E1DA Cosmos ADCiso Review

[IVX]

Oh it was. He is talking about me. Same thing he did when I tested his last product. Both times I gave his product the best recommendation I can give and yet, he spits out this kind of poison. I have a short list of companies that I want to have nothing to do with and he was on it. But I decided to give it a second chance only to see a repeat. Like the other people on that list, common sense is not something that was taught to him. Or respect for where he is.

Amir, I want to let you know I love you, and I think you are a good guy just because you established ASR, it is enough. I'm a tech guy, and perhaps too rough, especially when involved in a discussion kinda 2+2=2.7 level. I apologize and wish you be healthy.

 

[KSTR]

As I have said, E1DA is not for beginners, but it is an excellent value for technically oriented skilful users.

Exactly. The main peer group is the audio DIY community, people how design/build/modifiy stuff and have enough EE knowledge to work with gear like the Cosmos.

At this price point it even makes sense to buy one for the only reason to modify it for one's needs, for example a different input stage, or just examine it find out what going on. ESS would not be ESS if they didn't have weird unexplained stuff their datasheets... in this case, why do they introduce a DC offset on the input pins as per their "reference" schematic in the datasheet?

 

[Sokel]

It's interesting to see the same device (Topping D50 III) measured with the same AP software,one with AP555 and the other with Cosmos.
(Cosmos one was measured with slightly lower voltage)



AP555 by @amirm




E1DA Cosmos by @Rja4000

 

[pma]

It's interesting to see the same device (Topping D50 III) measured with the same AP software,one with AP555 and the other with Cosmos.
(Cosmos one was measured with slightly lower voltage)



AP555 by @amirm

E1DA Cosmos by @Rja4000

Is it the same unit, same Topping D50 III serial number?

 

[IVX]

It's interesting to see the same device (Topping D50 III) measured with the same AP software,one with AP555 and the other with Cosmos.
(Cosmos one was measured with slightly lower voltage)

View attachment 366105

AP555 by @amirm


View attachment 366106

E1DA Cosmos by @Rja4000

such DACs are not calibrated individually, hence, they couldn't be considered as references, i.e. all D50 III will be different. However, Rja4000, I guess, used APU+ADC, and this combo has -135db residual THD+N, unlike AP -125db. Whatever, -125db or -130db a DAC's sinad(ES9039Pro has -130db@1k), APx555 will boringly report -124..-125db.

 

[pma]

Yes, noise to be calculated as a root from sum of individual noise voltage squares.

 

[Sokel]

Is it the same unit, same Topping D50 III serial number?

such DACs are not calibrated individually, hence, they couldn't be considered as references, i.e. all D50 III will be different. However, Rja4000, I guess, used APU+ADC, and this combo has -135db residual THD+N, unlike AP -125db. Whatever, -125db or -130db a DAC's sinad(ES9039Pro has -130db@1k), APx555 will boringly report -124..-125db.

@pma It's not the same unit of course but it's nice to see how close they are trading THD with noise.
@IVX I thought so too,no unit will measure the same,specially in the abyss of such low noise and THD.

 

[Rja4000]

It's interesting to see the same device (Topping D50 III) measured with the same AP software,one with AP555 and the other with Cosmos.
(Cosmos one was measured with slightly lower voltage)

View attachment 366105

AP555 by @amirm


View attachment 366106

E1DA Cosmos by @Rja4000

I measured with the D50 III set for 4V range.
Amir measured with the D50 III set to 5V range, at -1.5dBFS output level.

 

[welwynnick]

Like many round here, I suspect, I got into HiFi deep into the 20th century.

Do you remember that the battle of the egos was about who had the best ears - was it Jimmy Hughes, was it Michael Fremer....?

Now, the battle of the egos is about who has the best audio analyser.

Some things change, some things don't. Shame.

 

[Rja4000]

Is it the same unit, same Topping D50 III serial number?

Obviously not !
I purchased mine directly from Audiophonics (I'm living in Belgium)
Amir is in the US.

 

[Rja4000]

Rja4000, I guess, used APU+ADC

I use APU + RME ADI-2/4 pro SE, for convenience (as an example, it allows me to keep clock perfectly in sync between DAC and ADC).
I could have used your ADC with same results, probably.

 

[pma]

Like many round here, I suspect, I got into HiFi deep into the 20th century.

Do you remember that the battle of the egos was about who had the best ears - was it Jimmy Hughes, was it Michael Fremer....?

Now, the battle of the egos is about who has the best audio analyser.

Some things change, some things don't. Shame.

Sorry, to me, your statement is a nonsense.

 

[Rja4000]

no unit will measure the same

By the way, the AP software measurement is not that stable.
It fluctuates continuously within +/- 0.2dB or so.
I couldn't find a way to average the dashboard value to make it more stable - as I do with Multi Instrument.

 

[IVX]

I use APU + RME ADI-2/4 pro SE, for convenience (as an example, it allows me to keep clock perfectly in sync between DAC and ADC).
I could have used your ADC with same results, probably.

Right, IMO, Cosmos APU is supposed to be a hit but not Cosmos ADC. APU is fine with almost any ADC, even with built-in laptop audio. BTW, AP users may improve their performance dramatically and nearly for free.

 

[pma]

Right, IMO, Cosmos APU is supposed to be a hit

I would still appreciate the input impedance at least 10kohm even at the most sensitive range, or better 100kohm, or 1Mohm at best.

https://www.ti.com/lit/ds/symlink/opa1656.pdf?ts=1714151753008&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FOPA1656

or

https://www.ti.com/lit/ds/symlink/opa2156.pdf?ts=1714213095294&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FOPA2156

 

[KSTR]

I would still appreciate the input impedance at least 10kohm even at the most sensitive range, or better 100kohm, or 1Mohm at best.

To get there, with no noise penalty, requires a very low noise JFET/MOSFET buffer OpAmp in front of the low impedance range divider, per leg... which then requires a high supply voltage (+-15V..+-18V)... which is not available in the ADC. We have to build that on our own.

 

[eeMGee]

To get there, with no noise penalty, requires a very low noise JFET/MOSFET buffer OpAmp in front of the low impedance range divider, per leg... which then requires a high supply voltage (+-15V..+-18V)... which is not available in the ADC. We have to build that on our own.

There is Cosmos Scaler to help:

Cosmos Scaler | index

e1dashz.wixsite.com

EARLY LOOK: The E1DA Cosmos Scaler prototype. As usual, Neil Young (in "World Record" album interview) remains neurotic against digital...

A blog for audiophiles about more objective topics. Measurements of audio gear. Reasonable, realistic, no snakeoil assessment of sound, and equipment.

archimago.blogspot.com

 

[IVX]

To get there, with no noise penalty, requires a very low noise JFET/MOSFET buffer OpAmp in front of the low impedance range divider, per leg... which then requires a high supply voltage (+-15V..+-18V)... which is not available in the ADC. We have to build that on our own.

not really needed just replace 10k 0402 for 100k, that's it.

 

[KSTR]

not really needed just replace 10k 0402 for 100k, that's it.

Ahm, without a conceptual schematic of the input divider and ADC driver, showing basic simplified topology but no details and no component values, it's not clear which resistor you mean here.

 

[capslock]

To get there, with no noise penalty, requires a very low noise JFET/MOSFET buffer OpAmp in front of the low impedance range divider, per leg... which then requires a high supply voltage (+-15V..+-18V)... which is not available in the ADC. We have to build that on our own.

I guess this depends on what you want to measure. If you are measuring say a DAC its output may have a 100 R output impedance but it may not take kindly to being loaded with e.g. 1 k. Putting a buffer with 100 k input impedance in between the DAC and ADC will make the op amp in the DAC a lot happier, and at the same time, the 100 k resistor does not increase noise because it is paralleled by the 100 R output impedance.