Sound problem help

Posted by: nicky

Sound problem help - 16/11/2006 03:17

When I connect my Rio Central with an optical cable connection, I get occassional intermittent static/crackle noises only on my left speaker.

I've changed receivers, optical cables, speakers, quailty of mp3/wma files and still get the occassional intermittent brief static/crackle/pop like noise from the left side (speaker).

Are others having this problem. Thanks.
Posted by: The Central Guy

Re: Sound problem help - 16/11/2006 14:23

Hi Nicky,
Welcome to the forum.

I've been using the Central for several years now, and have not heard the symptom you are describing. However, I don't use the optical cable nearly as much as the network connection with an attached Rio Receiver.

It sounds like you've covered all the bases by swapping things out, that's what I would try as well.

So how often does the noise/sound occur, and what exactly does it sound like?

Thanks, Randy
Posted by: peter

Re: Sound problem help - 16/11/2006 20:31

Quote:
Are others having this problem.

Yes. I don't know why this wasn't found in the original testing, but it's been reported several times since the Central was discontinued. Perhaps some outboard DACs are more forgiving than others, but for the unlucky ones (including me on my Pioneer optical amp) the Central gives rise to sporadic clicks on the left channel only. No-one's ever investigated the problem fully, but it sounds as if the optical timing is a bit off, and every so often either Central or the DAC just skips one or more samples on the left channel.

Peter
Posted by: nicky

Re: Sound problem help - 16/11/2006 22:06

Thanks for the replies. It sounds like a crackle static pop like you hear on vinyl records sometimes but only on the left side.

Thanks peter for the explaination...although that's disappointng to hear. If anyone have any ideas on ways to fix this (if possible), I would appreciate any thoughts. Thanks.
Posted by: nicky

Re: Sound problem help - 07/03/2007 11:33

If the Rio central is connected thru optical cable, it wouldn't matter if there was anything wrong with the DAC....would it not? Since the digital mp3 is "feed" straight from the source (the Rio hard drive) bypassing the DAC to the optical output as a digital source to the amp?
Posted by: altman

Re: Sound problem help - 28/04/2007 06:54

For DAC, read SPDIF encoder IC....

SPDIF receivers recover the transmitters clock from the signal - plus the clock is an external xtal which is pretty accurate. Not sure what it could be unless maybe the SPDIF transmitter LED is being overdriven or something...?

Hugo
Posted by: tfabris

Re: Sound problem help - 28/04/2007 15:35

I know this is a little late to the thread, but I'm re-reading it...

Nicky, did you ever, at any time, try listening to the same songs played back through regular audio cable instead of the optical connection?

Perhaps it's just a couple of bad rips.

(of course, from what Peter said earlier in the thread, it could very well be an issue with the optical connection.)
Posted by: nicky

Re: Sound problem help - 30/04/2007 07:20

I had a chance to talk to a friend of mine who's an expert on this sort of things and he helped me understand what the problem was.

So for others having the same problem.......he explained to me that when you connect the Rio or any other audio device thru digital connection (ie optical or coaxial cable), the audio device is serving only as a simple transport system. So the Rio is only transporting/moving the pure digital data from its hard drive straight in its digital form, thru the digital cable (ie optical in this case) to an outside receiver/processor to be converted by it's DAC to it's analog form so we can hear the sound.

So, this means there is absolutely nothing wrong with Rios DAC or any other external DAC (since I got the same results using a different receiver). What is wrong with the Rio is that it is not a very good transport system and is making errors and/or interference when feeding the digital data to an outside DAC. In fact he told me people who buy expensive external DAC for music like cds, etc, etc also buy very expensive cd players that doesn't even have DACs so that they can get an accurate error free flow of digital data to their external DAC.

Surprisingly, he was aware of the Rio central when it came out long ago. He suggested to me that the Rio central in the days actually used a very good internal DAC and recommended me to connect to my receiver using analog cables. That way, instead of using the Rio as a transport system and my receiver as the DAC which supposedly has a good Barr DAC, the Rio's DAC will actually convert the digital data to analog and my receiver will just serve as the amp.

Using the analog connection and after listening to hours of music, I have ZERO intermittent/random static-crackle noises. The sound actually sounds different too....better in fact for my preference.

I was always told that digital connection is better than analog, but this is actually VERY wrong and inacurrate from what I have learned. The advantage of digital connection is that you don't get interference (thru cable connections), but what ultimately determines the sound quality is the DAC and amp. And so analog connections can sound much better than digital connections depending on the equipment.
Posted by: tfabris

Re: Sound problem help - 30/04/2007 12:44

What you've said is completely accurate. The crackling problem is, IMHO, a "bug" and shouldn't be normal or expected, but otherwise everything you've said is true.

It's leaving out one important detail, though:

Most of the things that audiophiles would notice about the differences between DACs, and the differences between digital and analog connections in that situation, are very subtle and usually involve very high frequencies. It's these very subtleties that are affected by MP3 lossy data compression. So in the case of the Rio Receiver and Rio Central, it's all more or less moot.