E1DA Cosmos ADC

[MC_RME]

Filter: Can't think of anyone needing that. I would prefer a simple setting like now, but always for all ADCs at the same time. Could be added by having an entry ADC1-4 in the list box, so both options are there - single (as now) and all.

 

[mansr]

Filter: Can't think of anyone needing that. I would prefer a simple setting like now, but always for all ADCs at the same time. Could be added by having an entry ADC1-4 in the list box, so both options are there - single (as now) and all.

The current interface is awkward since changing the filter setting requires two selections (four clicks in all) per ADC, and you can't even see the current state without clicking around. A quick way to set all four to the same value would indeed be nice too.

@IVX, would you consider publishing the protocol used to configure these things? Can't be that hard to reverse engineer, but I'd rather not go to the trouble.

 

[mansr]

OK, here's a little Python program that displays and/or sets the filter and ADC_INT_SEL parameters. Use at your own risk. Requires PyUSB. Should work on most systems.

 

[pkane]

RME ADI-2Pro FS DAC +19dBu (with THD pre-compensation) --> E1DA Cosmos ADC @192k, 6.7v. I obviously need a better sine generator

 

[lucian]

@IVX kindly sent me a sample of the new Cosmos ADC to try out. Here are my impressions of it so far.

What you needed to do to get one to try out ? I want too

 

[lucian]

OK, here's a little Python program that displays and/or sets the filter and ADC_INT_SEL parameters. Use at your own risk. Requires PyUSB. Should work on most systems.

are those settings within permanent and sustain power cycle?

does this access have influence on the presented usb audio device?

 

[trl]

What you needed to do to get one to try out ? I want too

https://www.aliexpress.com/item/100...m=5261.ProductManageOnline.0.0.20764edfQvz51J, but the price of a Grade B is higher than it used to be the price of Grade A couple of weeks ago, not mentioning VAT, Customs charges and delivery fee.

 

[lucian]

https://www.aliexpress.com/item/100...m=5261.ProductManageOnline.0.0.20764edfQvz51J, but the price of a Grade B is higher than it used to be the price of Grade A couple of weeks ago, not mentioning VAT, Customs charges and delivery fee.

I mean - @mansr got it obviously for free !?

unfortunately with tax and transport it goes up here to 250€. unfortunately this is just too much for a couple of measurements. guess need to end up using a notch filter and a not so perfect adc.

 

[mansr]

are those settings within permanent and sustain power cycle?

does this access have influence on the presented usb audio device?

The settings are permanent. Using the program does not interfere with a running capture.

 

[mansr]

I mean - @mansr got it obviously for free !?

Mine is a pre-production sample.

 

[Grooved]

unfortunately with tax and transport it goes up here to 250€. unfortunately this is just too much for a couple of measurements. guess need to end up using a notch filter and a not so perfect adc.

If you're in the euro zone, Aliexpress price includes tax now (it written bellow the price), it shows 167+9 for shipping so €176 including tax and shipping for the B grade in stock. You should have nothing more to pay than that

 

[lucian]

If you're in the euro zone, Aliexpress price includes tax now (it written bellow the price), it shows 167+9 for shipping so €176 including tax and shipping for the B grade in stock. You should have nothing more to pay than that

oje you killing me. now i think again :\

what is the difference between Bundle1 / Bundle2 / Bundle3 ? Only the calibration? What about the other circuit boards shown in the pictures of the ali store page?

edit: found the corresponding threads. B would be enough i guess.

 

[trl]

I mean - @mansr got it obviously for free !?

unfortunately with tax and transport it goes up here to 250€. unfortunately this is just too much for a couple of measurements. guess need to end up using a notch filter and a not so perfect adc.

Still cheaper than my Motu M4, so still the best option for a measurement ADC.

 

[Rja4000]

RME ADI-2Pro FS DAC +19dBu (with THD pre-compensation) --> E1DA Cosmos ADC @192k, 6.7v. I obviously need a better sine generator

You have it already, if you have the ADI-2 Pro.
Just sum the 2 output channels with an Y XLR cable.
Or, alternatively, use it in phone balanced mode and use one of the phone out channels to feed the ADC.

 

[pkane]

You have it already, if you have the ADI-2 Pro.
Just sum the 2 output channels with an Y XLR cable.
Or, alternatively, use it in phone balanced mode and use one of the phone out channels to feed the ADC.

Ah, but that doesn’t help with THD, it just lowers noise by 3dB relative to signal. Still need a more linear sine generator

 

[MC_RME]

Try it. As you can dial down the volume by 2.5 dB (for the same SNR as before) the DAC chips will show significantly lower THD when driven at that level.

Otherwise I recommend to contact Victor from the diy forum. His unique and not expensive generator boards have -150 dB THD @ 1 kHz...

 

[pkane]

Try it. As you can dial down the volume by 2.5 dB (for the same SNR as before) the DAC chips will show significantly lower THD when driven at that level.

Otherwise I recommend to contact Victor from the diy forum. His unique and not expensive generator boards have -150 dB THD @ 1 kHz...

That’s how I’ve been using it (Cosmos ADC in mono/summed mode with both inputs driven and only left channel measured). I usually hunt to find the sweet spot for DACs at or close to 0dBFS to see if it produces a better THD. ADI-2 Pro FS DAC seems to like to be around -0.5 to -1dBFS. I've been looking at Victor's sine generator for quite a while, so maybe now is the time to get one, now that I have an ADC worthy of it

 

[Rja4000]

unique and not expensive generator boards have -150 dB THD @ 1 kHz

I have one, but that's still the RCA version and noise is quite high

 

[MC_RME]

It's built for THD, not THD+N. Also noise is only high when you lower the output signal level by its own pot.. I use it at +19 dBu balanced with passive attenuators at the output.. The skirt around the 1 kHz is high, that's unavoidable in this kind of filter topology, and makes it impossible to see ADC phase noise near the fundamental. But already at k2 it's low enough to see the -150 dB. So no issue for THD measurements.

 

[MC_RME]

Aaah, found the pic: