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

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

I have a Reference 3 that was dead quiet for a year using RCA and XLR interconnects. All the sudden one day I got a hum which only occurred when using the CDP.
I replaced the power tubes in the Reference 3 and the hum was gone. As an experiment suggested by my dealer I put the original power tubes back in the Reference 3, using the RCA interconnects the hum was back, switched to the XLR interconnect and the system was dead quiet again. The Reference 3 does that sometimes.

We have come one step closer to the solution. The buzz looks like a mismatch between an high ohm pre-amp (like the ARC) and the impendance of the Kronzilla SXi. We found out by using a Kronzilla DM (monoblock) on the right channel and the SXi on the left channel. No buzz on the DM and an audible buzz on the SXI. Solutions are now being prepared. Will be continued!