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Old 14th September 2008, 02:28 PM   #991
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FMAK, you may also need to set switch 4 low. (remember after setting switches you must cycle power).

Your SPDIF signal may need a wider DPLL window.
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Old 14th September 2008, 02:47 PM   #992
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Quote:
Originally posted by Russ White
FMAK, you may also need to set switch 4 low. (remember after setting switches you must cycle power).

Your SPDIF signal may need a wider DPLL window.

Russ

My spdif output locks on any narrow pll (<100 ppm). Supplied by PC to Apogee Big Ben and measuires accurately.

I just did what you suggested. Still won't lock on >48k.

My signak is fine. It locks on a 100 ppm dual pll dejitter box, on a rme dac, on a dCS Purcell, but not on the Buffalo with SW4 set low or high.

Actually regardless of the SW4 setting, the lock light flickers on sometimes and produces a series of pops.

I think either the comparator or the Buffalo is at fault.

Can you ship a tested one and I shall return mine.

Problem not withstanding, the Buffalo sounds v good at 44.1k but better with slow roll off.

Fred
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Old 14th September 2008, 03:04 PM   #993
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FMAK,

Sure, send it in, but I am just surprised it would lock at all if there was a problem with the ESS chip or the comparator.

What level is the SPDIF? Is it .5V?

Someone on the forum needed to reverse the phase (swap input wires) of their transformer coupled SPDIF input.

Cheers!
Russ
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Old 14th September 2008, 03:30 PM   #994
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Originally posted by Russ White
FMAK,

Sure, send it in, but I am just surprised it would lock at all if there was a problem with the ESS chip or the comparator.

What level is the SPDIF? Is it .5V?

Someone on the forum needed to reverse the phase (swap input wires) of their transformer coupled SPDIF input.

Cheers!
Russ
Russ

0.5V and looks good square wave. BNC input sockets. i will double check phase.

Where do I send it to and do you have a tested one on >48k I can have please?

Fred

ps: It just occured to me that it may also be the onboard XO. What freq is it and should I check.
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Old 14th September 2008, 03:39 PM   #995
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Originally posted by Russ White
FMAK,

Someone on the forum needed to reverse the phase (swap input wires) of their transformer coupled SPDIF input.

Cheers!
Russ
Weird, I reversed the spdif socket connection and itlockes at 88.2k but not 96k. Whole thing does not sound good at all!!!

What's happening?

Fred
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Old 14th September 2008, 03:40 PM   #996
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fi Fred,

The XO should be 80mhz.
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Old 14th September 2008, 03:42 PM   #997
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Fred, you might check the output of the comparator with your scope.

You can get the comparator output signal at the SPDIF switch.
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Old 14th September 2008, 03:48 PM   #998
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Fred, you might check the output of the comparator with your scope.

You can get the comparator output signal at the SPDIF switch.

You mean across the switch?

What should it look like?

Re XO; does freq tolerance matter to the Sabre ?

Fred
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Old 14th September 2008, 03:55 PM   #999
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Quote:
Originally posted by fmak



You mean across the switch?

What should it look like?

Re XO; does freq tolerance matter to the Sabre ?

Fred
With the SPDIF switch closed, measure the comparator output from either end of the switch and GND. It should look the same as the SPDIF input but level shifted upward. terminal "D2" would also be the same net, so you can use that as your measurment point too.

XO Freq just needs to be stable and clean. Exact freq is not critical. But in our case it needs to be ~80mhz to do up to 192khz SPDIF input.
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Old 14th September 2008, 04:07 PM   #1000
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Originally posted by Russ White


With the SPDIF switch closed, measure the comparator output from either end of the switch and GND. It should look the same as the SPDIF input but level shifted upward. terminal "D2" would also be the same net, so you can use that as your measurment point too.

XO Freq just needs to be stable and clean. Exact freq is not critical. But in our case it needs to be ~80mhz to do up to 192khz SPDIF input.
Russ

The comparator seems screwed up; I have very nice eye pattern on the spdif connector. At the comparator, I no longer have a crossover intersection mid way between max and min. The two square sections are now separated by a step to the negative side of the wave. Something is wrong.

Please give address to send board back to. Can you send a working one simultaneously; I am anxious to have it working at hirez!.

On limited hearing, the Ivy seems superb - very transparent which is rare.

Fred
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