E1DA Cosmos ADCiso Review

[amirm]

Why didn’t you make a THD vs frequency measurement? It's very important imho

Oops. I had measured it but forgot to put it in the review. it is there now:

The dashed lines are with 4.5 volt range.

 

[amirm]

It seems Cosmos ADC Grade B at 0dbfs i.e. 4.5-4.6Vrms will give equal to APx555 THD+N -121db, 4V input has lack -1.5db. AP isn't critical to such a difference due to autoranger onboard, but Cosmos ADC is straight ADC and nothing more. That's why it is correct to measure THD+N at -0.5..0dbfs level. BTW, L7 did measure Cosmos ADC 2 years ago and got -121.2db of sinad at 4.5Vrms.

I went up to 4.2 volts and it made no difference. Anything higher and it would no longer be "nominal 4 volts" and would make the comparison to other products unfair.

 

[amirm]

Judging by the last sentence, if I understand this correctly, this is the analyzer's DR including the auto scaler?
How much gain does AP's scaler apply?

Yes to first question. Unknown for the second. AP does have a way to disable the auto-scalar but that is to speed up measurements, not to bypass it.

 

[amirm]

There is the Cosmos Scaler to extend the capabilities of the ADC with this exact feature (and 200K Zin), which I've measured to come in at a dynamic range of ~140dB (from an extremely low level signal with the Scaler's maximum gain of 26dB to 0dB gain 4Vrms @-0,7dBFS).
For those who haven't seen it, the ADC can be set to mono, which lowers THD+N by about 3dB (but also halves its input impedance!).
For super precise measurements, there is also the Cosmos APU with a 1KHz notch and a low-noise preamp, so comparing the ADC by itself to the AP analyzer with its scaler enabled is a bit of an apples to oranges comparison imo, since the Cosmos ecosystem has more to offer than just the ADC

The device badly needs a full tutorial both in text and video. It attracts people who aren't experts in measurements and electronics yet it is more complicated/complex to use than Audio Precision. Such tutorial needs to cover all the corner cases and issues involved in it.

Above is (one of the) reasons I hesitated to test this device. And eventually decided to just test it by itself as to avoid all the complications that go with stringing other things with it.

 

[KSTR]

Well, basic specs and info is here: https://e1dashz.wixsite.com/index/cosmos-adc
But I would agree it's neither complete or well-structured nor fully up to date, it seems.

However, I personally don't see the need for basic tutorial, especially not videos. People who are interested in measurements but have no background should care for themselves to establish that background and learn, it's not the task of a manufacturer, especially when it is a small scale affair like E1DA. Just because this device (and others from that series) is very affordable does not put higher responsibility on the maker, quite the contrary. This is the whole idea of this new maker scene I consider E1DA being a part of. The hardware is cheap and good but you have to show effort and activity yourself and in the community rather than expecting to be spoon-fed. If you want full support and excellent documentation, buy a used AP or a DScope.

 

[Blimple]

Oops. I had measured it but forgot to put it in the review.

Thank you very much for review and measurements!

 

[capslock]

I will be using RME ADI-2 Pro for this, it can sync on SPDIF input for USB connection, even at mutiples of the sample rate. From there I can connect a DUT on SPDIF out and have the whole shebang in sync.
As I have two ADI-2 Pros, I have all options to run the DUT at, say, 48Khz and the Cosmos ADC at 192kHz, still in full sync...
For higher sample rates on the Cosmos, while it does run the SPDIF pin correctly at these rates, it remains to be seen if the physical interface and the partner device can handle it. The other, much more complicated option would be to create a divided down (2x/4x/8x/16x) version from I2S (not using the SPDIF Firmware option) and use that to feed an I2S-->SPDIF converter (WM8804).

Do the two ADI-2 Pros sync to each other? Why two anyway? One would synch on the SPDIF on its input, and its SPDIF output could drive the DUT, couldn't it?

 

[amirm]

People who are interested in measurements but have no background should care for themselves to establish that background and learn, it's not the task of a manufacturer, especially when it is a small scale affair like E1DA

Of course it is. With all my experience I still did not realize the bit about volume control/mono. As I said, there is absolutely nothing in the box as far as documentation. There are a lot of people who are interested in doing measurements and while this is an enabling product, the lack of complete guide will be a deterrent.

A video is very useful as well as it can quickly cover things in words and demonstrations that you can't do in text without writing a book.

 

[pma]

It is absolutely clearly described in the product page

Cosmos ADC | index

e1dashz.wixsite.com

and there are threads here at ASR that verify that users understand how to use it in the mono mode. I agree, this ADC is not for the noobs, however, at $180 one gets better parameters than with this

Audio Precision APx516B Review

This is a review and detailed measurements of the Audio Precision's APx516 audio analyzer. It is on loan from the company and costs from US $6,000. As tested, the cost is around $9,000. The APx516B is featherweight compared to the much, much heavier APx555 analyzer I currently have. You can...

www.audiosciencereview.com

especially if you are technically skilled and understand what you are doing and you are able to build some extending accessories.

 

[Grooved]

Find attached the latest versions, for standard ADC and for ADCiso.

Install instruction here: https://www.audiosciencereview.com/...ds/e1da-cosmos-adc.27038/page-75#post-1959444

Thanks, it appears that I didn't follow the discussion these last weeks and didn't see the latest messages.
I already did some firmware updates for the Cosmos ADC, so this part is OK, what I'm just don't understand is why your attached piece is not the same firmware than the one that Ivan uploaded in his message?
Yours is "Cosmos_ADC_ADCiso_SPDIF_Firmware"
Ivan's firmware is "CosmosADCiso_V13_768_phase_D_SPDIF_nonISO"

I will be using RME ADI-2 Pro for this, it can sync on SPDIF input for USB connection, even at mutiples of the sample rate. From there I can connect a DUT on SPDIF out and have the whole shebang in sync.
As I have two ADI-2 Pros, I have all options to run the DUT at, say, 48Khz and the Cosmos ADC at 192kHz, still in full sync...
For higher sample rates on the Cosmos, while it does run the SPDIF pin correctly at these rates, it remains to be seen if the physical interface and the partner device can handle it. The other, much more complicated option would be to create a divided down (2x/4x/8x/16x) version from I2S (not using the SPDIF Firmware option) and use that to feed an I2S-->SPDIF converter (WM8804).

The second option is what I tried the last time, using the three I2S pins (+GND) and adding MCLK from the chipset extra output, and using a board with Toslink/Coax/AES outputs.
The problem is that I got it working, but always with a little bit of distortion added. I tried several things, and I always got it, so I stopped trying.
So I would prefer to try an SPDIF output directly from chipset and adding a line driver, than trying again to recreate the SPDIF signal from the I2S pins

I will stop to post in this review thread and continue on the Cosmos ADC thread

 

[amirm]

It is absolutely clearly described in the product page

From that page: "I saw on reddit.com complained about LED flashing. Anyone has "am I boomer?" psychological complex, who feels the LED blinking is too much 1960th style, please request in our discord channel for the Boomer_free Firmware"

It is this kind of attitude that has stopped me from testing products from him.

But no, that is not the tutorial I was talking about. Such a tutorial walks through a complete system solution on testing different product categories including the software.

And this kind of hyperbole not matched by my measurements:

 

[peniku8]

The device badly needs a full tutorial both in text and video. It attracts people who aren't experts in measurements and electronics yet it is more complicated/complex to use than Audio Precision. Such tutorial needs to cover all the corner cases and issues involved in it.

Above is (one of the) reasons I hesitated to test this device. And eventually decided to just test it by itself as to avoid all the complications that go with stringing other things with it.

Agreed, the issue for Ivan is language barrier. You see that when you read through https://e1dashz.wixsite.com/index
I'm member of the E1DA Discord server and I see people join there all the time who just bought the ADC without knowing what it even is, which is baffling to me, since (at least to me) it's quite a niche piece of equipment and one would have to have a specific use-case to get it.
AP solves issues by integrating everything seemlessly and automating as much as possible in the software side, but if you want to use a notch+preamp+scaler+ADC that are in separate devices you first need to really understand what each devices does, what you might need it for and how to get 'standardized' measurements with it... I think the scope of such a tutorial/documentation would be very large.

 

[Watire]

When plugged on a Linux system, the E1DA Cosmos ADC shows 2 sliders in ALSAMIXER.
There is "Line" and "Line 1". Windows does not shows 2 sliders.
I have never met a documentation explaining what the second slider does.
This device needs a manual. And even better than that, I think it would benefit from a cheat sheet with a graphic matrix showing the volume actions and a LED colors coding grid. Probably the firmware updating instructions also.
Cosmos is great.
E1DA gears are so cute and competent you just want to collect them all !

 

[amirm]

I think the scope of such a tutorial/documentation would be very large.

It would be but one could start with first steps. For example, how to measure SINAD and FFT per my dashboard for a DAC. Or headphone amp.

The ideal solution would be a fresh new app to create the needed measurements. Having to learn to use REW, Arta, etc. creates its own barrier. And at the end, you still can't quite generate what I product in the reviews (which many like to do).

 

[KSTR]

Do the two ADI-2 Pros sync to each other? Why two anyway? One would synch on the SPDIF on its input, and its SPDIF output could drive the DUT, couldn't it?

Brain fart from my side, sorry. The ADI-2 Pro can scale up and scale down as well (the latter is what we need here), so one unit does suffice:
CosmosADC @192kHz USB read in, and SPDIF ==> RME SPDIF In as Clock source, but set to 48kHz actual sample rate for SPDIF out --> DUT DAC (fed from USB of RME).

 

[Sokel]

Agreed, the issue for Ivan is language barrier. You see that when you read through https://e1dashz.wixsite.com/index
I'm member of the E1DA Discord server and I see people join there all the time who just bought the ADC without knowing what it even is, which is baffling to me, since (at least to me) it's quite a niche piece of equipment and one would have to have a specific use-case to get it.
AP solves issues by integrating everything seemlessly and automating as much as possible in the software side, but if you want to use a notch+preamp+scaler+ADC that are in separate devices you first need to really understand what each devices does, what you might need it for and how to get 'standardized' measurements with it... I think the scope of such a tutorial/documentation would be very large.

I really,REALLY appreciate Cosmos and this product is made.
But marketing 101 is first to create the need and then the product.
And there's no need for something that people don't know where to use and how.

Yes,it's destined to experienced users about measurements but the specific-to-product settings.hidden or unique features in general has to be pointed.
I think it takes a lot longer for Ivan to answer all kinds of questions than writing a PDF NOT about how to measure,etc,but about the device's own use,limitations and specific settings.

 

[peniku8]

And at the end, you still can't quite generate what I product in the reviews (which many like to do).

What do you have in mind? I've been pestering John to integrate functions into REW and about half of what I ask for he implements quite quickly, the other half would require lots of work (automated CEA-2010 measurements, automated amplifier power measurements that output power vs time graphs), but on the "measuring DACs" side I'm not missing anything really.
If you look at my review/measurement threads I usually show the same graphs you show too, except for measuring reconstruction filters, simply because I'm too lazy to break out of REW and feed the DAC from another software so I can run the ADC at a higher sample rate lol

 

[restorer-john]

And this kind of hyperbole not matched by my measurements:

It's misrepresentation, plain and simple.

 

[Sokel]

It would be but one could start with first steps. For example, how to measure SINAD and FFT per my dashboard for a DAC. Or headphone amp.

The ideal solution would be a fresh new app to create the needed measurements. Having to learn to use REW, Arta, etc. creates its own barrier. And at the end, you still can't quite generate what I product in the reviews (which many like to do).

We have Multitone Analyzer for that,fully automated for lots of them!

Beta Test: Multitone Loopback Analyzer software

This is a software beta-test for IMD and THD aficionados with an intense desire for multi-tone audio testing :) The start of the documentation and the download website is here: https://distortaudio.org/multitone.html (for 64-bit Windows) Multi-tone Analyzer (MA) was more of an experiment than...

www.audiosciencereview.com

(plus it generates and measures DSD which no one else does)

Edit:An automated example:

RME ADI-2/4 Pro SE - Auto-measured with Multitone

I don't know if this post is about the extremely nice, new RME ADI 2/4 Pro SE interface or about the new automated measurement capability of the Multitone app :) Most of these measurements were done automatically using a Multitone test plan (I'll share in a separate post). This new feature...

www.audiosciencereview.com

 

[zhgutov]

I still did not realize the bit about volume control/mono

You set the volume below 50% here. In this case the device is working in stereo mode.

It is working in mono mode if you set it above 50%.

If you set the volume to 40-60%, the RIAA EQ will be used (DSP, newer units).

There is some kind of description here:
https://e1dashz.wixsite.com/index/cosmos-adc