Cable length usb a to usb b

[JOHN VAN BAVEL]

I am playing back flac files from my computer to dac then to amp . At present I have to have my computer close to the dac because of the length of the usb cable . Would it have any appreciable effect on the sound quality if I used a cable say 6 metres long rather than the 1 metre at present . I know that for analog cables the shorter the better but is it true for usb ?

 

[Mongeddavid]

I believe and stand to be corrected here that 5m was generally regarded as max specified length however if it works over that then all is good

 

[cj66]

I believe you're correct i.e. the max length of a USB cable of correct specification is 5m if you wish data transfer to be guaranteed error free.

 

[JensenHealey]

I ran a very long cable (using a extender) for a while, without any problem. So it is worth a try.

 

[Guest432]

I'm using a 5m USB a>b cable for my Roon PC to DAC with no problems.

Decent well made UGreen cable from Amazon at £12.99

 

[mansr]

I believe and stand to be corrected here that 5m was generally regarded as max specified length however if it works over that then all is good

The USB 2.0 spec limits the signal delay between host and device to 30 ns of which the cable is allocated 26 ns. With a typical propagation delay of 5 ns/m, the maximum cable length is thus 5.2 m. The reason for this limit is to keep the total round-trip response time for a chain of 5 hubs plus a device below about 1.5 μs (including hub delays and device response time). If there are fewer hubs, a longer cable can be used without violating the timing constraints. Long cables are still disallowed in order to ensure that any combination of compliant devices and cables will always work.

In practice, cables longer than a few metres have trouble maintaining signal quality at the far end, leading to increased bit error rate. If there are frequent bit errors during audio playback, this manifests as ticks, glitches, and drop-outs. Still higher error rates turn the sound into a screeching mess before the connection is dropped entirely. Under no circumstances will a marginal cable have effects like loss of treble or bass.

If you need a long run, simply placing a hub halfway will maintain the signal quality. With a self-powered DAC, even a bus-powered hub will do. Of course, if a single long cable works for you, then there's nothing to worry about.

 

[deebster]

Or if your DAC has optical input get a cheapo DAC with USB in and optical out to act as a converter, sit it next to the computer then run a long optical cable.