hum in speakers, i.e. some kind of 50Hz and its multiple frequencies added to signal way. In your case it is caused most probable by closed ground loop. The Kronzillas SX/SXI are devices with connected signal and chassis grounds. Because your preamplifier is also most probably same and not 'floating' device, the loop appears there. The reason, why SXi and SX has different result, is different topology of inner shielded cables. There are two solutions. You can try to feed your AudioRes. preamplifer through the power cord with disconnected ground terminal or you have to use symetrical cables and symetrical adapter on Kronzilla amplifier side."

stop quote.

It worked out for the HUM (the XLR cable with Cardas adapter on Kronzilla RCA amp input,lifting the ground on the ARC had no inluence) but not for the pink noise on which he later today has returend to me with the following:

start quote

"The preamplifier output stage is most probably too noisy and amplifier sensitivity too high (SXI has 0.75Vrms on all inputs, SX 1V). ""

stop quote

That is the situation till now. To be continued.........

Cheers,

Broederen
Tubes can be imperfect beasts no matter the duration of use on them. It sounds like a bad tube, which will get worse. I would also like to add that I had nordost SPM interconnects running from my power amp to my subwoofer and I was hearing a tremendous amount of hum. I removed the SPM's and connected a pair of audioquest subwoofer cables from the power amp to the subwoofer and it is dead quiet, so through my own personal experience, cables can make a difference! Good luck, Hope you find a solution for your situation.
Well, if the cheater plug failed to relieve the hum, then IMO it is not a ground loop hum