Sorry, my response was not directed at you specifically 325xi in any way, I wasn't trying to mock or be in any way insulting. Apologies if it came across like that. I was actually amplifying Phil's very correct response and the references from other sources on this topic. I guess I suspect that that trying to answer your question is going to induce a certain reaction and I guess I was getting ready in advance for it.
TOSLINK is just a LED with a piece of plastic. There is NO QUESTION it is inferior to a high end 10 Gb/s OC48 or OC768 (if you can find one) short haul or long haul interface. Those optics are dealing with electro-optic interfaces with clock cycles in the .1ns - 1ns regime. That's fast. Audio is 44.1 KHz. That's slow. At 44.1KHz you are dealing with clock cycles in the 20us regime, 5 orders of magnitude slower. So clocks are slower, equipment can be less "good". A LED is easily "good enough" in this regime for some value of "good enough". But the question is if an TOSLINK is "less good" than the 75ohm variant. Maybe yes, maybe not. Its measurable for sure. But I don't think that is really the issue. The issue is what is the requirement for the transport? What specifications must it support? So I think you question might break down as: a. is there any intrinsic physical reason why an optical connection of LEDs and plastic is less good (for some measures) than coax? b. Is toslink as a syncronous architecture defective to the requirements? c. are there possible manufacturing design reasons one is less than another d. does this in any way matter to the listening experience? Is it audible? (a) I know of no reason, intrinsincally, that a LED and plastic cable should not be able to match coax FOR THE REQUIREMENTS at hand. It might have some slightly better rise & fall propertises depending on the LED selected, (I would need to look into that) but I doubt it - communication LED technology has come a long way and is dirt cheap now. Low end networking gear doesn't use real lasers anymore as this technology has improved so much over the years. b) well, depends on what you want it for. Seems to do ok for consume grade audio motion. Its definately got weak points. But I wouldn't classify it as flawed. Let's look at the requirement. If you accept (and here is the issue) that audibility is +-.5us or so, then you are asking for a LED with switching characteristics in the .5 MHz regime. Thats SLOW. So I would really doubt this is a problem. I stand to be corrected on this by some spec sheets of common gear. c) yes, it is possible some manufacturer fubared their design. If so its not TOSLINKs fault as a design. Bad cables impact networks the world over. But in a .5-1 MHz signal regime the cable has to be pretty appaling. d) This is the kicker. If you think that you need +-100ps jitter control on a TOSLINK connection than there is no way a LED and plastic can achieve that. If you think you need +-.5us I don't see how it couldn't achieve it. Its all in the requirements you believe a TOSLINK has to achieve. I'll do a little research and check some numbers here on this to confirm my intuition on this. Hopefully this is a better answer... -- Eric Carroll Transporter-Bryston 3B SST-Paradigm Reference Studio 60 v.4 SB3-Rotel RB890-B&W Matrix 805 SB3-Pioneer VSX-49TXi-Mirage OM7+C2+R2 ReadyNAS NV+ ------------------------------------------------------------------------ Eric Carroll's Profile: http://forums.slimdevices.com/member.php?userid=9293 View this thread: http://forums.slimdevices.com/showthread.php?t=33146 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
