0

I've noticed that I'm losing a lot of high end detail when I plug my soundcard into my hifi amplifier. I use this setup to record and mix music.

The soundcard is an 828mk2. Hifi amp is audiolab 8000a.

There are two obvious differences here - the soundcard outputs are +4db, whereas I believe hifi equipment is -10db. Also soundcard outputs are balanced and I'm using unbalanced cable.

I'd expect the balancing issue to cause RF noise problems rather than lowpassing so I don't think it's that (or am I wrong there)?

Is the level matching issue likely to be the cause of the poor sound quality? I don't want to spend a bunch of money on a level matching box only to find out it makes no difference! Could there be anything else here I should look into before buying a level matching box?

  • Welcome to sound.SE! Note that HiFi questions are off-topic here, but IMO this question could have potential for professional applications too. Perhaps you could rephrase it accordingly? – leftaroundabout Feb 7 '16 at 12:40
  • Hi. Not sure on the rephrasing - I know professional musicians who use hi fi amps for monitoring. I think this question just is applicable to sound design and recording. The fact that it could be applicable to other things too is besides the point. I've done some minimal rephrasing but I'm not quite sure what you're looking for. What I'm using this stuff for has no real bearing on the question or how it could be resolved... – DanBennett Feb 7 '16 at 14:46
1

A balanced line-level output usually has TRS (tip-ring-shield) 1/4" connectors. Connecting them to an unbalanced input requires the use of mono cables which short R with S (ring/return with shield) in the TRS socket.

This balanced->imbalanced conversion works only at the jack level, not at the socket level: a mono socket has only "T" (tip) and "S" (shield) wipers, and the shield wiper will not short R and S (and you better hope that it finds S rather than R or the insulation) of a TRS plug.

So TS sockets want TS plugs while a TRS socket can accommodate either TRS or TS plugs/cables for a balanced/imbalanced connection respectively.

So be sure to use a TS cable with mono connectors. Or a DI box. But with a reasonably short cable, that's sort of pointless.

0

Doesn't seem as though level matching was the issue here (and others off site have confirmed out it would seem unlikely - you'd expect distortion not low-passing from the too-hot +4db signal going into a -10db input) Impedance might be an issue but in this case I have high input impedance, and low output impedance as you'd want.

I tried swapping cables, tried sending signal into other inputs, no dice. Then this morning I unplugged everything, plugged it back in exactly as it was, opened soundcard settings changed them, set them back as they were. At some point in this process the problem fixed itself.

Possibly this was impedance on a line that had been plugged in a long time? Though previous unpluggings hadn't fixed that. Baffling.

So I think probably not a problem with line levels (though that's obviously not an ideal setup), and I don't know what the problem was, but it was resolved by taking my system apart and putting it back together again.

  • Pay close attention to impedance matching and cable length and quality. Simple boo-boos can mess up perfectly good sound even in studio grade equipment. – user18060 May 8 '16 at 0:43
0

You did not reveal exactly what cables you are using. If they are not wired properly, you will get exactly the symptoms you describe. For example leaving half of a balanced line floating will result in a greatly diminished signal (or possibly no signal at all.) No it has nothing to do with "impedance" or "cable length" or even signal levels.

If you fixed the problem by unplugging and re-plugging, then chances are that it was simply a dirty connector pin that got cleaned by the "wiping action" of the connectors mating.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.