Nuforce STA200 issue. Rumble every couple minutes

@dspringham i might have found the issue. 
 

it either doesn’t like my preamp or my subs connected to speaker terminals. 

I went straight from DAC to amp, controlling volume with my Innuos. And turned my REL subs off (they are connected directly to my speakers post along with speaker cables). I never had issues like this with my tube preamp and tube amps. 

gonna test with subs turned on next. Then test back to preamp with no subs. That should test all possibilities and tell me what the Nuforce likes/doesn’t like

Thanks @mesch 

I was just using it as a 3rd amp for when I don't want to burn my tubes 8hrs a day... so I don't really want to build another system around just this amp... it's very good. but with my current configuration is not a very good fit for it, 96db speakers... there's more hiss than I get from my tubes amps.... 

Great amp sound, but not a particular good fit for more all around setup. 

do you guys know of a amp with similar sound characteristics to the STA200 with much lower gain?

Thanks @mrdecibel appreciate the response. I totally get that :)

But for me it's 3rd in line amp, and I'm not going to build a whole system around it, so my tube preamp/amps are first and are staying. My tube pre is only 6db gain, but with that and my high efficiency speakers I can't live with this loud hiss coming from my speakers (which is silent with my tube gear)

It sounds wonderful, so I will move it along to someone that can enjoy it in the right setup, and find a SS amp I can use as a third option that integrates better into my system.