Humming through AUX2 record section

Interestingly, I have just had a similar issue connecting a Revox B215 cassette deck to the AV DIN in/out on my Supernait 3 using a 4x RCA phono to 5 pin DIN.

I called Naim support and he suggested it might have something to do with the earthing arrangement of the Revox. The Revox’s mains socket is two pin.

I then tried the Revox B77 followed by my Nak 680 and both were fine: no hum, so in this case the Revox cassette deck was the guilty party. It’s now talking nicely to the Marantz 2275 in the other system.

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I’ve used plenty of different recorders with my Naim systems - most of the recorders float the earth, some are battery operated, but have never had this issue.

Are you using either the Naim or the Chord 4 x RCA Phono to DIN5 interconnect, or something else?

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Hi Richard, I’m using one I bought from Custom Lynx on eBay. It seems to be pretty decent quality. I think that because it’s fine with the Revox B77 and the Nak deck (which remains hooked up to the SN3), the problem is the earthing set up with the B215. At least it’s happy with the Marantz!

I’m awaiting a new Witchhat cable. Will update when it arrives. Making do with power from the 252 for now

Hi @Richard.Dane

So, I’ve got the new din cable to use between supercap and NAC252 and still get humming.

Feels like the issue is with the Supercap rather than the Superline as I don’t get the issue powering Superline from 252 aux2

Would you agree? If so, I’ll have to box up and send Supercap off for a service

Cheers

Ade

What if you swap the Supercaps around?

I’ve just given this a try @Richard.Dane and the humming persists.

Must point to a Superline issue ? Seems odd as issue not present if powering from 252 ??

What happens to the hum if you change the ground switch setting on the NDX2. I assume you have it set to default (chassis) at the moment ?

Yeah - tried flicking that switch. No difference.

Also tried a couple of resistive plugs. Slightly better but not acceptable

What capacitance plug have you got in ?

I’ve got a 100 resistive plug. Tried a few capacitance plugs. A little better but still not right

My turntable power supply has one earth lead to TT arm and one to back of Superline. I’ve tried a mix of a few combinations which altered the hum a little but not enough.

Weird why it works fine with snaic to 252

Yes that’s a bit strange. One thing that may be worth trying is a standard Naim 4–5 cable in place of the Witchhat version, just to rule that out.

I’m confident it’s not the cable. Didn’t work with din to RCA cable either

I just mentioned the cable as issues have come up before on some systems using the Witchhat 4–5 cable with hum.

One more thing which may be worth trying is powering the Superline from the Supercap socket 1 via a SNAIC5 rather than the Burndy and see how that goes (with Burndy link plug back in on Superline)

Thanks @james_n

I’ve just tried powering the Superline from Supercap as you mention using a SNAIC5 (and still with Witchhat cable) and that’s sorted the hum. I wouldn’t say it was silent but not far off at 10 o’clock.

Must be the Naim Burndy which is almost brand new or some issues with the Superline

Hmmmm

I’m baffled to be honest

Interesting. It does point to an issue with the Superline when powered via the Burndy, particularly as you’ve tried both Supercaps. Might be worth seeing if you can borrow another Superline and Burndy to try out. How old is the Superline ?

@Richard.Dane - I’m sure there was an issue with another Superline which was exhibiting some instability and oscillating when used with a Burndy. I think the factory had seen this before when you checked it out and it needed a bit of fine tuning ?

Yeah - Superline is 2018 which was bought used. I bought the Supercap and Burndy about 18 months ago to use with the Yamaha amp I had it the time. Worked fine then (Supercap used, Burndy brand new).

Superline worked fine when I got the 252 and 2nd Supercap. Weirdly only heard hum previously when the record outputs were unmuted - that’s now changed to the main inputs so something must have deteriorated.

I’ll try stripping down the system and re-build next week. If that doesn’t sort it I’ll have a chat with my dealer

Here’s the thread

Good luck :crossed_fingers:

Thanks - yeah, saw that thread. Think the resolution was a fix for the Superline. Not sure what exactly …. Mine is from the same year of production so might be a known issue

Will update on here how it goes

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Yes, it could well be that James. IIRC the Superline needed to go to the factory for some fine tuning.

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