[bluff] What, are you all stupid, isn't it obvious what it means????? [/bluff]
[bluff] What, are you all stupid, isn't it obvious what it means????? [/bluff]
I\'m a street walkin\' cheetah with a handful of napalm..
Hi Steve,
I have only rudimentary knowledge but I'll do my best...
This plot represents the "measurement" of a 11.025kHz tone generated (for want of a better word) at –6dBFS with 16/44,1 resolution as it's reproduced by the D/AC.
The Squeezebox does a fine job at it with a reasonably short and narrow base, no sidebands and low noise floor, unlike the DACmagic when fed by the USB connection which shows visible sidebands (though possibly below the threshold of hearing or of musical program) and the "spike" appears to be a bit wide:
The vertical scale is not the same in both images so the visual comparison is not really that accurate.
I can't however tell you how the lesser performance of the DACmagic correlates with it's sonic performance but it should be responsible for some sort of signature.
I hope this helps.
Cheers,
Ric
- - - Updated - - -
P.S.: For an example of a poor performance try the Zanden 5000 review.
Last edited by tuga; 16-06-2012 at 06:15 PM.
"...man will occasionally stumble over the truth, but usually manages to pick himself up, walk over or around it, and carry on." - Winston Churchill
This is the Weiss DAC202's analog output signal: 11.025kHz at –6dBFS, sampled at 44.1kHz with LSB toggled at 229Hz via AES/EBU and TosLink. 16-bit data cyan and magenta traces...
This jitter output was unmeasurable.
diamond bollocks
just to add in my ha'p'orth, the j test shows - as the rubric states- the effect of the 11 k tone and lsb toggled. This amounts in effect to a 229hz square wave. Thus as with all square waves we see the odd numbered harmonics at 458 hz intervals. These are the magenta lines. Anything else apart from the 11khz line and the 229 hz harmonics is spurious. If you compare the touch - its noise floor via analog out is too high to see more than the top of the 229 hz harmonics. There could be jitter buried in the noise floor.
This illustrates the point that the j test shows Spuria of all sorts not just jitter. aFAIK it is a matter of interpretation to identify which spuriae are jitter related. As for which come from interface jitter, AFAIK this can only be shown by comparing the figures for different inputs. If they are the same for all inputs you may infer that the dac is immune to interface jitter.
Anyway this measures the analog out. No one seems to bother measuring S/PDif out these days. Hence the difficulty of applying figures to the conjecture that tweaks improve the SPDif out.
Sorry, I'm late to this party, but I've just bought a Squeezebox Touch, because I wanted to experiment (and I liked the idea of internet radio). I had some CDs on my laptop and I did a comparison with my Meridian 588, both playing through the same amp and speakers. No difference that I can hear. Now, perhaps the 588 isn't of the same quality as the ones mentioned, in which case I don't want anything better. To my nearly 65 year-old ears, the Squeezebox delivers a very acceptable sound, so perhaps I'll now buy downloads rather then fill up the house with CDs.
The man with the golden ear trumpet
I've also only just come to this thread, and have been reading through bits of it with interest. I had previously thought that my SBT was as good as CD replay using my Arcam DV88, both being connected to my Stello DA220 mkII via co-axial SPDIF cables. Then I swapped my preamp to the Plinius M8 I purchased from a fellow Wammer.
I originally bought a separate DAC after being disappointed by the longevity of the laser in the DV88, and a replacement not being available - I didn't want to spend a lot on an expensive CD-player to have it fail after five years.
Experimentation with "transports" led me to believe that the quality of the input does affect the sound of the DAC. When the DV88 failed, I tried a cheap DVD player as a transport, but buying a Marantz CD5001 for £79 from Richers improved things. Then someone who I'd given an Arcam Alpha on indefinite load returned it, and that was better than the Marantz as a transport. Then I managed to repair the DV88 myself by adapting an IDE DVD-ROM drive, and that sounded better still.
When I initially bought the SBT, I didn't think it sounded as good as the DV88 - it sounded a bit dull and lifeless. Swapping the SPDIF cable and removing the "surge protector" trailing socket (which was causing my phono stage to hum) improved the sound. I also made all the changes computer audiophiles recommend - the software changes to the Touch, streaming WAVs from my NAS, using EAC to rip to FLAC, etc. I was happy that the SBT was as good as CD, and didn't think any more of it.
Then, last week, one of my favourite CDs (at 23-years old) began to skip on a track, so I ripped it with EAC. The "quality" of the rips was 100% for all tracks, apart from the one that skipped, which was 99%. I started listening to the rip, and went back to working on the PC, not really thinking that it would sound any different. It did. The main difference is the bass (which I didn't hear with my previous preamp) - there's more punch, weight and texture with the CD.
Further comparison with other tracks I'd ripped (for the first time since swapping the preamp) showed the CDs to sound better - in most cases with the bass, but the CDs sound more spacious and, well, enjoyable.
Now, I've read "Bad Science", and don't dismiss the idea of expectation, but like other posters, I wasn't expecting a difference - I wasn't even listening for a difference, I just thought I was going to listen to the album without the skipping.
it doesnt matter whether or not you were expecting a difference. your mind expected one..and heard one
Be just and if you can't be just, be arbitrary- William S. Burroughs
I can demonstrate this any day of the week (indeed I have demonstrated it), my Audio Note CDT2/II transport, into an Audio Note DAC, sounds easily and repeatably superior to my SBT playing the same tracks.
I'm not actually that interested in why this is the case (though I suspect it has a lot to do with the PSU and digital output transformer in the CD2/II.
Theorise as much as you like, it's plain as day even to people with no vested interest in the outcome or knowledge of the technologies involved (eg the wife).
The difference between theory and practice is greater in practice than in theory.
Was she doing the dishes at the time? I'm afraid it's not a valid wife benchmark if not.
If you're reading a thread I've created it's probably to do with something breaking or not going to plan again.
The thread's dead, Zed.
Fantastic film
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Isn't it curious how all the ill-mannered posters are on the same side of the debate?
Since my post, I tried swapping the cables connecting the SBT and DVD-player, and also swapping the inputs they use on the DAC. To my mind (see what I did there?), the results were the same - CDs sounded consistently better.
So then, I reset the Squeezebox. I use the Soundcheck mods with the tt -k switch, so I needed to reset it to make any changes. Immediately it sounded better. The only change that doesn't persist after the reset is the one I added from another page to change the priority of the SPDIF process.
My 4 year old son spilled some tomato ketchup on my SBT soon after I purchased it earlier this year. Now I'm not saying that my mind expected this to change the sound, but it certainly did. The overall soundstage is distinctly fruity, and there is a satisfying rich flavour to the overall midrange balance.
This has caused me to further experiment using a variety of sauces and other condiments. Paprika does wonders for Bartok and Kodaly, really spicing up the sound. Reggae Reggae sauce in large quantities really fills out Bob Marley, particularly in the bottom register. Edith Piaf and Charles Trenet benefit from a liberal spreading of garlic butter all over the touch screen.
I'm going to try out placing the SBT in the dust bag of my vacuum cleaner, to see if this cleans up the treble.
I've never had results like this with any CDP.
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My Father had a profound influence on me, he was a lunatic. (Milligan)