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Connecting DAC with PC via 30-50ft long USB Cables

vladc77

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I had no choice but to use a 33ft USB to connect DAC - Gustard X26 Pro with a PC to stream music from JRiver Media Center. I use the Monoprice USB cable - https://www.monoprice.com/product?p_id=7531. Previously, I used a decent quality 2m USB cable from Nordost. I expected to hear a noticeable downgrade in sound quality using Monoprice cable. However, I did not hear any changes in sound quality at all. I use Gustard X26 Pro DAC with Yamaha AS3000 and Yamana NS2000 speakers which should be a good setup to identify sound quality issues.

I want to learn how the length of the USB cable negatively affects the quality of the sound. Should I hear that? Did anyone have the same experience as I do?
 
I want to learn how the length of the USB cable negatively affects the quality of the sound.
The only way that any cable transmitting digital data (USB, Ethernet, HDMI, Toslink, Coaxial, AES3) can negatively affect the quality of sound is by introducing stutter, dropouts, etc.

It is physically impossible for one of these cables to give you a stable connection, but subtly degraded sound quality like blunted details, weak bass, narrow soundstage, etc.

If you have a stable connection without any stutter, then you can be sure that you're getting the full audio fidelity.

Once you realize that, fancy Hi-Fi cables like your old Nordost become particularly silly acquisitions.
 
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I found this. (You got lucky.)

Digital doesn't degrade gradually like analog. Usually it's perfect (ones remain ones and zeros remain zeros) or the data gets badly scrambled and you might get no audio at all, or bad interruptions and clicks & pops. This isn't a perfect analogy but one flipped-bit in your bank account is just as likely to make a 1 billion dollar error as a 1-cent error.
 
I expected to hear a noticeable downgrade in sound quality using Monoprice cable. However, I did not hear any changes in sound quality at all.

That's because no analog audio is transmitted over the USB cable. The USB connection only carries digital information. As with any digital data transmission medium, there are only two states that the connection can be in, it works or it doesn't.

I want to learn how the length of the USB cable negatively affects the quality of the sound.

Again, the length of the USB cable has no effect on the analog audio because no analog audio is transmitted over the connection. Any USB repeater/extender cable that you use—as-long-as it regenerates the signal with integrity in regards to the original signal—will work just fine.
 
It doesnt affect the quality of the sound, the DAC is converting the digital.

Plus the cable you bought has a booster to allow max transfer rates so you can listen to your 32 bit wav files :)

It contains active electronics which boost the USB signal for maximum reliability and performance over extended distances. It connects your PC to any USB device with Type B female port up to 10m(33ft),
 
Technically speaking, it's possible for a cable to reduce sound quality and not just cut out. If you have a network stream with a codec like Opus and have packet loss in the cable, Opus can degrade gracefully and still deliver sound but at a lower quality. However, this basically only happens with online meetings over a spotty WiFi connection, so you don't need to worry about it.
 
Technically speaking, it's possible for a cable to reduce sound quality and not just cut out. If you have a network stream with a codec like Opus and have packet loss in the cable, Opus can degrade gracefully and still deliver sound but at a lower quality. However, this basically only happens with online meetings over a spotty WiFi connection, so you don't need to worry about it.
USB is not like a network cable. It’s a totally different topology and should therefore only be used as a comparison in very limited use cases.

Most networking protocols will retransmit data if it doesn’t reach the other side (in case of TCP), and if bandwidth is not wide enough, the application layer can request a lower bitrate version.

Some streaming protocols use UDP because it has less overhead, so is mostly used for realtime video and audio streaming. Here, you’ll just miss data when a packet is dropped and the codec must try to fill in that gap somehow. Eventually that may lead to a selecting a lower bitrate version as well.

USB is more similar to UDP, in that it cannot retransmit missing audio data. The receiver can only check the integrity of the packet, and needs to drop it if it’s constrains errors. It however will not lower the connection speed in case of high BER (bit error rate). So a too long or bad cable may lead to dropouts or no sound at all. Lowering the sample rate manually may yield some improved results in some cases, but since the actual bitrate of the USB doesn’t change, this doesn’t always yield good results (you’ll just have more idle time).

As @Basic Channel mentioned, the cable the OP uses, is an active cable, and this is basically mandatory when using USB lengths of more than 5 meters (~16ft). These devices either boost the signal (or use LVDS), or use an optical link to transmit data over longer distances and are therefor an excellent solution for these use cases.
 
@voodooless I never actually claimed anything about USB cables, just how network packet loss can cause graceful degredation of Opus.
 
@voodooless I never actually claimed anything about USB cables, just how network packet loss can cause graceful degredation of Opus.
Then why bring it up in a discussion about USB cables? If someone sends me mail via pidgin and the pidgin gets eaten by a cat, I also don’t get my letter. That is no reason for me to mention it.
 
Then why bring it up in a discussion about USB cables? If someone sends me mail via pidgin and the pidgin gets eaten by a cat, I also don’t get my letter. That is no reason for me to mention it.
The only reason I brought it up is because it's commonly claimed that cables can't only partially affect sound quality, when in reality it's possible but only in certain circumstances that normal people don't need to worry about.
 
The only reason I brought it up is because it's commonly claimed that cables can't only partially affect sound quality, when in reality it's possible but only in certain circumstances that normal people don't need to worry about.
But it’s not the cable doing it, it’s the application, and as I mentioned, in case of USB, this does not apply.
 
Technically speaking, it's possible for a cable to reduce sound quality and not just cut out. If you have a network stream with a codec like Opus and have packet loss in the cable, Opus can degrade gracefully and still deliver sound but at a lower quality. However, this basically only happens with online meetings over a spotty WiFi connection, so you don't need to worry about it.
I don't use any codec like Opus. I send the pure ASIO signal from the computer. I hope it is the correct way.
 
So, it looks like adding any additional USB card as a Jcat XE card to improve the quality of the sound is just wishful thinking.
 
I don't use any codec like Opus. I send the pure ASIO signal from the computer. I hope it is the correct way.
Yes it is. USB audio always sends raw PCM or DSD data packets to the DAC, except for rare occasions like DOP (just another way to transfer DSD) or curiosities like MQA, that decode additional data from bitperfect transported PCM data.
 
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So, it looks like adding any additional USB card as a Jcat XE card to improve the quality of the sound is just wishful thinking.
Yes it is. In decently designed DACs, the USB clock is totally asynchronous to DACs clock domain, and therefor it’s performance is irrelevant. Noise can be an issue in some cases with USB, but there are far cheaper solutions to these issues. In any case, I doubt that this card will help you with ground loops. If you don’t hear any noise, you don’t have a noise problem.
 
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Yes it is. In decently designed DACs, the USB click is totally asynchronous to DACs clock domain, and therefor it’s performance is irrelevant. Noise can be an issue in some cases with USB, but there are far cheaper solutions to these issues. In any case, I doubt that this card will help you with ground loops.
Great! Thank you all for sharing your wisdom and knowledge!
 
Corning makes an optical USB cable in long lengths. It doesn't transmit power of course, only data. Archimago did a big article and measurements on it.

It's not cheap, but might be better than other options.
 
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