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trl

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#21
@amirm I wonder if you took some time to do a short test of this EVM. I was wondering how the jitter looks like, but also if it would be a good ADC for testing audio devices. From the graphs above the background noise seems very low, at least for freqs above 1KHz, which are the most interesting actually.

Thank you!
 
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#25
So the number 1 place in the whole list is
Forssell MDAC-4 ----> Focusrite Blue 245 master
Focusrite sensitivity 0 dBFS = 20 dBu, serial number = 10
4.0 dB (L), 4.0 dB (R) Corr Depth: 66.9 dB (L), 69.8 dB (R) Difference*: -81.2 dBFS (L) -81.1 dBFS (R)

And the number 2 is this:
SPL Madison ---> Texas Instrument PCM4222 Evaluation Module master (living sounds). Details of the clocking., DC filter off.
0,2 dB (L), 0,2 dB (R) Corr Depth: 78,7 dB (L), 81,2 dB (R) Difference*: -80.1 dBFS, -80.1 dBFS
 

Blumlein 88

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#26
So the number 1 place in the whole list is
Forssell MDAC-4 ----> Focusrite Blue 245 master
Focusrite sensitivity 0 dBFS = 20 dBu, serial number = 10
4.0 dB (L), 4.0 dB (R) Corr Depth: 66.9 dB (L), 69.8 dB (R) Difference*: -81.2 dBFS (L) -81.1 dBFS (R)

And the number 2 is this:
SPL Madison ---> Texas Instrument PCM4222 Evaluation Module master (living sounds). Details of the clocking., DC filter off.
0,2 dB (L), 0,2 dB (R) Corr Depth: 78,7 dB (L), 81,2 dB (R) Difference*: -80.1 dBFS, -80.1 dBFS
A notable thing about these results are the very best results are when you have a one device clocking another device. You would think loopbacks would clock even better. Same clock used for both ADC and DAC. However, there is a small time delay caused by the signal leaving the DAC, traveling over the cable, and getting to the ADC. A few nanoseconds. You get lesser results if you have a master clock clocking both devices, and I think for that same reason. If the DAC clocks the ADC, then the clock signal also travels over a cable between devices and the clock between the DAC and ADC can be much closer to the same timing on the signal at both ends. Which means the nulling software has a much easier job time aligning everything.

I suspect the Diffmaker software limits how well it can match up the timing. So some devices in pure loopbacks probably are actually doing better, but the offset timing interferes with results.

And anyone interested in this, you really owe it to yourselves to get Pkane's Deltawave software. It does what Diffmaker does, only better, without blowing up all the time and with many useful features. You can get it for free here (Windows only):

https://deltaw.org/

It is up to revision 45.

PS-I've submitted a few results to that gearslutz thread, and Deltawave gave results within a db or 2 of Diffmaker. More recent versions usually give better results by just a bit. Plus Deltawave is so much more nicely featured.
 
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#27
Yes, that's also a very strange thing, I don't understand why. The wav file are all linked in the table, so it'd be quite easy to re-evaluate for example a RME ADI-2 Pro loopback in Deltawave today.
 

Blumlein 88

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#28
Yes, that's also a very strange thing, I don't understand why. The wav file are all linked in the table, so it'd be quite easy to re-evaluate for example a RME ADI-2 Pro loopback in Deltawave today.
Left and then right channel. Showing in this case is the spectrum of the difference in the original and the Madison_EVM file.
1569898887754.png


1569898995250.png
 
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#30

trl

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#31
I will have to dig it up and get it working again. My backlog is pretty deep now so if you don't mind, remind me in a few weeks to test it.
I found two interesting articles: http://s3t.it/measurements/pcm4222evm/ with few measurements and http://www.dimdim.gr/2015/04/the-texas-instruments-pcm4222-evaluation-board/ with the AES to SPDIF adapter (original source here: https://www.rane.com/note149.html).

Nevertheless, MiniDSP USBStreamer seems to be a wise choice to connect the USB port of a PC to the PCM4222EVM.
 

pkane

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#32
@Blumlein 88 which values from the screenshot match the Diffmaker ones?
Difference (rms) is the difference value, Correlated null is the correlation depth:
1570031472155.png


Here's the same comparison from Gearslutz using DiffMaker (and a Matlab script):
Difference*: -80.1 dBFS, -80.1 dBFS Corr Depth: 78,7 dB (L), 81,2 dB (R)
 

Blumlein 88

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#33
@Blumlein 88 which values from the screenshot match the Diffmaker ones?
The difference RMS. Uncorrelated nulls are determined a bit differently in Diffmaker vs Deltawave so they aren't directly comparable. Though usually show a similar value.

Oops, just saw Pkane answered. He wrote the software. Very nice and has many extra features.
 
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