Am I crazy or is it my dac?


Recently my system hasd eveloped a crackling sound in the background when playing tunes thru the Schitt Gungnir Multibit and I'm trying to figure out the source or whether I've just gone nuts

When I first fire up the system, everything sounds fine, then after 30 mins or so when I'm playing music, while the tunes sound fine, a background crackle happens, like a scratchy old recording - though I'm playing files which previously sounded fine.

If I pause play, the sound stops.

Ideas?
Is it the dac? 
Anyone experience something similar?

Thanks in advance,

System
Aurender N100H
Schitt Gungnir Multibit dac
Belles 21a preamp
Primaluna Prologue 7 amps
Martin Logan Ethos 

cdc2

Showing 2 responses by cdc2

Thanks for all the advice. Now for the testing phase to see if:
A.  Is one channel or both
B.  A connection issue
C.  Issue with router being too close to system
D. Dying tube (with 4 power tubes in each to test)
It was in just the left channel.

Turns out it wasn't a tube, but the connects. When I unplugged every connector and power plug from the doc, and replugged them all in. Problem solved.

Now onto to diagnosing the 60 cycle hum from the amp in the right channel.