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Blumlein 88, do you understand what JA actually measured? I read his review in Stereophile several times, but I must be stupid. I guess that he used a PC or Mac to generate a J-test signal. He connected the V-Link to a USB output of the computer. Then he says that he measured the eye pattern by connecting a 15' plastic cable from the TOSLINK output of the V-Link... to what? I don't see a TOSLINK input on the AP 2722. This eye pattern is so good that it defies belief. The sample rate of the excitation appears to be 96kHz. If TOSLINK works this well at 96kHz, I guess it would work well at 10x this sample rate -- maybe even 100x -- yet conventional wisdom is that optical cables don't support sample rates in excess of 96kHz. I suspect that he connected the optical cable to a TOSLINK-S/PDIF converter and then connected its S/PDIF output to the AP 2722. If so, I wonder whether the converter filtered out the jitter.
I am assuming from his description he connected the Vlink (which is a USB to SPDIF converter) to his Macbook via USB. Then fed via Toslink from the Vlink to the AP to record and measure.
Some Toslink gear does work at 192 khz though most gear stopped at 96 khz. I don't know if early Toslink was limited by cable or the optical circuits. I would think the latter.
ADAT uses the same optical circuits and opti-cable, but is a different format than Toslink. It can carry 8 channels at 48/24 or 2 channels at 192/24. I don't know if that is a physical limit of the medium or just an agreed upon standard from years ago. The type encoding of ADAT uses twice the baud rate of Toslink so it would be similar to 384/24 over Toslink. That is said to be compatible with the earliest Toshiba based transceivers of the optical signal. My guess is the cable is not the bottleneck. Probably the circuits.
Early suggestions were to limit optical cable Toslink to 10 meters. But lots of low cost gear now promises and delivers good performance at lengths of 40-140 meters. So probably for shorter distances modern cable/circuitry could work at much higher rates those simply aren't part of the standard. I know I have a piece of cheap 35 foot cable that works with no glitches or hitches with satellite TV boxes and a 12 year old AVR. At different times I have used it for ADAT transfer with some inexpensive gear.