Nuwave Phono Converter, suddenly developed loud background hiss?

Sadly, I think some bad Karma has came my way.

Enjoyed my NPC for just over a year now, love the sound digital facilities but yesterday on switching inputs on my BHK Pre to play vinyl I was hit by a wave of loud background hiss.
Wonderful, :confused: as I’ve just cut back, saved up and invested in a new turntable.
Bad luck indeed.

Tracking the noise down, it was only on the Output with the NPC connected, and was gone when I switched it off.
Yup, hiss was back when it was back on.

Unit is powered by PS Audio AC5 power cord
Connected to my BHK Pre via balanced XLR
Rega P10 turntable has no earth wire, worked perfect before, so no ground wire connected to Unit.

Troubleshooting I have:
Moved the NPC to a different input on the BHK Pre…just the same, the hiss follows the NPC.
Double checked the settings on the Unit, nothing’s changed from before and should be ok.

What I haven’t tried and will try today:
The unit is connected via XLR balanced outs, will try unbalanced RCA’s,
Try different interconnects (Long shot, but unlikely)

Otherwise scratching my head?

I bought the Unit about 14 months ago, and assuming a 1 year Warranty I’m unfortunately just outside it, with no vinyl playback until I can hopefully fix the issue somehow or invest in a new phono stage, which at this point isn’t do-able sadly.

Ah well, no-one lost a leg at least, but sadly no UK traditional enjoying the Christmas “Best of” compilation LPs this year.

Any help/ suggestions much appreciated Guys.


I would not dismiss the xlr cable until you try a different set, you’ll be surprise the many hours I lost trouble shooting issues that ended up to be either cable or connectors

I’ll give that a go thanks.
Being based in the UK I’m not sure what the Guys at Boulder can do for me.

Troubleshooting continues today!

Good luck with testing the cables and wish that it leads to a Merry Christmas

Thanks Chas!
I’ll try the i2s output as well.

Not sure how it compares to the XLR out directly to my BHK Pre, but will see.

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Did you figure it out?

Does the hiss go away when you remove the phono cable?
Have you double checked the grounding wires?

Time for an update, a happy one I think.
Been away from forumland it being Holiday season n such.
So some interesting results after playing with different hookup methods, change of cables n such.

First up I tried the analogue RCA unbalanced outputs into my BHK Pre.
Background noise gone, dead silent, even at full gain settings.
Volume was lower than XLR so bumped up volume on Pre slightly to compensate.
Went back to balanced XLR…loud background hiss.

i2s connection to Dac?
Same as RCA outs to the pre, no background noise dead silent.
Interestingly much preferred analogue outs directly to the BHK pre over the digital connection.
Good to know it works though, first time I tried it!

The issue lies with the XLR balanced outs it seems.
Was dead silent before, no equipment changes or moving wires about…literally next day on switch on the balanced outs produced a lot of background hiss.

Good I have my vinyl playing again, but would prefer balanced XLR directly into my pre like before if possible?
I don’t have the latest firmware on mine (0.54) and I know there’s a later version?

Is there such a thing as a factory reset option or…?
Just all of a sudden seem to be getting this noise from the XLR outputs, wonder if it’s a glitch.
In reality though, aside the +6db gain difference with XLR, are there any real advantages to going balanced to the BHK?
I used a better quality rca to rca than the XLR I was using before, and the sound was richer with better tone…so subjective maybe?

Thanks again.

Tried that XLR cable into a set of active speakers in my 2nd system, there’s distortion on piano that wasn’t there before playing from Optical or RCA.
Only with the XLR connection.
Cable related as someone said before?
What could change in an XLR cable, its like suddenly the Gain/distortion has increased.

Might retry XLR again from the Nuwave, dont have another set of XLRs to hand, but will pick a set up to try.