DS DAC questions and concerns

I received my Corning 3.Optical cable yesterday and I’m a bit frustrated. I can’t really get it to work in any fashion but that may not be the cable’s fault. I actually suspect my USB 3.0 ExpressCard adapter since I’ve had some similar problems in the past with it. I’ll update you’all when I have more info.

Ted Smith said I received my Corning 3.Optical cable yesterday and I'm a bit frustrated. I can't really get it to work in any fashion but that may not be the cable's fault. I actually suspect my USB 3.0 ExpressCard adapter since I've had some similar problems in the past with it. I'll update you'all when I have more info.
The active USB I purchased (A to B) should suffice. I hope.

Ted, you previously replied that an active USB cable is a must at the lengths (over 15 feet) we were discussing. Transparent sells a 30-foot USB cable (their middle line at $650) without any active circuitry. Why would the active cable work versus one like that that isn’t? Would the non-active cable make up for it by using higher quality materials, etc., to avoid compromising the data transmission?

Just curious…

George Moneo said
Ted Smith said I received my Corning 3.Optical cable yesterday and I'm a bit frustrated. I can't really get it to work in any fashion but that may not be the cable's fault. I actually suspect my USB 3.0 ExpressCard adapter since I've had some similar problems in the past with it. I'll update you'all when I have more info.
The active USB I purchased (A to B) should suffice. I hope.

Ted, you previously replied that an active USB cable is a must at the lengths (over 15 feet) we were discussing. Transparent sells a 30-foot USB cable (their middle line at $650) without any active circuitry. Why would the active cable work versus one like that that isn’t? Would the non-active cable make up for it by using higher quality materials, etc., to avoid compromising the data transmission?

Just curious…

Howdy

I suspect the active cable you purchased will work well for the DS.

Not to ding Transparent in particular, but many “audiophile” products stretch the standards in an attempt to gain a nonstandard tradeoff that benefits their customers. It’s always possible that an “illegal” USB cable can outperform a cable that meets the USB standards in some areas or features, but it’s also likely that the “illegal” cable will work well in fewer systems or situations.

For longer lengths in any wiring situation you’ll need some sort of repeater, e.g. an active circuit to cleanup and amplify any signals. The better the quality of the cables involved (or the lower the bandwidth of the signal involved) the fewer repeaters are needed for a particular run length.

In the case of USB there is a maximum “legal” cable length set so that anything that passes the USB acceptance tests will very likely work in any USB system. Those quality standards as specifically chosen so that it’s possible to make lower cost cables that perform well.

Longer USB cables have more jitter. Higher bandwidth cables have less jitter. Lower quality cables have more crosstalk between the data wires and the power wires.

In general for DACs, both jitter and crosstalk are important.

For the DS jitter is less important, but cross talk and grounding issues still affect the sound quality (more than I’d like). An active cable can clean up the crosstalk and allow a smaller grounding loop. Most audiophile cables are optimized for general DACs and some of their cost is wasted with the DS.

In a test between Paul’s favorite USB cable an another one, Paul was very surprised that I and another fellow present liked the other cable better. We were sort of surprised that Paul liked his favorite cable better. When we get to this level of performance personal preference is much more important than the technical differences in many cables.

-Ted

I have one of these coming on the next shipment. I plan on putting on top of my HTPC. I think 10 inches for USB cable length. Do you recommend a minimum cable length?

Welcome, drmark!

Michael Ritter, an excellent engineer and Pacific Microsonics and Berkeley Audio Design founder, recommends 1.5 meters for S/PDIF, AES/EBU and USB cables. This avoids signal corruption from bounce-back reflections.

In a nutshell, digital receivers have gated inputs. The gate is opened at intervals to read the incoming signal. The receiver locks onto the signal and ignores signals arriving past the gate time.

When a too short cable is employed, the reflected signal returns quickly enough after the real signal, finds the gate still open, zips through and is mixed with the real signal. This arguable impacts the decoding process.

As i recall, the calculations suggest a minimum of one meter length to avoid this potential issue. The other recommendation is to keep the digital cables away from the components and all other cables, especially power cords.

Can I connect my DS to my mini direct, ie without a router, if so is the cable different ?

What is a mini direct? Is this an Apple IThingy?

Elk said What is a mini direct? Is this an Apple IThingy?
No just my name for going direct from mini to DS, I have the same question for my win laptop.

Sure, makes sense. :)

It depends what type of connection we are talking about. Is this USB, TosLink, S/PDIF, AES/EBU, Ethernet?

Ethernet, trying to eliminate router and switch I normally use to see if bridge will connect,has never yet on DS ( and most of the time on PWD II).

Got it.

I am close to useless as I do not use the Bridge, but it should work directly and I would expect a direct connection to be the best option. A router and/or switch should not make the connection more robust - yet in your circumstance it seems to. Frustrating I am sure.

Hopefully the more useful members will chime in soon.

Thks Elk, yes very frustrating but I’m used to it by now

I haven’t tried it but I think I have read that others have used a direct connection with a crossover cable (or regular ethernet cable with a crossover adaptor) and then gone wireless from the Mini into a router for the internet connection and control point. Don’t know what settings you use on the Mini, unfortunately.

stevem2 said I haven't tried it but I think I have read that others have used a direct connection with a crossover cable (or regular ethernet cable with a crossover adaptor) and then gone wireless from the Mini into a router for the internet connection and control point. Don't know what settings you use on the Mini, unfortunately.
I think I have too, do you know what's different about a crossover cable ?

I think the pins are switched around. If you use a router or a switch that device automatically adjusts. You just need a crossover cable when you’re going direct from one device to another (like two computers). The cables look the same. You can get an adaptor and just use a regular ethernet cable. The adaptor just looks like a plug with a socket on the other end. Here’s one example: http://www.amazon.com/Cables-Unlimited-Cat6-Crossover-Adapter/dp/B00030BYJI/ref=pd_bxgy_e_text_z

rogerdn said
stevem2 said I haven't tried it but I think I have read that others have used a direct connection with a crossover cable (or regular ethernet cable with a crossover adaptor) and then gone wireless from the Mini into a router for the internet connection and control point. Don't know what settings you use on the Mini, unfortunately.

I think I have too, do you know what’s different about a crossover cable ?


If I am not mistaken, the newer Macs are smart enough that you can use either cable. Try it and see.

Not sure what vintage is required.

EDIT

Just found this.

It calls for a crossover cable but worth a try with what you have or pick one up at best buy.

http://www.audiophilia.com/wp/?p=11352

Thks Gordon, I already have both statics so just need the crossover to try it. But then I lose my internet unless I go wireless, not a good trade off probably.

Ted, et al,

I received my Channel Islands Audio VPC3 passive preamp last night and hooked it up to the Bryston, with the Oppo as my first input; the DS DAC will be input number 2. I had zero issues. No power connection makes it deathly quiet. A good purchase, I’d say, and good design by CI. (CI has a 5-input version for $900.)

I connected the Mac Mini to the Oppo’s USB DAC input using the 25-foot active USB cable I purchased as recommended in these pages. I set the Oppo as the output device, set the max upsampling rate to 176.4, and let 'er rip. Everything sounds great. Even old MP3s I hadn’t heard in a while were nominally better. Not that they were good to begin with, of course, but now a tad more tolerable. High-res content – AIFFs, FLACs, Apple Lossless and WAVs sound uniformly excellent.

I can’t wait to get the DS DAC to start comparing the two devices.

-g

gordon said
rogerdn said
stevem2 said I haven't tried it but I think I have read that others have used a direct connection with a crossover cable (or regular ethernet cable with a crossover adaptor) and then gone wireless from the Mini into a router for the internet connection and control point. Don't know what settings you use on the Mini, unfortunately.

I think I have too, do you know what’s different about a crossover cable ?

If I am not mistaken, the newer Macs are smart enough that you can use either cable. Try it and see.

Not sure what vintage is required.

EDIT

Just found this.

It calls for a crossover cable but worth a try with what you have or pick one up at best buy.

http://www.audiophilia.com/wp/?p=11352


Gordon,

Does anyone know if this router-less Ethernet connection would also work on the DS?

Would I have to wait on the Bridge2 for it to work?

Ted Smith said
I received my Corning 3.Optical cable yesterday and I'm a bit frustrated. I can't really get it to work in any fashion but that may not be the cable's fault. I actually suspect my USB 3.0 ExpressCard adapter since I've had some similar problems in the past with it. I'll update you'all when I have more info.
Any news on this one, Ted?

I am on the verge of buying it too.