manpowre
100+ Head-Fier
- Joined
- Mar 31, 2016
- Posts
- 327
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- 52
I've come across a weird thing with the HA-1. I don't know if it has been discussed here as I left the forum for a long time. I own the Audeze LCD-X and LCD-3 and when I first power up the HA-1 and plug the X in I get a low level hum in the background. Kinda low level buzz. The LCD-3 is 100% quiet.
After about an hour of using the HA-1 and LCD-X it goes away. 100% quiet. As something gets hot it settles down. Anyone else come across this?
I'm now feeding the HA-1 music from Auralic Vega DAC. Just using the amp from the HA-1. The result is glorious.
I dont know if my findings are related, but I looked into the 8khz noise of USB cables, and I played out a mono 8khz clear sound, and on my Oppo HA-1 when it is cold play this 8khz tone clear on right channel. After 30 minutes being turned on, this tone is equal on both sides.
I suspected this to be the 8khz USB noise, so I ordered the Intona USB separator device, and it separates the Oppo from my computer, and it removed the effect entirely.
I did get more punch with the separation filter, so I suspect the Oppo HA-1 DAC is affected by the USB noise. thei high-tones are the same, and actually pretty good on the sabre chip. But USB separation improved soundstage entirely on this unit.
I also bought a new Hegel HD25 DAC, and using that now with the Oppo to amplify for my headphones, and it sounds great. So I am only using the analogue part of the HA-1 now as I found that the digital part was so weak.
Just suggestion, but try to plug in a powered USB 3.0 device between computer and DAC or use optical or the other digital input and see if that appears different. If it does, your issue might be related to USB noise.