IVX
Major Contributor
well, I'm not sure regarding Audiophonics but Sunny has it as APU cables(3.5mm to XLR male or 3.5mm to XLR female, also you can get "ADC probe" cables aka XLR male to 2 hooks In+/In- and one crocodile-clamp to GND).
-
WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
E1DA Cosmos ADC
- Thread starter mansr
- Start date
IVX
Major Contributor
sorry, I don't understand your question..
IVX
Major Contributor
IVX
Major Contributor
yes, if any questions, Sunny is online all day.
I was waiting for the Cosmos Scaler because of the low input impedance of the Cosmos ADC, and while the Cosmos APU solves this issue for 1kHz signal, I wanted to measure IMD, Multitone, etc. I finally got the Scaler and did a quick test. Let me share the results.
https://www.audiosciencereview.com/...ts-and-measurements.37739/page-3#post-1328586
I measured two DACs with Cosmos Scaler and ADC (Grade B). One is TOPPING D30Pro (Balanced) which did not have any problem with the input impedance of Cosmos ADC. The other is an ES9023 based DAC board (SE), which had high level distortion at low input impedance. Below is a comparison of without Scaler, with Scaler 0dB, Scaler Auto and APU 1kHz notch (THD+N and 1kHz signal dBFS at 4.5V input range). The input range of Cosmos ADC was all 4.5Vrms, measured by Stereo mode of ADC (not MONO).
As you see, Cosmos Scaler reduced harmonics of the ES9023 DAC drastically. Without Scaler (Red) vs with Scaler 0dB (Green).
I was able to measure IMD (SMPTE 60Hz and 7kHz) either by 0dB or Auto settings of Cosmos Scaler.
While the Auto setting of Cosmos Scaler was unstable when measuring multitone. 0 dB (or fixed gain) worked fine.
I am satisfied with these results. Thank you @IVX for this nice variable gain input buffer.
https://www.audiosciencereview.com/...ts-and-measurements.37739/page-3#post-1328586
I measured two DACs with Cosmos Scaler and ADC (Grade B). One is TOPPING D30Pro (Balanced) which did not have any problem with the input impedance of Cosmos ADC. The other is an ES9023 based DAC board (SE), which had high level distortion at low input impedance. Below is a comparison of without Scaler, with Scaler 0dB, Scaler Auto and APU 1kHz notch (THD+N and 1kHz signal dBFS at 4.5V input range). The input range of Cosmos ADC was all 4.5Vrms, measured by Stereo mode of ADC (not MONO).
As you see, Cosmos Scaler reduced harmonics of the ES9023 DAC drastically. Without Scaler (Red) vs with Scaler 0dB (Green).
I was able to measure IMD (SMPTE 60Hz and 7kHz) either by 0dB or Auto settings of Cosmos Scaler.
While the Auto setting of Cosmos Scaler was unstable when measuring multitone. 0 dB (or fixed gain) worked fine.
I am satisfied with these results. Thank you @IVX for this nice variable gain input buffer.
Last edited:
Has anyone tried the Hifime High-Speed USB Isolator v2 with the non-isolated Cosmos ADC? It's reportedly using the same AD UM4166 as the Topping HS02 isolator, but only supplies up to 500 mA of current. (And it's cheaper.)
IVX
Major Contributor
I bought their previous HS ISO $100, and that was absolutely useless due to 5000pF(Cosmos ADCiso 8pF i.e. 625x times better) of the barrier capacitance.
I think you can use a battery-powered laptop to break the GND loop.
I think a big part of it has to do with the DC-DC converters used to provide power across the barrier. Using a separate DC supply, like what's done on the ADCiso, is a way better idea. But, people want convenience and low price more than they want performance, so that's what we get.
IVX
Major Contributor
IVX
Major Contributor
A battery-powered laptop is good enough too.
As user MC_RME writes in the post I linked to, he measured the capacitance of the new, v2, high-speed, €57 version to 71 pF. So only 10x worse than ADCiso.
(Do you have a rough idea of the amount of capacitance a laptop running on battery presents to the audio source?)None of my laptops have working batteries anymore unfortunately. Also I prefer to use my workspace full-size computer in general.
I would also rather have a separate isolator that I could use for other purposes + non-isolated Cosmos for the same price as a Cosmos ADCiso. The Cosmos will be used very rarely for measurements only.
IVX
Major Contributor
70pF is good enough as well, practically no difference vs 8pF. A laptop I guess may have about 40pF(C = 4*pi*e_0*R doubled to include cables) of selfcapacitance but it depends on where. In fact, we have a deal with distributed capacitive dividers, in the case of your USB ISO unit 70pF is between the ADC and the source of the noise. In the case of a laptop 40pF of self capacitance to the space or to the Earth but not directly to the source of disturbances. I hope it is clear, sorry if my eng is poor.
Well, I've ordered a Cosmos ADC Grade B + the Hifime isolator now, so in a week or so we'll know if it works or not! Cost (including shipping for the isolator and 25 % VAT): €305, compared to €343 for the Cosmos ADCiso (Grade A?) only. (From Audiophonics.)
Has anybody tried the cosmos ADC with the APX flex software? Looks like it should work...
www.ap.com
APx500 Flex Audio Analyzer
No thanks.Has anybody tried the cosmos ADC with the APX flex software? Looks like it should work...
APx500 Flex Audio Analyzer
...I'd rather buy an used AP.
Similar threads
