digger945 Posted October 11, 2009 Report Share Posted October 11, 2009 Ah, I just seem to always associate I2S with RJ45. And in case anyone is interested, someone has written a review here comparing the more popular converters in the market. Am I correct that the only DAC he used in this review was the Audio-GD DAC-19MK3? ...and is the hiface thing the ultimate winner. BTW, did anyone read the 6 moons review of the U2 ? What, you don' like purple? I like purple lots. Funny. I just snagged a Parasound 2k on Agon and the first thing the dude asked me was "do you have a good digital cable?" Quote Link to comment Share on other sites More sharing options...
Upstateguy Posted October 12, 2009 Report Share Posted October 12, 2009 What appears to be a RJ45 on North star MKII Quote Link to comment Share on other sites More sharing options...
K3cT Posted October 12, 2009 Report Share Posted October 12, 2009 @digger945 Yes but I'm more concerned on how everytime the reviewer acquired a new converter, he would prefer the newer unit to his older one. This is a bit disconcerting. @Upstateguy Am I correct to assume that your standard Ethernet cable can be plugged between such port in the DAC to a converter unit like the Teralink-X? Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted October 12, 2009 Report Share Posted October 12, 2009 hopefully that's not a webserver out Quote Link to comment Share on other sites More sharing options...
Currawong Posted October 13, 2009 Report Share Posted October 13, 2009 I recall something somewhere about the Northstar pinout for the I2S being the reverse of normal, whatever that is. The PCLinkII is the TeraDak without the DAC, isn't it? That's what I was using for a while anyway. I really would like to see all this gear measured for jitter and whatnot by someone with some serious gear who knows what they are doing. Maybe Canjam 2010 needs a Sound Science table manned in such a way? Quote Link to comment Share on other sites More sharing options...
morphsci Posted October 13, 2009 Report Share Posted October 13, 2009 ... Maybe Canjam 2010 needs a Sound Science table manned in such a way? Hmmm .... Interesting idea. Quote Link to comment Share on other sites More sharing options...
Hopstretch Posted October 13, 2009 Author Report Share Posted October 13, 2009 Jitter measurements are a can of worms inside an even bigger can of worms. There was a thread on AA that had some good manufacturer anecdotes before it went South and devolved into an asynchronous/adaptive pissing match. I'll dig up the link when I get home. Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted October 13, 2009 Report Share Posted October 13, 2009 Hmmm .... Interesting idea. oooh, get Headroom to bring their AP box and I'll man the table. Then, see what you can do to get me a few of Ray's portables to test Quote Link to comment Share on other sites More sharing options...
spritzer Posted October 13, 2009 Report Share Posted October 13, 2009 I'll deal with Ray while somebody swipes the amps. Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted October 13, 2009 Report Share Posted October 13, 2009 I'd had this idea for some time. I think in the next couple years or so, I'll just buy my own AP. Perhaps I would be willing to offer a service where you send me your amplifier and I measure it... useful to separate the wheat from the crap DIY builders (and more than a few commercial entities as well, I'd guess)... Obviously I wouldn't be able to go for one of the current models, but the System One might dip down into my territory. Quote Link to comment Share on other sites More sharing options...
morphsci Posted October 13, 2009 Report Share Posted October 13, 2009 If you know anybody with a SYS-2720 or SYS-2722, have them give me a call and we'll talk. Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted October 13, 2009 Report Share Posted October 13, 2009 If you know anybody with a SYS-2720 or SYS-2722, have them give me a call and we'll talk. ehhh, Headroom? Quote Link to comment Share on other sites More sharing options...
morphsci Posted October 13, 2009 Report Share Posted October 13, 2009 OK, someone not a vendor, for obvious reasons. Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted October 13, 2009 Report Share Posted October 13, 2009 OK, someone not a vendor, for obvious reasons. Can we tell Dinny it's a DAC and get him to buy one? Quote Link to comment Share on other sites More sharing options...
spritzer Posted October 13, 2009 Report Share Posted October 13, 2009 How about we get Tyll drunk and "lease it" though a dummy corporation? Quote Link to comment Share on other sites More sharing options...
Hopstretch Posted October 13, 2009 Author Report Share Posted October 13, 2009 Can we tell Dinny it's a DAC and get him to buy one? He wouldn't keep it long enough to make it worthwhile. Quote Link to comment Share on other sites More sharing options...
NekoAudio Posted October 14, 2009 Report Share Posted October 14, 2009 I'd had this idea for some time. I think in the next couple years or so, I'll just buy my own AP. Prism Sound is another alternative, in case you start looking. Quote Link to comment Share on other sites More sharing options...
The Monkey Posted October 14, 2009 Report Share Posted October 14, 2009 I only want things with lights. Quote Link to comment Share on other sites More sharing options...
Currawong Posted October 14, 2009 Report Share Posted October 14, 2009 I'm entirely for the anarchy it will create if random people rock up and get their stuff measured, then the whole thing is posted on HF. This mainly because there are too (two? ) many people waking pseudo science in the Sound Science forum (Sound Pseudo Science forum?) and I want them to shut the fuck up. I noticed, btw, JayDee posted measurements of the SonicWeld Converter, which were suitably impressive, if not comprehensive. Can't be bothered finding the link though, it's in the review thread I think from about 3 or 4 days ago. Quote Link to comment Share on other sites More sharing options...
K3cT Posted October 14, 2009 Report Share Posted October 14, 2009 He doesn't mention about any variance in the measurement graphs though so it's pretty much garbage for me. Quote Link to comment Share on other sites More sharing options...
manaox2 Posted October 14, 2009 Report Share Posted October 14, 2009 I noticed, btw, JayDee posted measurements of the SonicWeld Converter, which were suitably impressive, if not comprehensive. Can't be bothered finding the link though, it's in the review thread I think from about 3 or 4 days ago. I didn't see anything after reading all of his posts. I did see that he measured the ripple and such of some USB buses in response to measurements of the m2tech hiface, but nothing about his own device still. Quote Link to comment Share on other sites More sharing options...
morphsci Posted October 14, 2009 Report Share Posted October 14, 2009 I am seriously considering setting something like this up at CanJam'10. I think setting it up to measure jitter will be an "enlightening" experience for some people. I also want to try to preemptively remove the excuses and thus am looking to not have any direct vendor involvement. Stay tuned ... Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted October 14, 2009 Report Share Posted October 14, 2009 I also want to try to preemptively remove the excuses and thus am looking to not have any direct vendor involvement Quote Link to comment Share on other sites More sharing options...
Hopstretch Posted October 14, 2009 Author Report Share Posted October 14, 2009 (edited) Jim, I think you'll find setting up any kind of accurate jitter measurement apparatus and methodology will be a lot harder than it sounds. Unless you have $30,000 lying around for an AP-2722. John Atkinson neatly summarized the state of play earlier this year in Stereophile here. And here's a bit from Charles Hansen about interpreting the numbers produced by the tests commonly in use. Hi-Fi News's current editor is Paul Miller. Several years ago he was selling an audio test set based around a National Instruments computer acquisition card. It would do a lot of things, including a jitter test. However, the jitter test results from this machine are problematic at best. There are two huge problems with this methodology: a) The acquisition equipment must be better than the device under test. The original set used a 16-bit card, and was later changed to a 24-bit card. Stereophile used the 16-bit card for many years. Hi-Fi News uses the newer 24-bit card. Now Stereophile uses an Audio Precision 2722 to measure the jitter spectrum. Of all of these test setups, only Stereophile's measurements with the latest and greatest AP don't exhibit spurious noise and false peaks from the test equipment itself. That is why JA did a (web-only, unfortunately) compilation of all of the DACs and players he has measured since acquiring the AP. The measurements found in Hi-Fi News are not as reliable as Stereophile's current measurements. The test used is one devised by Julian Dunn many years ago to test the S/PDIF interface. It is not particularly useful for testing one-box disc players or other devices (such as an asynchronous USB DAC or an Ethernet DAC like the Squeezebox) where the master clock is in the box with the DAC chip. Dunn's original proposal was to use a 24-bit test signal, and he dubbed this the JTEST signal. The problem is that a CD player can't play a 24-bit signal, so people started using a 16-bit JTEST-like signal. The measurement limit of the 16-bit signal is around 120 psec. A good player will measure around that number IF the test equipment is good enough to not add any other garbage to the results. The theoretical measurement limit of the 24-bit JTEST signal is another 8 bits lower, or around 2.5 psec. So you have to be *extremely careful* when comparing jitter numbers. So, say, 60 psec *with the 24-bit signal* is NOT very good. And then there's this, which I've read several times and only succeeded in consistently making my head hurt. AES: Specifying The Jitter Performance Of Audio Components. Godspeed! Edited October 14, 2009 by Dusty Chalk Quote Link to comment Share on other sites More sharing options...
Elephas Posted October 14, 2009 Report Share Posted October 14, 2009 Why do people want to muck around with USB converters or USB DACs? Dedicated PC for audio > RME HDSPe AES (slaved to master clock generator) RME drivers are very good and work OK with WinXP, Vista, Windows 7, and Mac OS X. Quote Link to comment Share on other sites More sharing options...
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