Computer Audio Asylum Music servers and other computer based digital audio technologies.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Computer Audio Asylum ]

---

[ Alert Moderator ]

---

RE: USB vs S/PDIF

Posted by Charles Peterson (A) on October 6, 2016 at 16:32:03

In Reply to: USB vs S/PDIF posted by Kody on October 4, 2016 at 19:49:11:

Optical SPDIF is usually called Toslink. Toslink is inferior to coaxial SPDIF because it is the same signal run through optical converters which reduce the bandwidth slightly. This reduction in bandwidth means that the downstream converter doesn't catch the transitions as exactly, meaning it can't recover the clock exactly. This is one kind of jitter. Many high end gurus will tell you never to use Toslink for this reason. However, the effect of this transmission-induced jitter is quite likely moot. The DAC will average the timing signal over enough cycles so there is little or no detectable jitter-caused distortion in the analog output. Any device accepting Toslink input knows what it has to deal with, so probably takes sufficient measures to deal with the apparent jitter in the transitions.

I myself have been using Toslink connection from my computer for high rez audio now for about 5 years and I have always thought it sounded fine. However I have recently decided to eliminate all Toslink connections just because they are technically inferior.

Meanwhile I had also decided long ago NEVER to use USB. USB comes from electrically noisy computers and there are no end to the technical problems it causes. I ban computers-as-such (with their constant updates and spying on me) from my listening area. So instead I've used ethernet based devices to bring music to my listening room, first Sonos, now Transporter. Unfortunately IMV these are still available but new ethernet-based high rez players are very expensive. USB has become the mainstream for more audiophiles.

USB is an extremely jittery data delivery system designed for computer peripherals. However, the special Isochronous mode makes it work as if it were a clean synchronous system. Just as with ethernet, there is a buffer on the receiving side which fills up with data and then clocks it out. In theory, neither ethernet nor properly-used USB will actually induce jitter, though they are made of jitter. I'm not sure if this is so iron clad however, I still wonder if jitter leaks through in various small ways. FWIW the lowest jitter device I have right now seems to be a 25 year old CD player outputting SPDIF.

I prefer the simplicity of SPDIF in coax or AES/EBU which is almost the same thing in higher voltage balanced to the packet based system. With SPDIF you just plug it in and you get lock. It hasn't changed in 30 years. No software updates to worry about.

This post is made possible by the generous support of people like you and our sponsors:

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---