Best spec ADC Chip currently.... ??

[boXem]

@IVX I am also very interested. Count on me as a customer.
To be sure that I understand, APU is not for power amps measurements and ADC has no notch, right? If I'm right, a notch post attenuator could be a nice addition to the ADC Pro.
Any timing for the Cosmos DAC?
Will there be a "Cosmos pack" DAC + APU + ADC?

 

[IVX]

boXem | audio, you are right, APU is an extension for really high-precision measurements of DACs. APUs notch has 10Vrms max input level, LNA max level = 10Vrms/100 if +40db gain or /1000 if +60db. So you can measure the noise level of power amps with LNA but for the full-scale power amp output you need some 1/3 resistors divider(I make such things inside of cables) before the notch. However, power amps usually aren't so low-noise and low-distortion devices as modern DACs. BTW, the notch has a 2-positions switchable post gain 0/6db. Cosmos ADC is the plain ADC/USB interface, that's it. We preparing the Cosmos FFT software as well, simple but correctly measuring Cosmos_FFT.exe. The SW will able to control THD compensation coefficients of ES9822 2nd, 3rd, and 5th harmonics, so you can compensate your own Cosmos ADC unit at 10kHz(optimal 1kHz THD compensation isn't matched to 10k) for the minimal distortions, using Cosmos DAC +LPF_10k as a reference sine tone. By that way you can see power amps harmonics of 10k signal, taken from the Cosmos DAC+LPF10k at level -135db, that's not too bad huh? Some thech guys asking me to make Cosmos ADC/DAC/APU in a single housing to make it synced etc but I think, I have much less risk to produce 1KU Cosmos ADC for 120-130 dollars and 1KU APU separately.

 

[boXem]

boXem | audio, you are right, APU is an extension for really high-precision measurements of DACs. APUs notch has 10Vrms max input level, LNA max level = 10Vrms/100 if +40db gain or /1000 if +60db. So you can measure the noise level of power amps with LNA but for the full-scale power amp output you need some 1/3 resistors divider(I make such things inside of cables) before the notch. However, power amps usually aren't so low-noise and low-distortion devices as modern DACs. BTW, the notch has a 2-positions switchable post gain 0/6db. Cosmos ADC is the plain ADC/USB interface, that's it. We preparing the Cosmos FFT software as well, simple but correctly measuring Cosmos_FFT.exe. The SW will able to control THD compensation coefficients of ES9822 2nd, 3rd, and 5th harmonics, so you can compensate your own Cosmos ADC unit at 10kHz(optimal 1kHz THD compensation isn't matched to 10k) for the minimal distortions, using Cosmos DAC +LPF_10k as a reference sine tone. By that way you can see power amps harmonics of 10k signal, taken from the Cosmos DAC+LPF10k at level -135db, that's not too bad huh? Some thech guys asking me to make Cosmos ADC/DAC/APU in a single housing to make it synced etc but I think, I have much less risk to produce 1KU Cosmos ADC for 120-130 dollars and 1KU APU separately.

Thanks for the details. Indeed, performance is "not too bad" .
Additional question, since ES9842 has the same package and is not a lot more expensive, was there a reason beside price not to use it and paralleling channels to gain a few dB?

 

[IVX]

actually, 9822 has 4ch inside as well, and I have to sum pair of channels to make 1 semi-mono channel or all 4ch to get 1 mono ch. If you'll not set up these hidden channels to use only ch 1 you'll get -6db max level. ESS as is.. To me, 9822 is optimal because of cheaper vs 9842.

 

[boXem]

actually, 9822 has 4ch inside as well, and I have to sum pair of channels to make 1 semi-mono channel or all 4ch to get 1 mono ch. If you'll not set up these hidden channels to use only ch 1 you'll get -6db max level. ESS as is.. To me, 9822 is optimal because of cheaper vs 9842.

I was guessing that the chip was the same but I would have thought that they would "fuse out" extra channels.

 

[IVX]

In ES9822 channels 3 and 4 don't wire-bonded to QFN pins and internally shorted to 1 and 2, if you about that.

 

[AnalogSteph]

Exciting times we are living in. You rock, dude.

 

[pos]

@IVX, any plan for a mic preamp with the same form factor and usb c power?

 

[IVX]

pos, no such plans so far. Cosmos APU has 40/60db low noise preamps, I guess it could be an ideal mic LNA.

 

[pos]

Cosmos APU has 40/60db low noise preamps, I guess it could be an ideal mic LNA.

Is it using a 3.5 jack for balanced input? What is the input impedance?
I guess adding an external phatom power could be the ticket...

 

[Hotmailhero]

@IVX
Can you help me this question for ES9822?
I removed all mic amp circuit, that is XLR jack connects to ES9822 in1_+ and in1_- directly by a series capacitor. ES9822 has internal DC offset for VIN.
I used UPV and AP555 to generate 1Khz, DC offset =2.25V (half of AVDD), and see noise level from 20-20Khz in RMAA tool.
Question:
When 1Khz input level become higher, the noise level also raised from -150dBu to about -120dBu. Did you see this issue ago?
Many thanks!

 

[IVX]

Hotmailhero, Cosmos ADC has -127db(A) an idle noise level@32/48k, hence, unweighted will be 124-124.3db. [email protected] is 0.00003% i.e max harmonic(3rd one) -134db but THD+N -121db. The conclusion is Cosmos ADC has about 3db noise modulation @0dfs/-183dbfs. I just recalculated my DACs modulation of noise, 9038D has -125db(A) noise-floor i.e. -123db unweighted and THD+N -118db(no-load -.5dbfs), so, there is up to 5db of the noise modulation. Cosmos DAC has -130db(A) i.e. -127db unweighted and THD+N -124.5db, so, the noise modulation is about 2.5db. 9038D is the portable DAC with lots of compromises, and no surprise that the noise modulation is higher than Cosmos ADC and DAC, however, if you'll take a look at the Cirrus cs43131 and similar, you can notice they have a huge amount of the noise modulation -127db unweighted and THD+N -115db. I think well-implemented ESS chips are still on the top of the performance pyramid, even if they are worst documented.

 

[Chrispy]

Just on it's own or in particular implementations?

 

[IVX]

pos, the impedance of the LNA complex due to input LCR filter.

 

[IVX]

Chrispy ??

 

[Chrispy]

Chrispy ??

Got me, why don't you explain it?

 

[IVX]

Chrispy, sorry, I've no idea what you talking about.

 

[Chrispy]

Chrispy, sorry, I've no idea what you talking about.

LOL if you don't I certainly don't. Do you have a clue?

 

[IVX]

LOL if you don't I certainly don't. Do you have a clue?

sorry, I'm too busy to play charades, when you'll ready, pls try to ask again. I have to prepare a lot of things for the production, including giftbox design and so on with no relation to electronic design, all that on me, really no time for games..

 

[Chrispy]

sorry, I'm too busy to play charades, when you'll ready, pls try to ask again. I have to prepare a lot of things for the production, including giftbox design and so on with no relation to electronic design, all that on me, really no time for games..

Whatever, you can play charades or do the idiotic karaoke for all I care....giftbox design sounds pretty trivial tho. Who are you?