Transporter as server (digital outs)- a few basic questions

[jh901]

Hi- I've recently upgraded to the Cary 306 (see sig) for both SACD and as a DAC for redbook PCM from the Transporter digital outs.

1) Networked by wi-fi, but I was considering a switch to Ethernet. Any length related concerns for ethernet cable?

2) I'm using the coax output of the Transporter for now, but I'm switching to AES since the rest of my system is balanced. Are any of the Transporter outs considered superior (for sound quality)? Most importantly, is the digital output from the Transporter being clocked by the Cary? (I get confused about "Master/Slave")

I have a few more concerns that I'll follow up with as I get my arms around the first two. I appreciate any help and I understand that this stuff will have been covered before, but I'm not real clever with "search" and I want to capture a discussion applicable to my situation all in one thread. Do feel free to post links.

Thank you!

Josh

[garym]

Hi- I've recently upgraded to the Cary 306 (see sig) for both SACD and as a DAC for redbook PCM from the Transporter digital outs.

1) Networked by wi-fi, but I was considering a switch to Ethernet. Any length related concerns for ethernet cable?

2) I'm using the coax output of the Transporter for now, but I'm switching to AES since the rest of my system is balanced. Are any of the Transporter outs considered superior (for sound quality)? Most importantly, is the digital output from the Transporter being clocked by the Cary? (I get confused about "Master/Slave")

I have a few more concerns that I'll follow up with as I get my arms around the first two. I appreciate any help and I understand that this stuff will have been covered before, but I'm not real clever with "search" and I want to capture a discussion applicable to my situation all in one thread. Do feel free to post links.

Thank you!

Josh

maximum ethernet cable length (cat5e) is 100 meters, or a bit over 300 feet. But if you need a longer run than that, just connect to a switch box, then connect new ethernet cable to the switch. So ethernet cable length is rarely a practical limitation....

I can't find the thread, but a couple of years ago there was a good discussion by either John Swenson or Phil Leigh rleated to AES. My recollection was that AES was not considered as good as S/PDIF or TOSLINK. The notion was that AES was created simply because it allowed studios to use the cables and XLR connectors that they already had laying around the studio.

p.s. I may misunderstand what you are doing, but the Transporter BALANCED outs are analog (in fact, this is what I use, Transporter balanced out via XLR into the balanced input of my preamp). If you are going from Transporter to DAC, it seems you'd want to use transporter DIGITAL out into your DAC. The "balanced" part is once you reach the analog stage. That is, you'd want balanced out analog from the DAC into the balanced input of your preamp/amp. The input into your DAC from the transporter just needs to be digital (S/PDIF coax, toslink, or AES are all possibilities here).

[jh901]

Ok. I'm not using the analog outs of the Transporter, but I referred to the AES digital out as "balanced" since it is XLR terminated. Of course, then we have the question of the interconnect quality itself, but that's another topic.

Thanks for the advice on the ethernet. I'll need about 50 feet (less than 20 meters), so I suppose I'll be just fine. Should I expect a slight sound quality improvement using ethernet (vs wifi)?

[garym]

Should I expect a slight sound quality improvement using ethernet (vs wifi)?

you shouldn't expect *any* difference if your WIFI connection is good. Either wifi or ethernet will deliver perfect bits to the transporter. This said, WIFI can suffer interference, etc. that can make it worse. I personally prefer the ethernet connection because I don't have to deal with any potential interference from other wifi networks near me, interference from microwave ovens, etc.

[jh901]

Hm. So how would this interference manifest itself? I haven't had a buffering problem since upgrading my router, so I don't have a concern in that area. I'm trying to work through each part of the data path in order to determine why CDs played in the transport sound better than from the media server (S/PDIF digital out to the same exact DAC). My system resolves at quite a high level, so it's easy to hear intimate musical detail.

Maybe it's a "master-slave" thing with the master clock? I want the Cary to handle everything. It could be that my coax interconnect isn't good enough. Or that the AES digital input on the Cary is better than it's coax. Etc. Just trying to work my way through.

Hoping I can get a few audiophile expert views. Appreciated!!

[garym]

Hm. So how would this interference manifest itself? I haven't had a buffering problem since upgrading my router, so I don't have a concern in that area. I'm trying to work through each part of the data path in order to determine why CDs played in the transport sound better than from the media server (S/PDIF digital out to the same exact DAC). My system resolves at quite a high level, so it's easy to hear intimate musical detail.

Maybe it's a "master-slave" thing with the master clock? I want the Cary to handle everything.

buffering, etc. Sounds like not an issue for you. Regarding sounding better, are you sure you're not comparing while using replaygain values on your digital files (FLAC or WAV I assume). If replaygain values are being used (check LMS > SETTINGS > Players > audio) this could account for what you are hearing. With replaygain being used, most tracks will have volume reduced (not increased). And in blind studies, even an almost imperceptible reduction in volume can lead listeners to prefer the "louder" track.

[garym]

you might also try toslink optical out from transporter as well. Some see EMI noise transmitted via S/PDIF coax connections. And in many cases the S/PDIF coax connectors are not the correct ohm. These are typically such small effects that they are not audible under normal conditions, but perhaps in your system they matter....

[JohnSwenson]

2) I'm using the coax output of the Transporter for now, but I'm switching to AES since the rest of my system is balanced. Are any of the Transporter outs considered superior (for sound quality)? Most importantly, is the digital output from the Transporter being clocked by the Cary? (I get confused about "Master/Slave")

Josh

There is no way to tell which connection method is going to be the best before hand, you just have to try them. There are far to many variables in implementation and cables to make generic judgements.

No, the transporter is not being clocked by the Cary, it's a one way connection between the Transporter and the Cary. IF the Cary had a word clock output the Transporter could be slaved to it, but from reading the website I see no mention made of a wordclock output. So most likely there is a traditional receiver in the Cary which uses a PLL to extract the clock from the digital signal coming from the Transporter. This is almost guaranteed to be significantly higher jiter than the internal clock in the Cary. The sales literature spends time talking about how low jitter the internal clock is, but nothing about how good the input receiver is, so it's probably fairly generic. (If a company has spent effort making a very low jitter receiver they usually make a big deal about it, the Cary does not)

The upshot is that there is not a lot you can do about it, try the three different connection methods and see what you like the best, stick with that.

I am the one who is not particularly fond of AES/EBU, sometimes it can sound the best, but my experience has been that in a lot of cases it is NOT the best sounding interface.

John S.

[jh901]

John S.

Appreciated. Not the answer I wanted, but lesson learned. I'll hope that AES is closer than S/PDIF to CD. The Cary has been an enormous upgrade even with the clock situation. Worst case is that I'll play CDs for any serious listening. Of course, as good as the system sounds now I'll be doing much of that!

Thanks again.

[Phil Leigh]

There is no way to tell which connection method is going to be the best before hand, you just have to try them. There are far to many variables in implementation and cables to make generic judgements.

No, the transporter is not being clocked by the Cary, it's a one way connection between the Transporter and the Cary. IF the Cary had a word clock output the Transporter could be slaved to it, but from reading the website I see no mention made of a wordclock output. So most likely there is a traditional receiver in the Cary which uses a PLL to extract the clock from the digital signal coming from the Transporter. This is almost guaranteed to be significantly higher jiter than the internal clock in the Cary. The sales literature spends time talking about how low jitter the internal clock is, but nothing about how good the input receiver is, so it's probably fairly generic. (If a company has spent effort making a very low jitter receiver they usually make a big deal about it, the Cary does not)

The upshot is that there is not a lot you can do about it, try the three different connection methods and see what you like the best, stick with that.

I am the one who is not particularly fond of AES/EBU, sometimes it can sound the best, but my experience has been that in a lot of cases it is NOT the best sounding interface.

John S.

for what it's worth, I'm not fond of AES/EBU either. It is often poorly implemented at incorrect or incompatible voltage levels. THere can also be grounding issues and there is no galvanic isolation.

Where it works well is in professional location recording setups with runs of hundreds of feet of cable and/or harsh physical environments with rampant RFI/EMI from generators etc. It is worth noting thAt in such situations, reliability is more important than ultimate sound quality.
As garym mentioned it was after all designed purely to reuse those very expensive 300ft drums of xlr-xlr cable snakes that pros have...