That strange. Try opt input to see what's happen. lock led lighting on the spdif board means the spdif signal received without problem.
Did you make sure the digital transformer works well with the socket well?
Or connect your spdif source with coaxial cable to other dac just confirm there is music.
Ian
Update
Some time ago i shared my impressions of the FIFO between an EXA board and a Buf 3.
The sound, in short, wasn't very nice.
Today i finally upgraded the freebie clocks to Crysteks. What a transformation! It certainly now sounds better than without the FIFO.
Of course, a nagging thought: what if the EXA's clocks were replaced instead??
Some time ago i shared my impressions of the FIFO between an EXA board and a Buf 3.
The sound, in short, wasn't very nice.
Today i finally upgraded the freebie clocks to Crysteks. What a transformation! It certainly now sounds better than without the FIFO.
Of course, a nagging thought: what if the EXA's clocks were replaced instead??
Inspired by analog_sa reporting I can have the following experience:
I, for some reason, bid on a 11,2896 "Low Jitter - D/A Mental" osc on ebay. It thad reference to trentlab... don't know why really. Promised -135 at 1k but no other specs really. This was bad due diligence of course but spirited by my new fifo toy. With this XO sound is clinical, maybe "clear" but it's not music. Avoid is my verdict. Maybe I'm lucky with my generic XO that came in the package but it sound really good. I run via Ians s/pdif (in and out) so that could be a reason... but I cant se why...
/
I, for some reason, bid on a 11,2896 "Low Jitter - D/A Mental" osc on ebay. It thad reference to trentlab... don't know why really. Promised -135 at 1k but no other specs really. This was bad due diligence of course but spirited by my new fifo toy. With this XO sound is clinical, maybe "clear" but it's not music. Avoid is my verdict. Maybe I'm lucky with my generic XO that came in the package but it sound really good. I run via Ians s/pdif (in and out) so that could be a reason... but I cant se why...
/
My setup was meant to verify that in the new clock domain after the fifo the sound of the EXA was at least unchanged. With the freebies it became inferior in practically any respect. Of course the EXA is a much higher quality source than any recovered from spdif signal has any hope to be.
Hmm, s/pdif is lossless. Period. However, it's not the best timing conveyor in universe.
Do you have more info for this claim?
How did you connect the EXA to the fifo? Did you use the isolator board to isolate clock & reclocker & dac grounds from the digital input ground? Does exaU2I have the impedance matching resistors on outputs?
Why I am asking - I have looked at the output terminal of the exaU2I (on their web) and well, how to say it, this is probably good enough for connecting a relay but not a high frequency digital signal. So it is hard to say what is the digital signal quality that is passed to your dac.
I would not like to start a flame war but I think that it would be fair to Ian's work to use the same professional and detailed approach as he is using, when posting judgements.
analog_sa, it seems you are stuck in the 90's-00's when the recovered spdif clock actually meant something? the recovered spdif clock is not used with fifo, it is discarded altogether, not reclocked. so your statement doesnt make a great deal of sense and as shown, it was the spdif input reclocked, with the generic clock, to have less than 5ps.
your subjective opinion is just that, a subjective opinion; which you are welcome to, but making statements like the above based on it.... sorry but it holds no water whatsoever
your subjective opinion is just that, a subjective opinion; which you are welcome to, but making statements like the above based on it.... sorry but it holds no water whatsoever
of course notpopolvar said:
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it is an issue when its being used directly, as with some designs, particularly when it is being used directly with BCK as the only clock...
also just because its horrible jitter can be fixed, as it can here with fifo, doesnt cure it of its sins. not all designs have a proper reclocking stage, some use separate MCK and the rest of the lines directly from xmos. in any measure 2.5nS is HUGE 100-1000x higher than any of the devices that were claimed as horrible digititus inducing audio nightmares. some of those same people have been using the 2.5nS output without reclocking and claiming how 'liquid' and 'organic' sounding it is....
proper reclocking is not included in its reference design is it?
umm, no youve got it backwards, the higher speed xo fs noise is LESS audible than the lower. you dont here the noise, you hear its effect in the time domain. so actually 50-200Hz is the most sensitive region, because it is in this area that dacs, the clock and other parts of the circuit have their lowest PSRR
both the opt and coaxial have the same problem, lock LED "on" without sound from BIII. The FIFO "empty" On. I have used other DAC to confirm the opt source has music.
XMOS reference design reclocks only the SPDIF signal, not the I2S.
But my question remains, do you believe that the proper and/or unique point for perfect timing accuracy should be at the chip that "translates" USB data to I2S signals?
Have you measurements of other similar USB to I2S solutions?
The existence of non-optimum implementations is the whatever chip to blame or the designer of the implementation?
[Another issue is how much the jitter in I2S signal affects the performance of various DACs, are all affected the same way and in the same magnitude?]
My point is to concentrate on the complete design of a system and not on the individual components.
There are devices, out there and in this forum, that prove that good designs do give excellent results even with "problematic" components.
oh I agree on the whole system approach, but the fact the reference design does not call for it and thus has 2.5ns jitter on its output is quite atrocious. they do not make it clear that you should expect this much jitter and take precautions, so there will be MANY xmos based designs that simply reclock MCLK and leave the other chaos intact. 2.5ns is massive, it never would have been accepted even on a recovered spdif clock.
the reference design has an MCLK, so it is not unreasonable to expect the MCLK and i2s to be worth using... hell from my brief glance at the materials they use it directly on their ref designs that have multichannel dac output....
there is nothing saying, btw the i2s has 2.5ns jitter, best you finish the job for us...
the reference design has an MCLK, so it is not unreasonable to expect the MCLK and i2s to be worth using... hell from my brief glance at the materials they use it directly on their ref designs that have multichannel dac output....
there is nothing saying, btw the i2s has 2.5ns jitter, best you finish the job for us...
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If "EMPTY LED" is on that means the I2S signal is wrong. Did it work before? Please see the signals by a scope to find out what's wrong with the I2S.
Ian