Is there a Michael Fremer of CD transports? If no, DEAR GOD PLEASE SEND US ONE!!!!

[spiritofmusic]

Al, take it from me that my description is wholly a positive
You may have an issue w streaming
I have an issue w streaming AND most digital until my easing into it w the Eera
So for me to praise streaming in analog terms is a massive positive in my book

 

[asiufy]

Well, we have a happy new Innuos Zenith owner among us! When he eventually surfaces from all the fun he's likely having, I'm sure he'll be happy to report on it...

I agree with LL21's post in response to astrostar. It really comes down to implementation.

If you look at that open case CD transport, it's a fairly simple device. Now a server, any server, is likely a much more complex device, and thus, much harder to implement right, with a lot more pitfalls on the way. Once more of those pitfalls are known and avoided, the overall performance levels on streamers/servers will match the theoretical expectations.


cheers,
alex

 

[microstrip]

(...) Interestingly, I have now heard two or three times that a certain server that is highly regarded in the audiophile community sounds lifeless. If I hear that from one source, that's interesting, but when I hear that independently from different people having heard it in different systems, a pattern seems to emerge. (...)

Al M.

Independently, specially about computer audio, in the age of internet? Sorry in this matter I only believe in what my ears listen in my listening room - and I find I need a very long listening time before having an opinion.

Can you tell us about the "pattern" that seems to emerge? I find opinions on this subject almost chaotic!

 

[spiritofmusic]

Alex, I’m a partial convert.
Remember, I’ve had a couple of dozen visits to Barry’s system sporting a fantastically impressive SGM install.
I’ll come clean, I just can’t warm to a computer interface for my leisure, I find the constant hum of issues re computer audio a real drag (nearly every review of a streamer has a middle part concerning streamers not talking to dacs or The Cloud etc), the need to combat noise in streaming solutions requires more superhuman effort than even analog.
And also, having spent 15 years finding the cdp that talks to me, I’m pissed off that in effect streaming obliges one to start over again.
But I really like the SGM .
Rant over (until next time).

 

[Al M.]

Al M.

Independently, specially about computer audio, in the age of internet?

One opinion did not come over the internet, but was a personal communication. So yes, I do think those were independent opinions.

Sorry in this matter I only believe in what my ears listen in my listening room - and I find I need a very long listening time before having an opinion.

Sure, ultimately our ears are the final arbiter, you're right, and a final judgment should wait for an opportunity to hear for ourselves. However, I find the convergence of such opinions striking. To me personally, it cannot be as readily dismissed as common negative views about certain speakers for example that can easily be due to amp/speaker mismatches, or auditioning under suboptimal show conditions. Of course, you will say everything is a synergy, even servers, and perhaps you even have a point with that.

 

[microstrip]

One opinion did not come over the internet, but was a personal communication. So yes, I do think those were independent opinions.

Thanks, I see now you are referring to a very limited number of opinions - I fail to see how we can speak of patterns with such numbers.

Sure, ultimately our ears are the final arbiter, you're right, and a final judgment should wait for an opportunity to hear for ourselves. However, I find the convergence of such opinions striking. To me personally, it cannot be as readily dismissed as common negative views about certain speakers for example that can easily be due to amp/speaker mismatches, or auditioning under suboptimal show conditions. Of course, you will say everything is a synergy, even servers, and perhaps you even have a point with that.

Just to be sure, what opinions are you exactly addressing? BTW, I say that most, not everything, is preference and synergy. But I do not have experience enough to have opinions on servers, although I have listened to CD transports adequately matched sounding excellent. But my absence of experience with good servers perhaps only tells that I am not yet prepared to spend a large sum in a server!

 

[Empirical Audio]

Interesting. I gave up on transports many years ago. It doesn't take much to understand that physical spinning a disc live, then sending that data to a DAC has to have correction circuits and timing error issues, not to mention data read issues as well. If we send data from a file sat on an SSD there is no moving parts, so that in theory gets that problem out of the way.

As I see it, the sending of the data from a music server or PC / Mac is the next problem, how to get it with zero latency, and give the DAC the best chance of reading it.
And avoiding sending noise from the server to the DAC.

This is another ideal place to insert a Synchro-Mesh. Low jitter and galvanic ground isolation.

Then the DAC uses it's on board re-clocking / buffer to correct any additional jitter incurred in the sending process.

That would be nice in a perfect world, but that's not the world we live in. Input jitter still matters and the master clock inside the DAC doing the re-clocking is likely inferior to the one in the Synchro-mesh, so you are better off with a DAC that has no resampler on the input.

So far, I find sending via Ethernet sounds the best in my system, and my end point is SPDIF.

Likewise. That is why I stopped USB designs and designed an Ethernet interface. This is the best sounding interface I have offered yet.

Steve, what is your preferred entry protocol to the DAC? Is it SPDIf, AES, I2S? I am talking Redbook or 96K~ data rates, I don't use higher and don't upsample in my server, plus my DACs are NOS.

Thoughts?

Each type of input has its advantages and limitations:

S/PDIF - This can have very low jitter and galvanic isolation can be added at the driving or receiving end (it does take a small hit on jitter though). The downside is that some DACs don't use high-performance S/PDIF receivers, so the PLL in these can add audible jitter. I use the EK4114 because it adds insignificant levels of jitter. The 75 ohm cable and connectors can have a very good impedance match, particularly if it is a BNC terminated cable with 75 ohm RCA adapters.

AES/EBU - This is a higher voltage interface, so it must have an additional stage to get that higher voltage. This adds jitter. Minimizing stages is a key element in minimizing jitter. There is also the issue of the XLR connector not be matched impedance of 110 ohms. Because it is differential, it has the advantage of some common-mode noise rejection, but can also be galvanically isolated with a pulse transformer (adds jitter). It is my least preferred interface for these reasons.

I2S - This is a direct connection to the D/A logic, so it has the potential for lowest added jitter. The problems are that it can not be galvanically isolated without adding significant jitter and the cable in order to match the performance of S/PDIF must be quite expensive. If you are talking HDMI I2S like PSAudio, this is more strictly defined and terminated. If you are talking single-ended I2S on RJ-45 or the like, this can vary a lot as to termination technique, cabling and pinouts. I use both HDMI I2S and RJ-45 SE I2S. They sound great, but only marginally better than my S/PDIF, so I usually use S/PDIF myself. I think my S/PDIF cable is better than my silver I2S cable anyway.

Steve N.
Empirical Audio

 

[analogsa]

If i may offer another reason as of why optical transports sound different to computer-based. Consider a basic optical transport: there is generally a single clock at a limited frequency, usually between 12-16MHz. There are other sources of electrical noise as well, but current consumption is low and the noisy bits draw at worse hundreds of milliamps.

Compare this to a computer transport with a full orchestra of clock sources reaching many gigahertz and a current hungry processor drawing tens of amps. As far as radiated noise goes, the two are hardly comparable.

 

[Empirical Audio]

If i may offer another reason as of why optical transports sound different to computer-based. Consider a basic optical transport: there is generally a single clock at a limited frequency, usually between 12-16MHz. There are other sources of electrical noise as well, but current consumption is low and the noisy bits draw at worse hundreds of milliamps.

Compare this to a computer transport with a full orchestra of clock sources reaching many gigahertz and a current hungry processor drawing tens of amps. As far as radiated noise goes, the two are hardly comparable.

All of this depends on implementation. It is actually not that hard to make either a low-noise environment that delivers low-jitter.

The reality is that most computer-based or server-based sources are easier to get low jitter from than a typical optical CD transport. It turns out that the reading of the bits from the optical disk and the two or three motor servos involved generate a lot of noise, maybe more noise than a well designed computer like a Mac Mini. Most of those GHz frequencies are on-die only and the switching power supplies handle it just fine. It's not intuitive at all. One must be a EE and a designer to understand all of the details.

If you study some of the best CD transports on the market, you will find that many of them are simply special purpose computers with CDROM drives that read the data at high speed and spool the output from a buffer memory at low-speed.

If it were so easy to make a CD transport deliver low-jitter, then why would any company design one that is basically a computer?

Steve N.
Empirical Audio

 

[analogsa]

This is the reason i mentioned nothing related to jitter: it is trivial to design a file player in which the jitter is reduced to that of the clocks plus a pico gate. As for the transports that are simply disguised computers...they also sound like computers.

 

[Al M.]

But my absence of experience with good servers perhaps only tells that I am not yet prepared to spend a large sum in a server!

To me it's the opposite. From what I have heard so far, and with all the hassle that is often involved, the one route that would interest me to potentially short-cut all the problems (except the external storage that is still needed) is an expensive dedicated server, like a Baetis that features an AES/EBU output, which I prefer.

Fortunately, if I ever want to venture into computer audio (no appetite whatsoever currently) I can audition a Baetis server from my local dealer (Goodwin's High End) to see if I even like computer audio and the sound quality that such a device can offer.

 

[Empirical Audio]

To me it's the opposite. From what I have heard so far, and with all the hassle that is often involved, the one route that would interest me to potentially short-cut all the problems (except the external storage that is still needed) is an expensive dedicated server, like a Baetis that features an AES/EBU output, which I prefer.

Fortunately, if I ever want to venture into computer audio (no appetite whatsoever currently) I can audition a Baetis server from my local dealer (Goodwin's High End) to see if I even like computer audio and the sound quality that such a device can offer.

A good start, but this will only show what a Baetis can offer, not what all servers can offer. You would need to try an Aurender N10 with a DAC with a quality USB interface and a quality USB cable to hear what is possible.

Steve N.
Empirical Audio

 

[microstrip]

To me it's the opposite. From what I have heard so far, and with all the hassle that is often involved, the one route that would interest me to potentially short-cut all the problems (except the external storage that is still needed) is an expensive dedicated server, like a Baetis that features an AES/EBU output, which I prefer.

Fortunately, if I ever want to venture into computer audio (no appetite whatsoever currently) I can audition a Baetis server from my local dealer (Goodwin's High End) to see if I even like computer audio and the sound quality that such a device can offer.

When going in servers we must forget what we preferred with CD transports. IMHO CD transports have a strong sound signature, that we like, and does not seem reproducible in servers.

 

[Pb Blimp]

I just got off the horn with Vince Galbo regarding my new MSB Reference DAC which is in transit. We talked because I was curious about whether the new Roon/MQA Renderer (which has been in the works for some time) was finished in time to make the shipment. Unfortunately it is still a couple weeks out so MSB is sending their fourth generation Quad Rate DSD and MQA USB input module.

The point of all this is that I asked Vince if I should consider just keeping their SOTA USB module and buying a SOTA USB source since I have not yet bought my ethernet server. I honestly expected him to say "sure they are essentially the same." His response was emphatically NO! In his opinion the the absolute best source for the Reference DAC is direct to IS2 be it ethernet or their proprietary connection. FWIW.

 

[Al M.]

A good start, but this will only show what a Baetis can offer, not what all servers can offer. You would need to try an Aurender N10 with a DAC with a quality USB interface and a quality USB cable to hear what is possible.

Steve N.
Empirical Audio

Steve, I thought you had given up on USB.

 

[Al M.]

When going in servers we must forget what we preferred with CD transports. IMHO CD transports have a strong sound signature, that we like, and does not seem reproducible in servers.

That is not my experience. My CD transport didn't have a much different sound character vs. server in a comparison.

 

[Al M.]

The point of all this is that I asked Vince if I should consider just keeping their SOTA USB module and buying a SOTA USB source since I have not yet bought my ethernet server. I honestly expected him to say "sure they are essentially the same." His response was emphatically NO! In his opinion the the absolute best source for the Reference DAC is direct to IS2 be it ethernet or their proprietary connection. FWIW.

Interesting, and doesn't surprise me.

 

[Empirical Audio]

Steve, I thought you had given up on USB.

I have changed from a focus on USB to a focus on Ethernet because it performs better and is simpler.

If you want to use a server then USB makes sense. If you want to use Ethernet, then any computer will do.

Steve N.
Empirical Audio

 

[Empirical Audio]

This is the reason i mentioned nothing related to jitter: it is trivial to design a file player in which the jitter is reduced to that of the clocks plus a pico gate. As for the transports that are simply disguised computers...they also sound like computers.

I don't believe this is trivial. I have been designing audio interfaces for 17 years and it has never been trivial. Between the master clock and the S/PDIF output, there is a lot of logic. It also not that easy to get the specified jitter from an oscillator. Requires good power delivery, decoupling and much layout care. It's relatively easy to use an oscillator specified at 10psec and add 500psec to it before the signal reaches the S/PDIF output, much less the end of the cable across the termination. Most designs add this much jitter.

If you believe all computer interfaces sound electronic, you have not listened to the best interfaces.

Steve N.
Empirical Audio

 

[Al M.]

I have changed from a focus on USB to a focus on Ethernet because it performs better and is simpler.

If you want to use a server then USB makes sense. If you want to use Ethernet, then any computer will do.

Steve N.
Empirical Audio

Since USB seems to perform less well I don't see why you think it would make sense in a server. I am interested in the Baetis precisely because its preferred output is AES/EBU.

An added bonus is that I could use my current AES/EBU cable that is feeding the DAC from my transport.