Karma docking base RCA out sound quality.

Sorry if this has been discused before, or if it's in a FAQ somewhere.

Anyone else getting extraordinarily crap sound using the RCA outs on the docking base?

I am hearing noise big time. (Interference from the Ethernet and/or USB hardware, perhaps?) It is unusable.

Just strange, given the great sound quality coming out of the stereo mini jack on the Karma itself.

Are you running the RCA's through an amp or just through earphones?

PhilipOHare: Are you running the RCA's through an amp or just through earphones?

An amp. They're plugged into my Yamaha mini system.

These are the same cables I use to plug my Empeg into the mini system. I hear no defects when my Empeg is plugged into my Yamaha via the RCA cables.

Do you have a phono adapter to check if the noise is there with just earphones from the RCAs? That could rule out the docking station.

It is definitely the USB.

Playing classical MP3's that I ripped at 320Kbps, I get noise the instant I plug the USB cable into the docking station. I don't even have to plug it all the way in.

When I remove the cable, the noise stops immediately.

The Ethernet cable produces no noise.

Now I *really* want to ditch the USB cable. Let's get that Ethernet performace up to snuff, Rio.

Incidentally, though not surprisingly, the sound quality coming out of the RCA jacks is still inferior to the stereo mini sound, to my ears. Anyone concur?

When I remove the cable, the noise stops immediately.
The Ethernet cable produces no noise.

You've probably got a good old fashioned ground loop, then. I'll bet that the problem goes away when you unplug the AC adapter as well. There's also a chance the noise would go away if you routed the RCA's into the line-input of your computer's sound card instead of sending them straight to your amp.

Incidentally, though not surprisingly, the sound quality coming out of the RCA jacks is still inferior to the stereo mini sound

According to the signal analyser the RCA outputs have slightly better audio quality than the jack output (at least in terms of SNR).

Rob

Yep, as Tony says - that's a ground loop. Not having to plug USB in all the way is a tell-tale sign - the shield touching is enough to hook the earth of the player into the PC's earth.

Ethernet is isolated (all ethernet devices are) hence doesn't suffer from this way.

The RCA out audio numbers are better than the ones via the headphone out (no distortion from the headphone amp) - maybe it's just a listening preference?

Hugo