Problem with HC audio - right channel dead and humming

[Dan Turner]

Hi - I've got a strange problem with my home cinema set-up and I was hoping for some advice on what might be the problem or how to further trouble-shoot it.

My set-up is a Sony STRDA3300ES AV amp, with the front L&R output via pre-outs to my Naim SuperNait amp, using the latter's AV by-pass mode. I have no centre speaker, the centre channel information is mixed in to the front L&R. The rest of the speakers are Monitor Audio Radius 180 rear speakers and radius 90 backs. Sources are Sky HD and Sony BDPS570 blu-ray.

The problem is that over the last couple of days the right hand front channel has cut-out, leaving a feint hum in it's place. This happens on both Sky and Blu-ray, with both stereo and surround soundtracks.

I've have made sure that the interconnect (a Chord 2 phone to DIN) between the Sony and Naim is in securely, and I've also tried both sources directly in to the SuperNait via digital and there were no problems (and there aren't when playing purely audio sources through the SuperNait).

Any thoughts on what might be the issue, or what further trouble-shooting steps to try?

Help and advice much appreciated!

Cheers

Dan

 

[Andrew Everard]

Suggests either the cable is faulty, or the output from the Sony, although you can't check the particular input you're using on the Naim doesn't have a fault without a known 'good' cable.

Do you have another phonos-to-phonos cable – even a 'free in the box' one from one of your components - you could try from the receiver into one of the Naim's phono inputs? At least that way you could establish whether the problem is in the receiver's output or the phono-to-DIN cable you're currently using..

 

[CnoEvil]

If you swop the pre-outs round, does the problem change to the left speaker?

 

[Andrew Everard]

If you swop the pre-outs round, does the problem change to the left speaker?

Indeed worth a try - just swap the left and right connections on the phono-to-DIN at the receiver end, which should at least tell you whether it's the cable or the receiver's output. If the problem stays on the same channel, it's the cable: if it moves from right to left, it's the receiver output.

 

[Dan Turner]

Thanks for the suggestions chaps.

I think i've managed to narrow it down to the cable. I tried an alternative phono to phono cable and the problem is gone. I guess that means that it either has to be the cable or the DIN socket for the AV input on my SuperNait (hopefully the former).

 

[Dan Turner]

I get dumber, then things get stranger.....I was going to try to prove whether the problem is with the phono to DIN cable, or with the DIN socket on the SuperNait, so I reconnected the interconnect to the L&R pre-out on the AV amp and to a different DIN socket on the SN.

It was the tuner input and I couldn't hear anything at all. Then for some reason I hit the Tape source on the SN and I could hear the AV sound through my speakers - but I hadn't connected the cable to the Tape input.....Then I realised that I could hear the AV sound when I hit the tape source because I have the optical out of my sky box connected to a digital input on the SN which is asigned to the tape input, and that also explains why I couldn't hear anything on the tuner input - another digital input is assigned to that. OK feeling a bit silly now.

So I tried another input - the only one spare was the Aux 2 input, but for some reason the DIN plug wouldn't go in to that socket....not sure if the socket is different, but I did notice that outer band of the plug did have a slight flat spot on one side of it - is it supposed to be completely uniform and circular? Still doesn't explain why it went in to some sockets but not others.

Then I tried the cable back in the original AV socket and....it's now working fine again! I have no idea how or why.

If anyone can make sense of that then further advice is welcome, but I guess I'll just see how it behaves over the next few days.

 

[Andrew Everard]

Aux 2 on the Supernait is a powered input, in that it has a power output for the Naim Stageline phono stage, so yes, different pin arrangement..

Anyway, sounds like the plug had perhaps got a bit loose in the AV socket – glad you got it sorted.

 

[Dan Turner]

Anyway, sounds like the plug had perhaps got a bit loose in the AV socket – glad you got it sorted.

Cheers - that the plug might be loose was the first thing that I thought of and i did wiggle it to ensure it was properly seated and even tightened the locking collar, but that didn't seem to make any difference first time around. But hey, i guess that I can't have done it properly as it seems fine now.

Thanks for the help!