Wowza - how did I missed that? Downloading now...
Then let me (and others) beta test it
Virtins Multi-Instrument 3.9 does it too.For multiple tones you need a measurement function that removes all stimulus tones from the FFT result. The remaning rest is Total Distortion plus Noise, TD+N (not THD+N). Not sure REW supports this at all. AP does.
Technical Library
www.ap.com
We might need another test that looks at the skirt and close-in sidebands vs. zero signal noise: Notch out the fundamental and all harmonics very narrow-band using the inverse envelope of the window function (plus some margin) to truncate the skirt as little as possible. Identical idea to what is used for multi-tone TD+N values.Skirting caused by random jitter is typically included in the fundamental when calculating THD+N while distinct spurs count as noise.
Even by that measure, SRC4192 is excellent. Benchmark uses 4392 which has the exact same ASRC core.There's also the jitter aspect which that figure doesn't take into account.
Hi @mansr ,
do you think that this board would work to generate to MCLK , then sending the 4 signal to another board converting I2S (with MCLK this time) to SPDIF/AES ?
View attachment 160699
The point that I'm not sure how to handle it is the constant output of 211kHz :
Chipset: CS8421Input Sampling Rate: Up to 192kHz (16 / 32Bit)Constant Output Sampling Rate: 211kHzPower Supply: 5V DCI suppose that it's due to the 27MHz chip, so would it possible to replace it with a 24.576 one ?
EDIT : just found one with a 24.576 chip :
aliexpress.com/item/33035364226.html
View attachment 160700
or this one :
View attachment 160701
First time I see this listed there. I wonder what this Grade 0 actually means, as it's not listed on their webpage (https://e1dashz.wixsite.com/index/cosmos-adc).Grade 0..
139.0US $ |E1DA Cosmos ADC Hi Precision Analog To Digital Converter For Audio Testing Bundle 1=Grade C Bundle 2=Grade B Bundle 3 =Grade A|Digital-to-Analog Converter| - AliExpress
Smarter Shopping, Better Living! Aliexpress.comwww.aliexpress.com
The item page has it:First time I see this listed there. I wonder what this Grade 0 actually means, as it's not listed on their webpage (https://e1dashz.wixsite.com/index/cosmos-adc).
SNR=DR@MONO:
129db(A) and better Grade-0
For those of you that have a Cosmos ADC (I don't... yet) could somebody run AlexCP's 7kHz+13kHz 1:1 twin-tone with REW (using separate DAC channels mixed together passively)? I found this one the most revealing twin-tone as it tests for loop gain around 20kHz, too bad it's not a standard, yet (see this post and following posts).
REW provides TD+N for multitone and TD+N along with the various IMD figures for two and three tone signals, but only when using REW's signal generator - that way it knows what the test signal is.For multiple tones you need a measurement function that removes all stimulus tones from the FFT result. The remaning rest is Total Distortion plus Noise, TD+N (not THD+N). Not sure REW supports this at all. AP does.
Technical Library
www.ap.com
REW provides TD+N for multitone and TD+N along with the various IMD figures for two and three tone signals, but only when using REW's signal generator - that way it knows what the test signal is.
That board does USB to/from other interfaces. If what you want is an S/PDIF output from the Cosmos, that will not help.XMOS Multichannel high-quality USB to/from I2S/DSD SPDIF PCB 3W
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Do you think I can do the function I want with this board?
Yes, as long as the external signal has the same characteristics as the one selected in the REW generator. Easy enough for dual tone, but could be tricky for multitone, need identical bin choices.If I have the generator running with the right multi-tone setting outputting to some null device while feeding RTA data from an non-REW source, it should then measure the distortions correctly, yes?
Yes, as long as the external signal has the same characteristics as the one selected in the REW generator. Easy enough for dual tone, but could be tricky for multitone, need identical bin choices.
It's so hard...That board does USB to/from other interfaces. If what you want is an S/PDIF output from the Cosmos, that will not help.
The various ASRC based boards mentioned above will work if a slight degradation of the signal is tolerable.