USB or S/PDIF DAC?

[jollygreengiant]

Having upgraded my JBL's to a set of Orpheus's from a SNA member, I need to address my source issues. I have decided to stay with a PC music server for now - thus down the DAC path... My SoundBlaster Live card has S/PDIF out and I think the motherboard has onboard as well. Should I get a USB DAC like a KingRex UD-01 or a S/PDIF only like the Lite DAC-AH from coemaudio? I was looking at the SB3 as well, but with a new amp in the pipeline, it will break the bank. Unless we get stimulated again... Any opinions welcomed - the more technical the better as I do not have the luxury to listen to the difference due to location.

[kdoot]

Which Orpheus speakers did you get - the 3's with the newly replaced tweeters that I saw somebody advertising?

What are your priorities in making this DAC decision? Sound quality, convenience, flexibility, price...?

With a computer as a source, you need to be careful to choose a DAC which isn't overly sensitive to jitter (mis-timings in the transmission of the digital data). Since one of the techniques used to reduce the impact of jitter is oversampling, the Lite DAC-AH - a non-oversampling DAC - may not be an ideal choice.

There's no consistent winner between USB and SPDIF in terms of sound quality. They're both capable of delivering bit-accurate CD audio to a DAC, but they're both susceptible to jitter. It's technically possible to build a USB DAC with zero jitter (eg www.usbdacs.com) but that's a high-end product with prices to match. SPDIF can more easily scale to higher resolution music (more bits, more often, for a higher-fidelity sound) but very little music is available to us in high res formats.

The Kingrex UD-01 is probably a reasonable place for you to start, and the 30-day trial offered by Coem is helpful, but to be honest I suspect your speakers are better than that.

Clearly I'm biased towards the gear I bought for myself, but I have to put in a good word for the DacMagic. Street price is about $600. It sounds great, is a good partner for jittery sources and has great flexibility with three selectable sources (one USB, two pairs of optical+coax).

One critical factor in computer-based playback is being certain your computer sends out the original, unmodified music data. On Windows especially you have to take care to avoid sample rate conversion and digital volume adjustments - both of which degrade the sound quality. The same issues exist on Mac and Linux, it's just a bit easier to avoid them.

[likwidsh0k]

One critical factor in computer-based playback is being certain your computer sends out the original, unmodified music data. On Windows especially you have to take care to avoid sample rate conversion and digital volume adjustments - both of which degrade the sound quality. The same issues exist on Mac and Linux, it's just a bit easier to avoid them.

This is one of the main reasons I went the SB3 route. I had already read that for my planned HTPC (with FLACs being the priority) XP media centre is far superior to Vista media centre. Vista has now been scrapped but it did offer bit perfect audio.. unfortunately XP goes through a thing called kmixer and you need to stuff around with ASIO and other drivers to ensure that the audio stream is not compromised. No such probs with the SB3.. and don't have to turn on the tellie to play some tunes.

[proftournesol]

Clearly I'm biased towards the gear I bought for myself, but I have to put in a good word for the DacMagic. Street price is about $600. It sounds great, is a good partner for jittery sources and has great flexibility with three selectable sources (one USB, two pairs of optical+coax).

I'd also put in a good word for the DACMagic as well, certainly in terms of sound for the price, but with one important caveat - it only supports 16/44.1 on USB. That may not be a problem if that's the way all your music is encoded, but if you want to play hi-res 24/96 digital the you have to use SPD/IF or Toslink connections. Don't ask me why CA have done this but it somewhat limits the use of DACMagic for computer based music.

[jollygreengiant]

Which Orpheus speakers did you get - the 3's with the newly replaced tweeters that I saw somebody advertising?

Yes, those are the ones. The decision to go 2nd hand was the right one. I bought them blind or should I say deaf, not having the opportunity to listen beforehand. The improvement between them and the new speakers in the same price range that I listened to, is remarkable. My room helps as well...

What are your priorities in making this DAC decision? Sound quality, convenience, flexibility, price...?

Unfortunately price first priority at this stage, then the convenience and sound quality joint second. Me and the wife share the same system, but with different music, well some overlap...:-) The PC makes it very easy as it is in the room anyway, part of the set-up. My music is 99% flac and hers mix of mp3 and flac :-(.

All my PC's are dual boot winXP and Ubuntu. Tend to use the Window$ "side" more with kx project drivers for the Soundblaster and ASIO as you mentioned likwidsh0k. No up-sampling or anything.

I spent the evening reading far and wide and it seems if the Soundblaster digital out gets a very bad wrap. So I will steer clear of that option. It seems if I am stuck with USB. Read many reviews on the NOS Gigalab Moon and Valab DACs, but difficult to judge the reviewers frame of reference. They might think a Ford is the best car ever made and have never owned a BMW, etc. Oh, now I have put my foot into it hey? Also looked at the upsampling DACs on fleabay in kit form, but no clue at this stage if they are any good. The $ difference between the Kingrex and SB3 is not that big and if it will eliminate sync issues, might be the way forward. What is the result of a sync loss - white noise until re-sync? If that is the case, the DAC will end up in the pool within seconds.

Enough for one night. Love the newly discoverd old hobby.

[kdoot]

I'd also put in a good word for the DACMagic as well, certainly in terms of sound for the price, but with one important caveat - it only supports 16/44.1 on USB. That may not be a problem if that's the way all your music is encoded, but if you want to play hi-res 24/96 digital the you have to use SPD/IF or Toslink connections. Don't ask me why CA have done this but it somewhat limits the use of DACMagic for computer based music.

Actually it does 16/48 via USB, but that doesn't detract from your point.

I'm only guessing, but it's probably so they don't have to write and maintain custom USB drivers. USB has standard "class drivers" for things like audio devices. The DacMagic looks to a computer like a set of USB headphones which support the standard class driver specs... up to 16/48. Going beyond that would require additional drivers as far as I know.

For example... in a similar price/performance class to the DACs the OP was discussing is the M-Audio Transit. It does 24/96 via USB but requires you to install custom drivers in your OS.

Actually that should be one to look at. Ask the guys at Talk To The Mac up there in Cairns if they have one you could listen to.

[kdoot]

Yes, those are the ones. The decision to go 2nd hand was the right one. I bought them blind or should I say deaf, not having the opportunity to listen beforehand. The improvement between them and the new speakers in the same price range that I listened to, is remarkable. My room helps as well...

Very nice! I'm sure you'll enjoy them enormously.

Unfortunately price first priority at this stage, then the convenience and sound quality joint second. Me and the wife share the same system, but with different music, well some overlap...:-) The PC makes it very easy as it is in the room anyway, part of the set-up. My music is 99% flac and hers mix of mp3 and flac :-(.

All my PC's are dual boot winXP and Ubuntu. Tend to use the Window$ "side" more with kx project drivers for the Soundblaster and ASIO as you mentioned likwidsh0k. No up-sampling or anything.

OK, that makes three reasons why I think you should go with SPDIF over USB:

1. Can generally scale to higher-res than USB

2. Completely independent of operating system (no USB drivers required)

3. Future flexibility to connect an SB3, AirPort Express, whatever

You already know about ASIO et al. There's nothing more complicated to deal with.

I spent the evening reading far and wide and it seems if the Soundblaster digital out gets a very bad wrap. So I will steer clear of that option.

Unless it's doing some other kind of bit mangling I don't know how it could be unsatisfactory. And hey, didn't you say your motherboard has optical out too?

It seems if I am stuck with USB. Read many reviews on the NOS Gigalab Moon and Valab DACs, but difficult to judge the reviewers frame of reference. They might think a Ford is the best car ever made and have never owned a BMW, etc. Oh, now I have put my foot into it hey? Also looked at the upsampling DACs on fleabay in kit form, but no clue at this stage if they are any good. The $ difference between the Kingrex and SB3 is not that big and if it will eliminate sync issues, might be the way forward. What is the result of a sync loss - white noise until re-sync? If that is the case, the DAC will end up in the pool within seconds.

Geez I hope you can't buy a DAC that behaves like that. Sync loss should result in total silence. And really, things have to be pretty bad to be losing sync.

Enough for one night. Love the newly discoverd old hobby.

Go on, play something else. You know you want to.