Aphex Channel noise after warming up

[obanta]

Anyway to troubleshoot the power supply without opening it up? The Aphex Channel is plugged into my Furman M-8x^2, so power is conditioned.

[Linuxcooldude]

Might be a ground loop. I've had a simular situation and used a ground loop isolator to remove it. It also could be a volume or gain turned up too high. Any gain that is too high raises the noise floor of electronic noise that is naturally present in all electronic audio equipment.

[Dan Ortego]

For what its worth I've had good results with Aphex customer/tech support.

Jace Nuzback
Product Specialist
APHEX
818-767-2929
jace@aphex.com

[obanta]

Hi Dan,

After not hearing back from techsupport@aphex.com this past week, I tried emailing jace@aphex.com and got a bounce notification back. Can you confirm the email address? Thanks.

[obanta]

If it is ground loop or volume/gain related, would the noise be initially absent and then get noticeable over time without any changes? That's the symptom that is making me think it's internal as the tube and other components warm up. In the event it is a ground loop issue with the symptom I described, which ground loop isolator with XLR connections do you recommend? Thanks.

Dan - thanks for the contact. I'm crossing my fingers that it can be resolved without costly repair.

[mcphillips]

It doesn't sound like a ground loop to me, but it's not impossible. I'd forgotten that it has a tube. That's a possibility, or it could be the power supply. Again, it's hard to tell without being able to play with it in person.

[obanta]

Mike - Okay, thanks. I tried adjusting all the settings I could think of to isolate the issue, including turning the input gain all the way and the noise persisted. The one thing that reduced the noise a little was turning off the BB/EQ/AX.

I opened the chassis and nothing looks bad on the circuit board. I'll contact Aphex and buy a replacement tube to try.

[mcphillips]

I'd ask them about the problem before I ordered a new tube. There could be a known issue with the unit.