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Old 29th January 2013, 02:18 AM   #1611
1audio is offline 1audio  United States
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Here is the app note: http://www.akm.com/AppsNotes/AN120516.pdf

If you want to go down this road I'll follow along. I have no time to do it myself but I can get help from AKM if you need it.
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Old 29th January 2013, 02:57 AM   #1612
davada is offline davada  Canada
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Quote:
Originally Posted by 1audio View Post
Here is the app note: http://www.akm.com/AppsNotes/AN120516.pdf

If you want to go down this road I'll follow along. I have no time to do it myself but I can get help from AKM if you need it.
Well not immediately. Down the road. I have to finish current projects before tackling this.
I also have to figure out how to get the data into the computer.

I might be able to funnel it through an EMU 0204 with a bit of mods. It would be nice to have a driver for the maximum sample rate of the 5394A.

The demo board for the 5394 is pretty expensive. The PCB art work is shown in the manual.
Does AKM make PCB file available?
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Old 29th January 2013, 04:18 AM   #1613
Frex is offline Frex  France
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Hello,

I confirm that AK5394 is the lowest THD ADC available. I've made some time ago an ADC box using this IC and no more recent IC allow better THD and lower out of band noise (especially at 192k sampling rate).
I've build also recently another ADC based on the Cirrus CS5381 ADC and i was a little bit dissapointed because results are significantly lower than AK5394.
The fact is that both ADC and DAC IC will no longer interest IC manufacturers. All these IC were made from a long time. I don't know why, and it's a pity...
Actually, i you don't want spend money and time to build your own, probably the better solution is the TI ADC EVM (PCM4222) for 149USD. It's results performances are very good.
I had plan to build an ADC using the AK5388 ADC that have 4 channels, and use a CPLD to increase performance by SQRT(N channels)dB used in parrallel mode.
Unfortunatly, AKM parts are not easy to get (at least in EU) and i don't have so much time right now.
The ESS ES9102 ADC seem also to be interesting, but it exist from about two years and i don't have read any real world specs that it can really reach. I think also that signed a NDA to use an IC is not very DIY friendly !
About AKM and Cirrus ADC, if somebody are interested,i could post my FFT results.
Regards.

Frex
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Old 29th January 2013, 04:27 AM   #1614
RNMarsh is offline RNMarsh  United States
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I am late to the party by about 2-3 years!
Yes, I/we are VERY interested. We need the best there is for measurement uses.
And, I'll look for the PCM4222 as well. Do you or anyone you know have this in a completed package -- maybe from china/internet source?
Thank you... -Richard

Last edited by RNMarsh; 29th January 2013 at 04:35 AM. Reason: Late to the party
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Old 29th January 2013, 05:09 AM   #1615
1audio is offline 1audio  United States
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Richard:
I can lend you my demo board for the TI PCM4222.

I am using an ESI Juli@ card to bring the data into my PC. I use Praxis as my primary go to software solution, mostly because I have it and know how to get a lot from it. However HPW-works or Arta or others are similar. I don't think any of them are nuts enough to include 16M point fft's.

I could lean on ESS to get a demo of the chip but I don't think its worth the effort. The AKM is hard to get but I think its now available at NuHorizons. Its steep as well at $350. It could be simplified a lot into a smaller PCB or use the 4 ch version and make the ultra low noise version. I am game (but not free now) to work on it. I need to finish the QA400 interface first.

The QA400 uses the Cirrus CS4272 CS4272 : 114 dB, 24-Bit, 192 kHz Stereo Codec which seems to be pretty good and a good value but not in the same league.

The Audio Widget has been designed and has support for the AKM 5394A but the current PCB's don't have ADC capability. This would be another way to get the data into a PC. The current version from Q N K T C USB-I2S Module and Analog Board has a pretty decent AKM DAC (higher second harmonic but not enormously than the premium parts) and could be kludged to run the ADC I think. Too many projects, too little time.
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Old 29th January 2013, 05:51 AM   #1616
RNMarsh is offline RNMarsh  United States
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Quote:
Originally Posted by 1audio View Post
Richard:
I can lend you my demo board for the TI PCM4222.

I am using an ESI Juli@ card to bring the data into my PC. I use Praxis as my primary go to software solution, mostly because I have it and know how to get a lot from it. However HPW-works or Arta or others are similar. I don't think any of them are nuts enough to include 16M point fft's.

The QA400 uses the Cirrus CS4272 CS4272 : 114 dB, 24-Bit, 192 kHz Stereo Codec which seems to be pretty good and a good value but not in the same league.
Too many projects, too little time.
I am too far along my Life Line to spend even as much as I have on trying to measure circuit distortion. Running out of time to do everything I want. I am in good health BUT time is getting shorter on this end of it.
I havent been able to figure out the ShibaSoku fft output. it doesnt seem to be there.... maybe why I was able to buy it cheap. Or its just me. I'll play some more with it.
I'd like to try the PCM4222 demo board to measure with but it needs a USB as I dont want yet more kludges to deal with.... that is what is appealing about the QA400... bundled. Ideas? [$350 is ok for AKM if it works as needed] Thx-Richard

Last edited by RNMarsh; 29th January 2013 at 06:03 AM.
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Old 29th January 2013, 06:25 AM   #1617
jcx is offline jcx  United States
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for ADC http://www.analog.com/static/importe...ets/AD7690.pdf looks pretty good with -125 THD/spurs - though only "typical" spec and not a "audio" ADC @400 ks/s 18-bit

Last edited by jcx; 29th January 2013 at 06:44 AM.
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Old 29th January 2013, 06:42 AM   #1618
1audio is offline 1audio  United States
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Richard:
Connect the analysis output to the QA400 input. The distortion spectrum will be displayed with the fundamental at 488.2 Hz. However I know mine works if you want to trade. . .
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Old 29th January 2013, 08:27 AM   #1619
RNMarsh is offline RNMarsh  United States
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Quote:
Originally Posted by dimitri View Post
Richard, you posted 339A measurements in #1580. Can you please mention data for Victor's oscillator? Can you put a load for Victor's oscillator, say 600 Ohm?
It doesnt change much --- from NL it is .000015% and at 600 ohms it is .00002%. (1KHz).
-RNM

Last edited by RNMarsh; 29th January 2013 at 08:32 AM.
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Old 29th January 2013, 11:08 AM   #1620
vicnic is offline vicnic  Latvia
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Quote:
Originally Posted by Frex View Post
Hello,

I confirm that AK5394 is the lowest THD ADC available. I've made some time ago an ADC box using this IC and no more recent IC allow better THD and lower out of band noise (especially at 192k sampling rate).
I've build also recently another ADC based on the Cirrus CS5381 ADC and i was a little bit dissapointed because results are significantly lower than AK5394.
...

Frex
Hi,
Please can you tell little about real performance difference (distortions, noise, artifacts) between AK5394 and CS5381?
Thank you.

Victor
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