mandrake50
Headphoneus Supremus
- Joined
- Aug 13, 2007
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I think that this buzz/hum is a well known issue with this the SE output into <32ohms. It has been a huge annoyance for me. I own so many headphones that are under 32ohms and I can detect this hum with all of them even in lo gain.The HP's that I use that I can detect this sound with are the Focal Spirit Pro, B&O H6, Phiaton MS500, VModa M100, Cardas EM5813, and Noble Savant. With my 62ohm AKG K712&K702 Annies and MrSpeakers Alpha Dogs no hum detected. Oddly enough I get a completely black background with my 32ohm Grado RS1i. I have a thicker medical grade power cable powering the LC and the buzz does not change with the source being connected or not and becomes more apparent after the LC has warmed up. I get no hum from my Schiit Asgard 2 which cost me substantially less money. So I guess I will just be sure my next headphone will have to be balanced to compliment my Alpha Dog which I purchased specifically for the LC with a Bal. termination. If this hum/buzz issue is something that can be remedied by sending the LC back and paying a fee to correct or lower the amps overall gain; I would gladly do it instantly. CEntrance offered a factory modification on the HiFiM8 Dac/Amp that lowered the overall gain level but allowed for the amp section to be totally black with virtually any impedance. I'm thinking that I will just have to buy the Liquid Spark for my SE low impedance cans/iems and hope that it has a black background.
Are you getting the hum only when driving the LC balanced from your DAC using the SE out? I noticed that I never had any noise or hum when driving the LC SE. I never had any noise using the Balanced output regardless of the input configuration. Beyond that, when I leave the SE inputs connected to the DAC, but select the Balanced inputs, there is no noise on the SE output.
It seems that this is a grounding problem. I believe that the shield/ground connection for the balanced input is not connected to chassis ground. I thought that this could be a cable problem due to anodizing on the shell of the balanced cables that I was using. I got some cables that had shells that are not anodized, but this did not help.
A simple test would be to connect some patch cables from the SE out on your DAC to the SE in on the LC. From my experience this fixes the problem, even if only one RCA to RCA cable is connected.
Even simpler would be to just connect a wire from the shell of the RCA outs on the DAC to the shell of the RCA inputs on the LC. I think just touching the wire on both ends would tell you whether this is a fix. If so, a more permanent solution can be fashioned.
BTW, if you read back in the thread a bit, you will read that this solution has worked for several people. It would be much quicker than hoping for a hardware change that may never come.