Are the Toshiba optocoupler the best (quieter and more linear, fast enough) isolation way over the others isolating technic active chips based too ? I know Andrea is using it as you told but also saw most designers seem to prefer the other way ? It is way above my head, I just ask by curiosity.
yup thanks for the feedback, I indeed asked about their isolation bahavior despite it is before the reclocking. Hesitate myself to use it but after a reclocking on a DAC board of mine... . I wanted something to "break" the signal and ground from a big front end, but certainly does arm after a clean reclocking. Btw off topic, sorry for that.
Just a brief note to those folks using sine wave oscillators with their dacs: Found audible problems with some squarers I have. Turns out they are not as perfect as phase noise plots may suggest, assuming phase noise was ever measured. Ferrites appear to be only one of the problems.
An LTC6957-3 based squarer board was found to have audible cross coupling between channels if both 44kHz and 48kHz family oscillators were connected at the same time. Some of the coupling appears to be power rail related but could be other coupling mechanisms are involved too.
Also, some 74AC11004N based squaring circuits were found not be as clean sounding as one using LTC6957-3. Could be the problem in this case is related to layout and or power, rather than being a problem with 74AC11004N itself. Not sure yet.
The above having been said, ultra-low close-in phase noise clocks through very good squaring circuits seem to have clearly audible advantages over simpler and lower cost alternatives (assuming the rest of the dac is ready for better clocking). IOW, IME clocks are not usually among the fist dac problems to go after.
An LTC6957-3 based squarer board was found to have audible cross coupling between channels if both 44kHz and 48kHz family oscillators were connected at the same time. Some of the coupling appears to be power rail related but could be other coupling mechanisms are involved too.
Also, some 74AC11004N based squaring circuits were found not be as clean sounding as one using LTC6957-3. Could be the problem in this case is related to layout and or power, rather than being a problem with 74AC11004N itself. Not sure yet.
The above having been said, ultra-low close-in phase noise clocks through very good squaring circuits seem to have clearly audible advantages over simpler and lower cost alternatives (assuming the rest of the dac is ready for better clocking). IOW, IME clocks are not usually among the fist dac problems to go after.
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