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barrygordon
2009-04-25, 09:13
My assumption is that if I play my music out of the optical connection on any Slim Devices player there should be no difference in sound as DAC quality of the player does not come into it. Am I correct in that assumption? That is, a $2000 Transporter and a $120 Receiver should sound exactly the same as far as their optical outputs are concerned.

Phil Leigh
2009-04-25, 09:28
My assumption is that if I play my music out of the optical connection on any Slim Devices player there should be no difference in sound as DAC quality of the player does not come into it. Am I correct in that assumption? That is, a $2000 Transporter and a $120 Receiver should sound exactly the same as far as their optical outputs are concerned.

Maybe.... and then again maybe not. There certainly won't be much in it.
The end result you achieve will depend greatly on the DAC. Also, optical toslink MAY or may not be as good as spdif with some DAC's...

Labarum
2009-04-25, 09:34
Exactly the same? It may depend on the DAC and replay chain you are feeding. S/PDIF optical and through the RCA socket is compromised to some degree. An RCA phono socket is the silliest connector to use, but . . . boxes built to consumer standards seem to love them.

The Transporter, of course, supports up to 24/96. The lesser boxes only up to 16/48.

How much difference this will make in practice, I cannot say.

barrygordon
2009-04-25, 09:48
Perhaps I wasn't being clear. Lets forget about the Audio chain after the player for the moment. Will the exact same digital stream be put out by all of the players to their digital outputs i.e. optical or coxial. I guess that is my question.

I own every type of player that Slim Devices sells, but I have very old ears. In theory however, in the configuration I am discussing, the DAC's in the player should not be used. There should just be a digital format conversion from FLAC to LPCM out of the digital output, or am I missing something? If it is just a format conversion then all digital outoputs should be the same.

barrygordon
2009-04-25, 09:53
Okay guestions bring answers and ansers bring more questions. I understand about the 24/96 vs 16/48, but other than that...

Addressing the connector - so what. It is a digital stream. If all the bits get transmitted with negligible jitter ( a whole other discussion, as I do not believe in it at the rates we are talking about) who cares what the connector or medium of transfer (photons vs electrons) is. Why/how can it make a difference.

I am a digital (hardware and software) engineer with 47 years in the field before I retired, So I know that subject fairly well.

dsdreamer
2009-04-25, 09:55
My assumption is that if I play my music out of the optical connection on any Slim Devices player there should be no difference in sound as DAC quality of the player does not come into it. Am I correct in that assumption? That is, a $2000 Transporter and a $120 Receiver should sound exactly the same as far as their optical outputs are concerned.

Let's assume CD-quality (16 bits per channel x 44.1kHz) is good enough and you aren't going to be buying high-rez FLAC downloads from audiophile music labels.

Then, the only difference could be the clock stability of the source and jitter on edge transitions. The external DAC has to lock onto and recover the clock from a single stream containing both the data and an implied clock. The quality of that waveform, in particular the slope of the transitions between ones and zeros can make a difference to how jittery the recovered clock winds up. True, this is more a function of the counter measures taken inside the DAC, but to a degree it depends on the transmitted waveform quality as well. In fact, that is a reason that an electrical coax connection has the potential to be better, as it can be made very wide band. If the bandwidth is constrained, then you have a low pass filter which causes previous bits to influence the present bit, also known as ISI. This again causes edge-jitter which can impact the quality of the recovered clock.

All this can sound like audiophilia nervosa, but it is scientifically quantifiable and mathematically correct. The only question is how important is it? Most good, modern DACs are designed to mitigate such effects to a large degree. So, depending on the level of ambition you have for your sound quality and the quality of your down-stream audio equipment you may not be able to hear the difference. In fact, the balance of probability is that you won't hear a difference.

My summary: Using a Transporter purely for digital-out makes *most* sense if you think you are going to collect music in higher-than-CD resolution, but also has some theoretical justification if you are going all-out for a no-compromise system and really want to avoid all possible sources of jitter, real or imagined. (But in that case, use the coax output.)

Labarum
2009-04-25, 10:01
You were very clear, but the matter is not as clear as you would like it to be.

The Transporter and the lesser boxes all claim to be "bitperfect", but data can be lost or corrupted in the transfer to you DAC. Whether you can hear this will depend to some degree on the resolution of the DAC and the following analogue replay chain.

In my opinion, you would need to have an extremely high quality replay chain to here the engineering imperfections of the Slimdevices/DAC interface.

The problem playing of 24/96 files is resolved in the latest versions of Slimserver - it will downsample on the fly. Again, whether you can hear the difference between 24/96 and 16/48 will depend on the resolution of your replay chain - and that of your own ears!

peter
2009-04-25, 10:06
barrygordon wrote:
> Okay guestions bring answers and ansers bring more questions. I
> understand about the 24/96 vs 16/48, but other than that...
>
> Addressing the connector - so what. It is a digital stream. If all
> the bits get transmitted with negligible jitter ( a whole other
> discussion, as I do not believe in it at the rates we are talking
> about) who cares what the connector or medium of transfer (photons vs
> electrons) is. Why/how can it make a difference.
>
> I am a digital (hardware and software) engineer with 47 years in the
> field before I retired, So I know that subject fairly well.
>

I tend to agree with you. Ones and zeros are ones and zeros unless they
aren't...

Regards,
Peter

barrygordon
2009-04-25, 10:09
dsdreamer, thank you for the very well constructed and intelligent reply (no denigration to other replies intended). Yes with clock reconstruction as you indicated, there is the case for some waveform edge jitter, but as I said I have old ears so maybe I just waste money on my toys.

The downstream audio is handled by the new Cary Cinema11A which IMHO has a superb sound and is fed into an outlaw 7 channel amp into 7 acoustically matched B&W speakers. Bass is done by a Velodyne servo sub.

I do have a large collection of ripped DTS tracks and some very high end multichannel audio from some of the smaller labels. I buy DTS multichannel CD's whenever I can.

I do use the Transporter in the Music room/theater, Squeezeboxes in the master bedroom and for whole house audio, a receiver for the guest bedroom and a squeezeBoom for the pool deck.

All music is controlled by a set of Pronto PRO remotes running an application that provides full control and full visual feedback from the Squeezecenter of all players.

Once again, thanks to all who replied.

Mnyb
2009-04-25, 10:32
Eh the "lesser" boxes are actually doing 24/48 not only 16/48 .
SC is transcoding 24/96 to 24/48 for the "lesser" players.

Imho a SB3 or SBR will do just fine as a "transport"

The edge the TP has is 96kHz . I have a whooping 20-30 albums of these among my >1440 albums.

And a clock input which can be used if your dac has clock output.

In practice, with my old ears and declining hearing, i find my SB3 identical to my Meridian G98DH dvd player as a source into my my Meridian G68J HT processor/preamp on CD material (16/44) on hi-rez the meridian wins.

pfarrell
2009-04-25, 10:38
Mnyb wrote:
> Eh the "lesser" boxes are actually doing 24/48 not only 16/48 .

Do you really mean 48? or 44.1?

--
Pat Farrell
http://www.pfarrell.com/

funkstar
2009-04-25, 11:38
Do you really mean 48? or 44.1?
48khz is the maximum output frequency of the normal players.

http://wiki.slimdevices.com/index.php/HardwareComparison

pfarrell
2009-04-25, 11:42
funkstar wrote:
> 48khz is the maximum output frequency of the normal players.

Yes, but there is not a lot of material using that maximum. All RedBook
is 44.1


--
Pat Farrell
http://www.pfarrell.com/

Mnyb
2009-04-25, 12:02
funkstar wrote:
> 48khz is the maximum output frequency of the normal players.

Yes, but there is not a lot of material using that maximum. All RedBook
is 44.1


--
Pat Farrell
http://www.pfarrell.com/

Yes quite so, I've seen 48k with 96k transcoding 96/2 I assume that 88.2 material will be downsampled to 44.1
and also some of downloaded stuff i bought has been 24/48 but it is rare.

chenrikson
2009-04-26, 09:26
dsdreamer, thank you for the very well constructed and intelligent reply (no denigration to other replies intended). Yes with clock reconstruction as you indicated, there is the case for some waveform edge jitter, but as I said I have old ears so maybe I just waste money on my toys.

The downstream audio is handled by the new Cary Cinema11A which IMHO has a superb sound and is fed into an outlaw 7 channel amp into 7 acoustically matched B&W speakers. Bass is done by a Velodyne servo sub.

I do have a large collection of ripped DTS tracks and some very high end multichannel audio from some of the smaller labels. I buy DTS multichannel CD's whenever I can.

I do use the Transporter in the Music room/theater, Squeezeboxes in the master bedroom and for whole house audio, a receiver for the guest bedroom and a squeezebox for the pool deck.

All music is controlled by a set of Pronto PRO remotes running an application that provides full control and full visual feedback from the Squeezecenter of all players.

Once again, thanks to all who replied.

We might add that Barry is the author of specialized software that allows using high-end Philips Pronto remotes (TSU9400, TSU9600) with SB applications including the Duet/Receiver! For more info check out Remote Central.

barrygordon
2009-04-26, 09:36
Chenrikson, Thanks for the plug. I have sold over 200 of the Pronto control system (very low price). Many, especially in Europe, have bought into the Slim Solution because of that application for the Pronto.

Nonreality
2009-04-26, 18:26
Chenrikson, Thanks for the plug. I have sold over 200 of the Pronto control system (very low price). Many, especially in Europe, have bought into the Slim Solution because of that application for the Pronto.

Sounds very cool, is there a web page that shows how it all works for us home audio challenged. :)

barrygordon
2009-04-26, 19:40
If you email me or send me a pm with your email address I will send you what I call the purchase kit. It contains the complete manual with many screen snaps, the license agreement and how to buy it. The price is $29.95 via paypal. That does not include the Pronto, just the software for a Pronto. If you already have a Pronto PRO then tell me the model so I can send you the correct package