[Airwolf]

I was wondering if Questyle is out of business. I have a CMA 400i DAC/AMP and it has a very audible hum coming out of the left channel of the balanced XLR output. I am not sure if it is also coming out of the 2.5mm or 6.35mm outputs, as I do not have one of these cables for my HD-650's and my other headphones are currently packed away. Either way, I have tried different plugs in the house, installed a Furman SS6B power conditioner, and a different USB audio source. I have sent 3 emails over the course of about 3 months to Questyle about this issue and have not received any responses. I am not able to call their number in China as I do not have the means to dial international numbers with my cell phone provider.

Any suggestions would be appreciated. This DAC was expensive and I would rather get it fixed than just buy something else.

 

[Mightygrey]

I've tried getting in touch a couple of times in the past couple of years over a faulty USB input in my CMA600i - I've never had a reply. I'd suggest looking up their local distributor in your country. If you're in North America, it's Bluebird Music.