E1DA Cosmos ADC

[darmok]

We are keeping our Aliexpress storage for the last 20pcs Cosmos ADC, and preparing for the production new version Cosmos ADCiso(isolated USB version).
BTW, we decided to produce Cosmos Scaler with the same prod.order, so, if anyone is waiting for that "buffer for Cosmos ADC", you are welcome to suggest me anything regarding the Scaler. Currently, there are 2 ch of instrumentation amp, the composite implemented, with variable gain 0..+26db. The gain is manually controllable by 16 log steps or by the autorange mode. The input impedance 200k/100k balanced/unbalanced, output impedance is 20ohm. 0db gain BW 5Hz..8MHz -3db, high-gain BW 5Hz..400kHz(I'd like to reduce to 50-100kHz to get immunity aginst of DAC's noise-shaper noise).

I'm not sure I'm understanding your first sentence correctly - are you saying that there are 20 units available on Aliexpress? If so can you provide a link to the correct vendor to buy from? The ADCiso and Scaler both look interesting, but I already have a USB isolator and the APU on hand which are sufficient for my needs, and I have a project I'd like to get started on using the ADC.

 

[CedarX]

I'm not sure I'm understanding your first sentence correctly - are you saying that there are 20 units available on Aliexpress? If so can you provide a link to the correct vendor to buy from? The ADCiso and Scaler both look interesting, but I already have a USB isolator and the APU on hand which are sufficient for my needs, and I have a project I'd like to get started on using the ADC.

You have to go to Ivan’s E1DA Audio Store at:

https://aliexpress.com/store/1101346048

Right now, there are 4x Grade B, 8x Grade A, and 2x Grade 0 available.

 

[restorer-john]

We are keeping our Aliexpress storage for the last 20pcs Cosmos ADC, and preparing for the production new version Cosmos ADCiso(isolated USB version).
BTW, we decided to produce Cosmos Scaler with the same prod.order, so, if anyone is waiting for that "buffer for Cosmos ADC", you are welcome to suggest me anything regarding the Scaler. Currently, there are 2 ch of instrumentation amp, the composite implemented, with variable gain 0..+26db. The gain is manually controllable by 16 log steps or by the autorange mode. The input impedance 200k/100k balanced/unbalanced, output impedance is 20ohm. 0db gain BW 5Hz..8MHz -3db, high-gain BW 5Hz..400kHz(I'd like to reduce to 50-100kHz to get immunity aginst of DAC's noise-shaper noise).

Why not put two switchable (DIP) switches for LPF and HPF and associated R-Cs to allow for limiting the BW? That way, best of both worlds.

Do you have target prices on the new ISO ADC and the Scaler?

 

[IVX]

The target price is the same as for the original Cosmos ADC, the question is can I do that? I'll try.
The DIP-switch will affect the crosstalk which is already isn't spectacular due to relays.

 

[GXAlan]

How do we tell if the regular E1DA ADC is affected by USB noise? It seems like we already get great results.

Does the isolation work like the Intona (one cable from computer to E1DA) or is it designed to have two cables, one for power and one for data?

 

[IVX]

How do we tell if the regular E1DA ADC is affected by USB noise? It seems like we already get great results.

Does the isolation work like the Intona (one cable from computer to E1DA) or is it designed to have two cables, one for power and one for data?

To get a ground_loop-free result with Cosmos ADC we need to use a battery-powered laptop or USB isolator(just a few USB-ISO on the market are suitable, I guess one of them is Etona), some users found that inconvenient, and asked me to design the ADC with an integrated USB isolator. I did. The measured capacitance between the data USB(may be fixed by a screw to provide a reliable connection) and power USB is 8pF for the assembled unit.
This is the back panel, one of the versions, that probably isn't the final one:

 

[GXAlan]

To get a ground_loop-free result with Cosmos ADC we need to use a battery-powered laptop

Great, so if I am using the battery powered laptop, there is no need for the updated model? Will there be any improvements to the DC? Can that be brought down to -120 dBFS?

 

[lazarian]

Definitely interested in getting one, if I have a Topping HS01 already would that be enough isolation? If not I'll wait out the new version.

 

[IVX]

Definitely interested in getting one, if I have a Topping HS01 already would that be enough isolation? If not I'll wait out the new version.

no, this one works with DACs only, I heard they made a second USB ISO on Ti or AD chip, and that one works with ADCs.

 

[IVX]

Great, so if I am using the battery powered laptop, there is no need for the updated model? Will there be any improvements to the DC? Can that be brought down to -120 dBFS?

All the same as the original Cosmos ADC only isolated and 32/768 is fully supported(no noise rising). Also slightly better 10kHz H3 performance. I see zero reason to improve a DC performance for the clearly AC device. I can add there HPF to bring a residual DC to -150db or so but who needs if that DSP processing is always on(BTW, RIAA mode contains that HPF, but MONO/STEREO no)? I'd like to keep the ADC transparent as possible.

 

[GXAlan]

All the same as the original Cosmos ADC only isolated and 32/768 is fully supported(no noise rising). Also slightly better 10kHz H3 performance. I see zero reason to improve a DC performance for the clearly AC device. I can add there HPF to bring a residual DC to -150db or so but who needs if that DSP processing is always on(BTW, RIAA mode contains that HPF, but MONO/STEREO no)? I'd like to keep the ADC transparent as possible.

It is just nice when trying to measure linearity and looking at graphs.

If RIAA MODE has the HPF, is it simple to set up

<49 stereo, 49 stereo with HPF, 50 RIAA, 51 mono with HPF, >51 mono

 

[pma]

IVX, how to improve the THD 10k performance of the cosmos adc ? Both ASUS STXII and my modded XFi USB HD have better numbers.

I get this from D10s/Cosmos combo. I think it is pretty good.

 

[manisandher]

We are keeping our Aliexpress storage for the last 20pcs Cosmos ADC

I already have a grade B Cosmos, but needed an additional one for another location. Decided to splash out and go for one of the 2 remaining grade 0 units on Aliexpress. I mean, it's still a fraction of the price I've paid for my other ADCs.

Mani.

 

[NDD]

Definitely interested in getting one, if I have a Topping HS01 already would that be enough isolation? If not I'll wait out the new version.

I have the Topping HS01, it works with most DACs but not all, eg doesn't work with my dragonfly red, and does not work with the Cosmos ADC. I bought the Topping HS02 and that works with all DACs I have and works perfectly with the Cosmos ADC.

 

[IVX]

Finally, we decided to order 500pcs Cosmos Scaler production, perhaps, at the same time when we'll order Cosmos ADCiso i.e. during a few weeks.
Cosmos Scaler THD performance test. The input-to-output H3 difference is 1.4db at -161db i.e. Cosmos Scaler(gain=0db) residual H3 is below -175db@1kHz 1.7Vrms and 640ohm of Cosmos ADC input. Hence, at +26db H3 is expected at -150db. At the higher Cosmos ADC range(>1.7V) H3 should be even lower.
For more detail, Archimago test is here: https://archimago.blogspot.com/search?q=Scaler

 

[arvidb]

To get a ground_loop-free result with Cosmos ADC we need to use a battery-powered laptop or USB isolator(just a few USB-ISO on the market are suitable, I guess one of them is Etona), some users found that inconvenient, and asked me to design the ADC with an integrated USB isolator.

I understand why a USB isolator is useful on a single-ended DAC used as a source, as pma describes here. But why an isolator on the Cosmos ADC? It's differential, right? Is its common-mode rejection a lot worse than its measurement capabilities? (I'm new to these kinds of measurements so trying to learn here - also I'm in the market for one of those Cosmos'es so need to figure out if to wait or not.)

 

[pma]

Any source imbalance worsens CMRR, and also HF shield currents are a bad thing if they flow through the PCB.

 

[IVX]

I understand why a USB isolator is useful on a single-ended DAC used as a source, as pma describes here. But why an isolator on the Cosmos ADC? It's differential, right? Is its common-mode rejection a lot worse than its measurement capabilities? (I'm new to these kinds of measurements so trying to learn here - also I'm in the market for one of those Cosmos'es so need to figure out if to wait or not.)

The CMRR is limited by the resistors and especially caps(at high frequencies where typical digital noise is located) tolerance at a lot higher level than THD or noise performance of the ADC. You can use the original Cosmos ADC with a battery-powered laptop to reduce GND loop noise enough but of course, a laptop capacitance is a lot more than Cosmos ADCiso isolation barrier(8pF), hence, Cosmos ADCiso should perform better anyway. On the other hand, Cosmos ADC is for sure cheaper, not dramatically but $20(or about) is money too.

 

[IlyaP]

Hello!
Can anyone upload a couple of their vinyl rip samples from an mc cartridge, made with an APU-ADC?
I have questions about component matching.

1. The output voltage of the mc cartridge is 0.3mV. ADC will amplify by 60dB and we get after the ADC - 300mV. At the ADC Cosmos the minimum sensitivity is 1.7V... Such a ratio of output voltage from the ACU to ADC sensitivity is normal? Wouldn't the recording be quiet and without dynamics?

2. If I use my phono preamp, with an output impedance of 850 ohms and +65dB for mс. Then for the same 0,3mV cartridge I will get 530mV and 850 ohms at the output. I.e. for normal impedance matching I have to choose in ADC Cosmos mode 43V and 13.6kOhm... But nothing will come out of this... How can I use the Cosmos ADC for recording?

 

[morillon]

in mc ... requires an input load adapted to your cartridge and often a gain greater than 60db .. (sometimes we go up to 72db with cartridges at very low output level)
we often see either a sut or an active pre-pre, adapted, put upstream of the riaa "mm"
(seem to me ,if an input impedance setting had been fitted.. could have been a small additional outlet for the scaler)