Yes I saw the Danish one too. But all the ones that you highlight do not seem to allow an external 5V power supply to be connected, which for some (not me actually) would be an issue.
Of course, with all these things it is experience of actually trying them that is most valuable and Ryelands has given us his feedback and upcoming with his new WaveIO and USB isolator will be most interesting.
having some problems with waveio -> opus i2s.
I'm running out of ideas on where to look to get music flowing through my waveio and opus. Here is a list of scenarios I have tried so far trying to find the source of my problem(s). In each of the tests below I get squelch/hard electronic noise at the output (headphones at this stage, tried 2 different pair of cheap headphones).
I have 2 TPA Opus dacs here - I'll call them Opus A and Opus B. B is one that I have butchered removing the screw terminals (I purchased both second hand and previous owner mounted all of the screw terminals). A still has the screw terminals in place.
So far I have tried:
1. isolated i2s to Opus A to BAL-SE 'The Wire' - waveio powered by usb, isolator powered from sjostrom super reg.
2. non isolated i2s to Opus A with 10cm u.FL leads to BAL-SE 'The Wire' - waveio powered by usb from laptop (laptop running off battery)
3. non isolated i2s to Opus A with 10cm u.FL leads - waveio powered by sjostrom super reg.
4. non isolated i2s to Opus B with 10cm u.FL leads - waveio powered by usb from laptop (laptop running off battery)
5. non isolated i2s to Opus B with 10cm u.FL leads - waveio powered by sjostrom super reg.
6. non isolated i2s to Opus B with 5cm u.FL leads - waveio powered by usb from laptop (laptop running off battery)
7. non isolated i2s to Opus B with 5cm u.FL leads - waveio powered by sjostrom super reg.
In each of 2 - 7 I have tested for connectivity from signal the pad of the u.FL connector to the terminal at Opus and in some cases to via on the opus to ensure connectivity through the headers etc. These tests showed up 0.2 - 0.3ohm. I also checked that the bar tieing all the grounds together had connectivity to the ground at the case of the u.fl connector at the waveio end.
Since the result is the same whether signal passes through BAL-SE 'The Wire' headphone amp or if headphones connected straight to output of the Opus DAC I have decided that the problem is not the headphone amp.
Since the result is the same regardless of usb or external power or isolated i2s I have concluded that the most significant problem is not a ground loop (though at this stage I'm not sure if one exists or not in any of the scenarios listed).
Since the result is independent of which DAC board I connect I've decided the problem is not the DAC. I've tripple checked the jumper settings on the opus board.
With those two possibilities excluded I have decided that the problem is the i2s connection OR both the DACs I bought are duds since they're second hand and I have no other i2s source I have no way to verify that at this stage.
I've attached some photos from while I was using 10cm u.fl leads with Opus A, they aren't the best photos, will try to get a few more later.
I'm running out of ideas on where to look to get music flowing through my waveio and opus. Here is a list of scenarios I have tried so far trying to find the source of my problem(s). In each of the tests below I get squelch/hard electronic noise at the output (headphones at this stage, tried 2 different pair of cheap headphones).
I have 2 TPA Opus dacs here - I'll call them Opus A and Opus B. B is one that I have butchered removing the screw terminals (I purchased both second hand and previous owner mounted all of the screw terminals). A still has the screw terminals in place.
So far I have tried:
1. isolated i2s to Opus A to BAL-SE 'The Wire' - waveio powered by usb, isolator powered from sjostrom super reg.
2. non isolated i2s to Opus A with 10cm u.FL leads to BAL-SE 'The Wire' - waveio powered by usb from laptop (laptop running off battery)
3. non isolated i2s to Opus A with 10cm u.FL leads - waveio powered by sjostrom super reg.
4. non isolated i2s to Opus B with 10cm u.FL leads - waveio powered by usb from laptop (laptop running off battery)
5. non isolated i2s to Opus B with 10cm u.FL leads - waveio powered by sjostrom super reg.
6. non isolated i2s to Opus B with 5cm u.FL leads - waveio powered by usb from laptop (laptop running off battery)
7. non isolated i2s to Opus B with 5cm u.FL leads - waveio powered by sjostrom super reg.
In each of 2 - 7 I have tested for connectivity from signal the pad of the u.FL connector to the terminal at Opus and in some cases to via on the opus to ensure connectivity through the headers etc. These tests showed up 0.2 - 0.3ohm. I also checked that the bar tieing all the grounds together had connectivity to the ground at the case of the u.fl connector at the waveio end.
Since the result is the same whether signal passes through BAL-SE 'The Wire' headphone amp or if headphones connected straight to output of the Opus DAC I have decided that the problem is not the headphone amp.
Since the result is the same regardless of usb or external power or isolated i2s I have concluded that the most significant problem is not a ground loop (though at this stage I'm not sure if one exists or not in any of the scenarios listed).
Since the result is independent of which DAC board I connect I've decided the problem is not the DAC. I've tripple checked the jumper settings on the opus board.
With those two possibilities excluded I have decided that the problem is the i2s connection OR both the DACs I bought are duds since they're second hand and I have no other i2s source I have no way to verify that at this stage.
I've attached some photos from while I was using 10cm u.fl leads with Opus A, they aren't the best photos, will try to get a few more later.
Attachments
Yep the LED turns on - photo was taken when everything was powered down.
BRD is correct. EXT uses the usb header rather than the USB socket mounted onboard.
In other news I played with the midi settings in OSX - flicked it back to 44.1kHz rather than 192k and I get nothing but music out of the headphones. Now I need to re-connect the headphone amp and set myself up for dual mono. After far more hours spent looking at this stuff than I care to admit for it to be a software problem in the end is thoroughly frustrating but I'm sure that will all be forgotten soon enough!
BRD is correct. EXT uses the usb header rather than the USB socket mounted onboard.
In other news I played with the midi settings in OSX - flicked it back to 44.1kHz rather than 192k and I get nothing but music out of the headphones. Now I need to re-connect the headphone amp and set myself up for dual mono. After far more hours spent looking at this stuff than I care to admit for it to be a software problem in the end is thoroughly frustrating but I'm sure that will all be forgotten soon enough!
I'm not an expert but from what I've read best practice is to keep the signal and return (gnd) path as close as possible. This is what would happen if it was properly terminated at the DAC end with a u.FL connector. Sending the gnd connection back to H4 probably increases chances of ground loops and noise being picked up by the cables.
Hi Hochopeper
I have my WAVEIO/Teleporters/Buffalo3 grounds connected pretty much as you describe above with no problems.
Just a wild stab
But I could be worth disconnecting your u fl cables and doing a continuity test to check for shorts.
Those skinny cables would just need a nick to short one which is easily done and hard to spot.
You’ve probably tried this already but just to be sure.
Good luck
I hope it sorts out soon.
Hi Hochopeper
I have my WAVEIO/Teleporters/Buffalo3 grounds connected pretty much as you describe above with no problems.
Just a wild stab
But I could be worth disconnecting your u fl cables and doing a continuity test to check for shorts.
Those skinny cables would just need a nick to short one which is easily done and hard to spot.
You’ve probably tried this already but just to be sure.
Good luck
I hope it sorts out soon.
Thanks shoom, I wasn't very clear earlier, but I've fixed it! Was a setting on the computer that seemed to be causing the problem.
On a side note its probably worth noting for other waveio users that you don't need to remove the u.fl cable from the receptacle to check for connectivity or shorts. The u.fl receptacle has a 3 pad pattern on the pcb. The single small pad at the front of the connector is the signal. The two longer pads on the sides are connected to ground on the waveio. Even when there is a cable connected you can get a multimeter at the signal pad without disconnecting the u.fl cable!
These micro coax cables have a limited number of connect/disconnect cycles that they last for, saving any unnecessary activity on these is worthwhile.
Page 3 of this datasheet shows the hirose u.fl landing pattern.
Thank you for this valuable info. I completely missed it. 30 cycles are a very few indeed.
Ryelands has helped me change my thinking about control for the Wolfson DACs. They need not allow external power so the following post was incorrect.
When using the WM8740, one needs SPI rather than i2c but the 8741 accepts either. The Diolan line of interfaces seem well suited, allowing either i2c or SPI together with enough GPIO to read WaveIO status and provide chip select for dual mono opus. ADum140x isolation for 12 bits between Diolan and WaveIO is better than USB isolation in this case but because of the added jitter, ADum4160 USB isolation is probably superior between PC and WaveIO.
When using the WM8740, one needs SPI rather than i2c but the 8741 accepts either. The Diolan line of interfaces seem well suited, allowing either i2c or SPI together with enough GPIO to read WaveIO status and provide chip select for dual mono opus. ADum140x isolation for 12 bits between Diolan and WaveIO is better than USB isolation in this case but because of the added jitter, ADum4160 USB isolation is probably superior between PC and WaveIO.
Measurements?
"Quote: (from Spencer)
How does the measurements compare to the XMOS reference design? I means at SPDIF out and I2S out? Any graph comparison is good especially on Jitter and noise figures. If possible, please show how the test is conducted and equipment used.
Thank you
reply: (from Lorien)
When I'll have the required informations I'll post them asap. For now, there are two members of this forum which could do noise and jitter tests and I'm still waiting an answer."
This was posted almost a year ago, in June 2011. Has anyone posted measurements? I have searched this thread and I haven't been able to find them. If they are available, could someone post a link? I am very interested in seeing the jitter measurements of the WaveI/O and the XMOS Reference Design. I found these measurements of the Reference Design, in case anyone is interested.
Thanks!
Aaron.
"Quote: (from Spencer)
How does the measurements compare to the XMOS reference design? I means at SPDIF out and I2S out? Any graph comparison is good especially on Jitter and noise figures. If possible, please show how the test is conducted and equipment used.
Thank you
reply: (from Lorien)
When I'll have the required informations I'll post them asap. For now, there are two members of this forum which could do noise and jitter tests and I'm still waiting an answer."
This was posted almost a year ago, in June 2011. Has anyone posted measurements? I have searched this thread and I haven't been able to find them. If they are available, could someone post a link? I am very interested in seeing the jitter measurements of the WaveI/O and the XMOS Reference Design. I found these measurements of the Reference Design, in case anyone is interested.
Thanks!
Aaron.
Well...
Measuring jitter is not a trivial matter. Very few people have the equipment and expertise to accurately measure jitter levels, and provide an actual jitter spectrum plot. Additionally, comparing jitter measurements can be a real problem: only measurements using the exact same equipment and methodology should be used for actual comparisons. Also, becuase the WaveIO is a DIY product, how it is implemented will also effect the output jitter levels (power supply, I2S wiring, perhaps even the USB cable and computer source), so jitter levels/spectrum and clock phase noise may all vary somewhat with different implementations.
I would love to see some measurements (hopefully on a WaveIO with the NDK oscillators), but the only comparisons which I would be willing to suggest coiuld be valid, were measurements taken with the exact same approach.
Measuring jitter is not a trivial matter. Very few people have the equipment and expertise to accurately measure jitter levels, and provide an actual jitter spectrum plot. Additionally, comparing jitter measurements can be a real problem: only measurements using the exact same equipment and methodology should be used for actual comparisons. Also, becuase the WaveIO is a DIY product, how it is implemented will also effect the output jitter levels (power supply, I2S wiring, perhaps even the USB cable and computer source), so jitter levels/spectrum and clock phase noise may all vary somewhat with different implementations.
I would love to see some measurements (hopefully on a WaveIO with the NDK oscillators), but the only comparisons which I would be willing to suggest coiuld be valid, were measurements taken with the exact same approach.
I suppose that the only lab that can do this is Audioreview's lab ( it is an italian magazine where I have a collaboration)
In this lab there is an Audio Precision 5xxx family; Fabrizio Montanucci, the technical director, fix two specific tests: periodic jitter and stocastic jitter.
Very interesting!
Now I have ready a dac with Buffalo II dac , with Lorien board connected in I2s; the output is tube with a Sowter 3565 trafo from dac to output.
It will be measured in next days because I am trying to write an article on it
Bye
Walter
In this lab there is an Audio Precision 5xxx family; Fabrizio Montanucci, the technical director, fix two specific tests: periodic jitter and stocastic jitter.
Very interesting!
Now I have ready a dac with Buffalo II dac , with Lorien board connected in I2s; the output is tube with a Sowter 3565 trafo from dac to output.
It will be measured in next days because I am trying to write an article on it
Bye
Walter
Question...
Are you going to have the jitter measured as a product of the analog output of the entire DAC (how John Atkinson at Stereophile measures it?). If so, remember that the B-II has an onboard masterclock which re-clocks everything in the ASRC of the ESS chip, so this type of measurement will not be measuring the WaveIO, but instead, the B-II (unless you set your B-II up for synchronous operation by defeating the onboard oscillator and feeding it masterclock from the WaveIO).
It would be interesting to see jitter measurements of the direct I2S feed from the WaveIO, and to compare the isolated and non-isolated outputs. I believe the Wavecrest Analyzer is the right tool for this measurement (please those who know something about really measuring relevant aspects of jitter feel free to educate us)?
Are you going to have the jitter measured as a product of the analog output of the entire DAC (how John Atkinson at Stereophile measures it?). If so, remember that the B-II has an onboard masterclock which re-clocks everything in the ASRC of the ESS chip, so this type of measurement will not be measuring the WaveIO, but instead, the B-II (unless you set your B-II up for synchronous operation by defeating the onboard oscillator and feeding it masterclock from the WaveIO).
It would be interesting to see jitter measurements of the direct I2S feed from the WaveIO, and to compare the isolated and non-isolated outputs. I believe the Wavecrest Analyzer is the right tool for this measurement (please those who know something about really measuring relevant aspects of jitter feel free to educate us)?
The Wavecrest is a useful tool but not the best for this type of measurement. You are looking for the phase noise spectrum to get any real information. That is very closely related to the plots published in the Stereophile. The Wavecrest looks at the cycle to cycle spread of the master clock and essentially analyses its variations. It also measures across the entire hf spectrum. Its much less sensitive to low frequency variations however.
The most accepted way to measure the phase noise of the clock is using a phase locked reference clock and a double balanced mixer along with a low noise amplifier etc. into an audio spectrum analyzer. You need a really good reference clock, which can be difficult to find or really expensive. There are several tools for converting the measured phase noise into jitter. Phase noise above 2X the sample rate will not contribute to jitter in the output. There are a lot of questions about the audibility of low frequency phase noise since its contribution is attenuated by the process and peoples sensitivity to pitch modulation is well documented (from tape and disk studies) and way higher that anything from these processes.
The important thing to look for is deterministic jitter, the specific identifiable tones that come through. These can be much higher than the random jitter and may be audible at much lower levels.
While its interesting to see what jitter is in the clock its more meaningful to see what comes through to the output of the system, since this is the cumulative effects of all the jitter mechanisms upstream. ASRC's can remove some jitter problems but they will also permanently imbed others into the stream.
The most accepted way to measure the phase noise of the clock is using a phase locked reference clock and a double balanced mixer along with a low noise amplifier etc. into an audio spectrum analyzer. You need a really good reference clock, which can be difficult to find or really expensive. There are several tools for converting the measured phase noise into jitter. Phase noise above 2X the sample rate will not contribute to jitter in the output. There are a lot of questions about the audibility of low frequency phase noise since its contribution is attenuated by the process and peoples sensitivity to pitch modulation is well documented (from tape and disk studies) and way higher that anything from these processes.
The important thing to look for is deterministic jitter, the specific identifiable tones that come through. These can be much higher than the random jitter and may be audible at much lower levels.
While its interesting to see what jitter is in the clock its more meaningful to see what comes through to the output of the system, since this is the cumulative effects of all the jitter mechanisms upstream. ASRC's can remove some jitter problems but they will also permanently imbed others into the stream.