I mean, we are talking insane measurement-grade performance here, so yeah.Wow this starts to be like the equipment at work, switch on and wait 2-3 hours until it stabilizes![]()
I juste measured my E1DA Cosmos ADC 'A-Greade' with REWusing SMSL M400 (AK4499EQ) as a signal source. In mono mode it shows THD+N below -121dB! Worst harmonics stays around -140dB
To be honest, this is first time I see such a values at home. Thank You Ivan
View attachment 173192
Do you calibrate at 27°C of room temperature with the aluminum case of the Cosmos ADC being pretty much at 27°C? This seems pretty hot, but may be customary where you are. How hot does the ADC chip's case surface get when the aluminum case is at 27°C?ChUmI, well, I do design only what I like to use. Nobody design a decent ADC for audio measurement for $100-200 , hence, I have to do that
BTW, not all 100% of Cosmos ADC has 3rd harmonic as low as -140db. Average is -138db, worst ADC unit had -134db, the best one -145db or less but it is rare.
Be aware, that 3rd harmonic noticeable depends on the ADC temperature, so try to keep it warm(I calibrate ADCs at 27C). Very soon I'll offer a tiny thermostat PCBA for ES9822 chip, which will keep the ADC chip temperature around 50C, if the ambient is too cold. The PCBA is 5x5mm heater with a thermometer onboard. To install the thermostat need to glue that on the top of ES9822 IC, and connect two wires 5VDC and GND.
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You can plug unbalanced sources into the Cosmos pretty easily.Hi @IVX any plans for an unbalaced simple USB ACD? I bet there is a market for it.
People is using musicians interfaces with lots of innecesary functionality to just digitalize their records or stuff like that, but simple, small and decent ADCs aren't common.
Definitely a niche product but you would be the only one in the market i think...
you can consider Cosmos ADC as unbalanced with no mistake, there is FDA input, hence, doesn't matter balanced or unbalanced source you need to convert. I don't believe if someone may complain that Cosmos ADC is a too big device(103x61x39mm .15kG). Or you are talking about a dongle-sized ADC??Hi @IVX any plans for an unbalaced simple USB ACD? I bet there is a market for it.
People is using musicians interfaces with lots of innecesary functionality to just digitalize their records or stuff like that, but simple, small and decent ADCs aren't common.
Definitely a niche product but you would be the only one in the market i think...
Ok, from this I gather that at 27°C box temperature the ADC chip's case lives near 50°C already so that taking it up by a few degrees won't matter for calibration (probably not true, see addendum).capslock, the temperature of the thermostat selected to have no problem with recalibration. Just need to glue that to the ADC chip and tie 2 wires.
ES9822 uses so-called polyresistors which have minimal nonlinearity at such a temperature. 10C will create a lot more distortions.
Looks great!I juste measured my E1DA Cosmos ADC 'A-Greade' with REWusing SMSL M400 (AK4499EQ) as a signal source. In mono mode it shows THD+N below -121dB! Worst harmonics stays around -140dB
To be honest, this is first time I see such a values at home. Thank You Ivan
View attachment 173192
is your room temperature 23C? I guess so.dac : e50 xlr, 0dbfs
adc : cosmos adc 4.5v
rew : -1dbfs
View attachment 173483Tested how it changes with temperature.
Yes. How did you know? between 23~24.is your room temperature 23C? I guess so.
Hi, missed you post some weeks ago. It looks like you succeeded with a raspberry board, well done!Sure, I use a hifiberry beocreate DSP board (just because I had it lying around) which has an analog devices ADAU1451 DSP and decent power supplies onboard.
I connect the Cosmos with I2S to the DSP board (I abuse the RPI pins for this)
The DSP can have the Cosmos as clock master or can use onboard samplerate convertors.
The Board has spdif in TOSLINK out (only goes up to 192kHz but thats fine for me), which I connect to my RME babyface pro
Grooved, to be honest, I don't care about the studio-production market, there is brand-name needed but not tech specs. If you are The Name, you can sell the same model for 15 years for $2000-4000/pcs with THD+N -115db, and Crosstalk -115db as a TOP of technology. I have sold about 2000pcs DACs with THD calibration ability, Cosmos ADC for that. I think if someone in a modern studio aren't stupid, he'll buy my Cosmos for 10% of The Name price, maybe 10-50pcs of ADCs would be sold there, why I should care?
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Business managers make poor engineers. And engineers make poor business managers. Me thinks you should hire a business manager in your country Ivan!