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Old 8th July 2012, 08:27 AM   #971
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Hooked an Exa board in place of the WaveIO. PCM1794 locks fine at all sampling rates now. Is it possible i may be having a defective oscillator? Any ideas how to test without a frequency counter?
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Old 8th July 2012, 08:52 AM   #972
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Quote:
Originally Posted by ed linssen View Post
Hi Pepe,

Could you share your changes to the standard Placid HD to get the 750mA?
Thanks in advance,
Ed
Ed,

The placid I have is the 2.0 version, no the HD. I just replaced the VR2 pot with a bigger value one (if I recall correctly) and the unit is able to provide 750miliamps without any problem.

There is a thread in the Twistedpear support forum talking about the HD and if my memory serves me well, Russ said that you won´t have any problem on getting 750 miliamps with the HD as long as you provide the right trafo and maybe doubling the primaries. Make sure of providing bigger heat sinks though.

best regards
Pepe
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Old 8th July 2012, 12:06 PM   #973
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@ pinnocchio & analog_sa:
Like ENSen said, try to use a short USB cable! There could also be a problem if you use isolated I2S port and vreg used to power it is at a considerable distance from the NVE chip. I do not get into technical details of what "considerable distance" might be I simply suggest to place that 3.3V reg as close to the V+ and "Isol.GND" pins as possible. In addition, you could add few bypassing caps as well, it's obviously that C6 cap is simply NOT enough...

@ analog_sa: I do not contest that 22.5792 MHz oscillator could be defective... still, it's hardly for me to believe. My testing procedures implies using a PCM1794-based DAC board which uses Isolated I2S outputs and an oscilloscope. Tests are run by playing the same song (at each sample rate from 44.1 to 192 kHz) and while I listen the music, I check the signals with my scope. ALL the I2S signals. In parallel, my scope shows up the peak-to-peak voltages and freq of I2S periodic signals (including I2S Master Clock Signal which depends on incoming sample rate: 22.5792 MHz or 24.576MHz).
If all is okay then I leave the board playing a song for over two hours, continuously, searching for anything that is not "music".
I would suggest you to try and move closer your external 3.3V PSU used to power up the isolator (if you're using Isolated I2S output) If there are still problems with your card then please send it back to see what's wrong with it. Just let me know and I'll send my addres in a PM.

Kind regards,
L
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Contact link for WaveIO USB-to-I2S/SPDIF board.
Daughter card GB list for WaveIO can be found here

Last edited by Lorien; 8th July 2012 at 12:07 PM. Reason: speeling
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Old 8th July 2012, 01:05 PM   #974
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Quote:
Originally Posted by Lorien View Post
@ analog_sa: I do not contest that 22.5792 MHz oscillator could be defective... still, it's hardly for me to believe.
And you are most likely correct. For some reason getting this to work with the 9018 took five minutes and i have already spent a day messing with an old 1794 board... must be cursed. First it was the 5cm extension between the usb header and panel mounted usb connector. Learnt the hard way that those 5cm better be screened.

Clock switching now seems to be working. There is an oscillator on the 1794 board @24.576MHz. Its output wasn't connected any more but now i've cut power to it and all seems fine. Not sure if some such interference is at all possible, or it was something random. Will redo carefully all wiring and especially the MCLK.

On the plus side, sound with the 1794 is very good indeed and considerably better than when the asrc was in use.

Thanks for the fast reply and sorry for the disturbance.
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Old 8th July 2012, 07:32 PM   #975
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Interestingly, i haven't seen much discussion here about the driver settings. On my PC there is a very pronounced difference in sound when driver is set for minimum latency. Unfortunately wireless then has to be switched off but the sound gets remarkably better, nearly approaching that of Exa. I guess a fully optimised PC source will be even better.
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Old 8th July 2012, 08:30 PM   #976
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Hi Pepe,
Thanks for your reply. I myself have a HD version. No problem to get as high as about 600! Did not try higher though! The only problem is the heat than. At lower res. the WaveIO takes a lot less current. Three to four hundred. That includes a rather high shunting. So bigger heatsinks should be the right solution indeed, in my case as well,
Ed

Last edited by ed linssen; 8th July 2012 at 08:33 PM.
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Old 10th July 2012, 01:37 PM   #977
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Hi,

Someone can give me the reference of the femelle connector to plug an usb cable to the 1x5 male header on thee board please ? I search on radiospare but I have difficulty to search for this specific connector, what is the name ? Or better, if someone has a ref for the usb cable withe this connector (I found someting in computer shop but it is 40cm, a bit long for my dac).

Thanks.
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Old 11th July 2012, 08:33 AM   #978
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Quote:
Originally Posted by analog_sa View Post
Interestingly, i haven't seen much discussion here about the driver settings. On my PC there is a very pronounced difference in sound when driver is set for minimum latency. Unfortunately wireless then has to be switched off but the sound gets remarkably better, nearly approaching that of Exa. I guess a fully optimised PC source will be even better.
Yep. That's a pity. Even though XMOS is one of the newest designs it doesn't manage to suppress PC induced timing variations. (noise should be covered by the Wave-IO isolator - and signals are locked !?!?)

EXA with its proprietary driver might have those issues a little better under control.

I'm wondering if Ian's reclocker hooked up to the WAVE-IO, would make "the difference". Anybody tried that???

The Tenor chip + DSP reclocker of my Audio-GD DI makes a difference.

The ultimate goal should be to achieve the same sound with whatever PC setup as long as signal is locked and no XRUNS occur.

I'm still looking for such a design. Perhaps Wave-IO V2 gets a bit closer.
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Old 11th July 2012, 09:33 AM   #979
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I have the Wave now and am in GBII, so will find out soon enough!
I am running Linux which wlowes who was running cmp2 is now running and he says the Linux is a step up in sq.
Looking to isolate the source as well so they reduce/remove relevance.

Will keep in touch soundcheck and advise findings.
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Old 11th July 2012, 02:38 PM   #980
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Quote:
Originally Posted by PET-240 View Post
I have the Wave now and am in GBII, so will find out soon enough!
I am running Linux which wlowes who was running cmp2 is now running and he says the Linux is a step up in sq.
Looking to isolate the source as well so they reduce/remove relevance.

Will keep in touch soundcheck and advise findings.
Hi.

I opened a thread over here in 2007 called "Linux Audio the way to go". I always claimed that my setups sounded better then Cics Cplay/CMP2
setups. Cics was not the one who has been starting the whole run btw.
It told him 20 times that he'd bet on the wrong system.

However.

When it comes to PC transports, the SB Touch is a Linux system with real time kernel asf. IMO better then a CMP2 from a HW perspective.
By using the EDO plugin you can run nicely USB DACs up 192khz with it.
Try to get an "audiophile" PC up'n running at 250$. No way.

However. After all those years there's not much progress in the audio interface area. I'm not aware of any commercial device which wouldn't
respond to transport related optimizations.That's pretty frustrating.

What we've seen so far is that tweaking the transport will never end.

Unless somebody builds an audio interface that does the job right.

Cheers
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