[JEaton]

Once I ripped the remastered CD and streamed this from the SB, I could hear no differences between that and the original CD playing on the Sony.

I hope that made sense.

I don't quite follow, either.  What exactly were you playing through the SB prior to this (when you say it sounded inferior to the CDP)?

[jsalk]

Once I ripped the remastered CD and streamed this from the SB, I could hear no differences between that and the original CD playing on the Sony.

I hope that made sense.

I don't quite follow, either.  What exactly were you playing through the SB prior to this (when you say it sounded inferior to the CDP)?

It was a version of the CD that had been ripped to my Slimserver system earlier.  It was not the "re-mastered" version of the same CD I was playing.  Once I ripped the re-mastered version and played that through the SB, I could not hear a difference between the two.

- Jim

[jsalk]

Maybe Jim's system is not resolving enough to hear any differences? 

Kris -

Entirely possible, but I have my doubts.  I was driving SongTowers with the ribbon tweeter and they do a pretty good job resolving a lot of detail.

At some point I will try various source units with one of Frank's DAC's, a good amp and a pair of HT4's (or whatever they will be called).  Then there should be no doubt as to the outcome.  Until then, I'll just have to wait to draw any firm conclusions.

- Jim

[Wayne1]

To sum up, I would still like to understand what differences in various digital sources fed to the same DAC would result in clearly audible differences

Jim,

The differences in the power supplies in each source would play into a lot of what you end up hearing. Mike Galusha touched on this in his earlier post. The SP/DIF signal to the DAC is an analog signal (square waves) at RF frequencies. The 1 is a signal to a chip to go high, the zero to go low. The voltage swing is usually 3.3 volts. Where does this come from? The power supply. How fast the voltage goes from low state to high is dependent on the power supply. How well damped the power supply (type and size of capacitors used) is will determine if there is ringing of the signal. All of these things will determine the sound of the SP/DIF. If switching power supplies are used, as in most inexpensive transports, the switching noise will be sitting on the voltage that feeds the chips. This can sometimes cause false readings.

Other things are touched on in the excellent thread by Pat of ART. Mike again mentioned some of them. The transmission line used to connect the transport to the DAC is usually quite different from product to product. There is rarely a true 75 ohm connector used. The traces on the circuit board and the components used are usually not designed with RF signals in mind.

If you guys are able to get a "clean" digital feed out of one, then maybe I am doing something wrong. Any suggestions?

One of the things I always suggest to new users of the SB is to try out a linear power supply. You do not have to spend $1000.00 on one to be able to hear a difference. As I mention above the SP/DIF signal is directly dependent on the quality of the power supply. If you are using a power supply that injects noise into the DC lines, your digital output will not be able to send out the proper waveforms to be changed into music. The SqueezeBox  3 does also have internal switching power supplies that add more noise to the lines, but by supplying the unit with clean power to begin with, the noise will be that much less.

There are other things that can be done internally to the SB that can improve the signal, but here is not the place to discuss them. Come on over the the BOLDER Cable Circle and I will be happy to go into detail about them.

There are also many reasons why some people hear "major" differences in power supplies and others don't hear any change. A good look at what is plugged into your AC line can be revealing. Are any cell phone chargers nearby? How about a laptop or desktop computer? DVD Player? TV? All of these things use switching power supplies. They are always on. The power supply is always spewing nasties into AC line raising the noise level. Unplug as much as possible in your room and house and take a listen. You might be surprised how much better your system will sound.

[oneinthepipe]

Maybe Jim's system is not resolving enough to hear any differences? 

Kris -

Entirely possible, but I have my doubts.  I was driving SongTowers with the ribbon tweeter and they do a pretty good job resolving a lot of detail.

At some point I will try various source units with one of Frank's DAC's, a good amp and a pair of HT4's (or whatever they will be called).  Then there should be no doubt as to the outcome.  Until then, I'll just have to wait to draw any firm conclusions.

- Jim

Don't forget the preamp.  I think the preamp has as much influence on a system's detail as the amplifier. I have a complete, sans source, AVA/Salk system, and I think that the system is very detailed/resolving/revealing.  When my preamp was with Frank for an upgrade, I used a substitute preamp, and some of the little sounds that I heard previously in the music lacked detail or were missing completely.

[Wayner]

In my new MusicDirect catalog they have a new USB to DAC converter for $99. I think it's called the Streamer, but I can't find the damn catalog now. I think this thing just converts what ever music file that can be sent down a USB cable to analog. Anyone else see this thing?

Wayner

[Charles Calkins]

Wayner:

 The latest issue of The Absolute sound has a very informative article on USB DAC's. Overall they think that none of them performs as good as an S/PIDF DAC. On the other hand they were quite impressed with The Streamer and The Streamer+. Hope this help

                                          Cheers
                                         Charlie
                                     
                                                   

[zybar]

Wayner:

 The latest issue of The Absolute sound has a very informative article on USB DAC's. Overall they think that none of them performs as good as an S/PIDF DAC. On the other hand they were quite impressed with The Streamer and The Streamer+. Hope this help

                                          Cheers
                                         Charlie
                                     
                                                 

Charlie,

What USB DAC's do they discuss?

I am hearing very good things about the new Ayre USB DAC, as well as the Wavelength Cosecant USB DAC.

George

[Charles Calkins]

George:

 Nothing very expensive. Just run of the mill affordable  USB DAC's. The top end DAC's were the Bryston and The new ARC DAC-7 The ARC was the best but still not as good as S/PDIF.

 I gave my Magazine to Rashiki so he could read the article. Otherwise I'd give you a complete list of the DAC's they tested.

                                                 Cheers
                                                  Charlie

[ted_b]

The new TAS's USB article/primer is significantly flawed to the point of being a joke.  The whole industry is talking about how poorly it is done.  Gordon (Wavelength) and Charles (Ayre) pulled out and asked not to be included, and of course, theirs are two of the best USB DACs out there (asynchronous USB communication, low jitter, apodizing MP filters, etc.).  SP/DIF is a well-known jitter causing agent, and the article spends no time digging into the details.  thw riter stated he was trying to dumb it down for his audience, non-technical ATS readers.  huh?  Anybody reading about computer audio is likely technical enough to absorb some truths, and needs to know what the trends are...which are all about reducing the jitter, creatig a stable platform, and creating advanced digital filters like the apodizing ones that Ayre, Berkeley, PS Audi and others are now using.  It's a shame that TAS has missed this one so badly.  The author/writer even pointed out that their are no audiophile firewire DACs right now (huh? can you spell Weiss) yet the Weiss Medea (and Jason transport) are reviewed glowingly (by another writer) in the same magazine a few pages down!!

BTW, Stereophile has a good review on Gordon's Cosecant DAC, and I'm demoing it and the Ayre right now.   Very nice.    i demo'd the Bryston, too, and I wouldn't call it a USB DAC.  It's BNC and AES/EBU inputs are much much better, and elsewhere in TAS's evaluation it is pointed out. 

[rydenfan]

I agree with everything Ted said. That TAS article is an absolute joke. I was literally talking out loud to myself while reading it I was so frustrated with the "review." Ted also received an email from me blasting it in my frustration  I cannot believe with how important computer based audio is becoming in this hobby that TAS could allow such trash and inaccuracies to be published. Just my $.02

[mr_bill]

I would be very interested if anyone has any findings on whether there is a difference using a CD Transport or Duet or Transporter to feed signals to a high quality external dac.

What do you mean by findings?

Myself and others have already posted our opinions on this topic over the last few years here on AC.

Clearly I am in the camp that feels a computer can offer superior transport abilities when feeding an external DAC (which can include a Duet, Transporter, USB DAC's, etc...).

George

I don't think I stated that correctly.  What I was after is the audible difference between using the Duet versus the Transporter as 'transport' only into a high quality external dac.  I wasn't trying to bring up the debate of using a streamer versus a cd transport. 
Kobbi's answer was helpful.

[nyc_paramedic]

dupe...

[nyc_paramedic]

Anyone here use a squeezebox with a Mac or PC? If I'm not mistaken, you install a program on your computer and it simply streams from your computer, it doesn't actually hold the files itself. If I'm not mistaken, someone said Jim demos hooked up to a squeezebox, but I have to wonder if he brings a computer along or has some nifty setup.

I'm trying to figure out the best way to get my songs across the room into an Insight preamp. Can you run a squeezebox off of iTunes or do you have to use their separate music server?

I'm going to quote the original poster as I noticed that the thread wandered a bit but covered relevant topics. If the OP (or anyone else who engaged in this discussion) is technically inclined might consider try using Linux.

There are several advantages:

-No ASIO or other Windows-centric mixer issues.
-The ability to have a stripped down system (no GUI or superfluous services) running on simple hardware.
-Open source GNU software; you have full access to source code and developers; are not bound by "proprietary" software; can custom tailor the system to your needs.
-Cost. Can be cheaper than most "audiophile" solutions.

I have been running a custom made Linux music server for almost two years with spectacular results. It's a bit different from what has been normally seen on the usual forums, as the server is running on small x86 single board computer. No VGA, keyboard, fans, ATX switching supplies, on board sound, etc. My particular board has power, ethernet, and USB, and a couple of programmable staus LEDs.

And getting more technical, what we have is...

A small (6"x6") PC Engines ALIX single board computer running Voyage Linux off of a compact flash card. The entire OS runs in RAM. Voyage, being based on Debian Linux,  was designed for for small SBC's (single board computers) such as the ALIX while retaining Debian's apt package manager. Apt makes the actual installation on embedded devices so much easier.
 

The music is played with MPD, aka music player daemon. It's a music player designed on the server/client model. The MPD server runs on the (headless) ALIX, and the clients that control music playback are run on other machine or devices, e.g., I have a Nokia N800 as a remote for MPD. MPD supports a wide range of audio files including FLAC's. Audio can be buffered entirely into RAM before playback. I also use the standard USB audio kernel driver and ALSA --with no mixers in the audio path-- to drive a Wavelength Audio Brick V2 DAC.

There are also clients for Apple's iPhone and iPod touch, Google's Android, Nokia Internet tablets, standard Linux machines, Windows, Macs, and even blue-tooth phones.



More details here:

http://cheap-silent-usb-linux-music-server.blogspot.com/

http://www.head-fi.org/forums/f46/my-new-3-watt-dead-silent-usb-linux-music-server-pics-added-326831/

[BrianM]

A significant number of audiophiles are running tube amps. Is it unreasonable to suppose that the distortion characteristics associated with vacuum tubes would likely mask whatever subtle improvements had been made in the digital transmission upstream?

[rydenfan]

I believe this thread has clearly runs its course. Hopefully Jim will lock it down or move it today.

[BrianM]

I believe this thread has clearly runs its course. Hopefully Jim will lock it down or move it today.

Sorry, I need some confusion cleared up if possible. Is this just your opinion, or are you posting in some official (or semi-official) capacity? I ask because you have 'Volunteer' by your name, yet this is Jim's circle so obviously he can decide whether a thread gets locked or moved. Also because he expressly said he wanted the thread left open back on page 1.

What exactly determines whether a thread has run its course? There are potentially still lots of people who might have things to add, or questions, who haven't piped up yet. Just wondering.

[zybar]

A significant number of audiophiles are running tube amps. Is it unreasonable to suppose that the distortion characteristics associated with vacuum tubes would likely mask whatever subtle improvements had been made in the digital transmission upstream?

Why are you equating tube amps with distortion?   

Well designed tube amps can (and do) have low distortion figures. 

I can assure you that my tube amps aren't masking any details.  In fact, they pass more information than the solid state amps I own or have tried.

George

[BrianM]

I'm not equating them with distortion, I'm associating them with distortion. I'm sure there are some that measure well, but there are also different ways of looking at measurements. Subjectively, most of the tube amps I've heard seem to impart a certain color to the sound, which has little to do with the amount of detail. Which is why I asked.

I don't have an opinion on power supply upgrades affecting an SPDIF line. From what I've read about jitter, it's measurable but occurs well below the noise floor (assuming a competent DAC).

[rajacat]

I'm not equating them with distortion, I'm associating them with distortion. I'm sure there are some that measure well, but there are also different ways of looking at measurements. Subjectively, most of the tube amps I've heard seem to impart a certain color to the sound, which has little to do with the amount of detail. Which is why I asked.

I don't have an opinion on power supply upgrades affecting an SPDIF line. From what I've read about jitter, it's measurable but occurs well below the noise floor (assuming a competent DAC).

Don't SS amps color the sound too? If that's not the case then all SS amps, aside from distortion issues, would all sound the same? In fact you can change the sound of SS gear by simply changing a few caps.

-Roy