E1DA Cosmos ADC

[pjug]

Thinking again about trying the TRRS input. How should the switches be set for 43VRMS (use the max setting of 10V?)

Sorry if this has already been discussed.

 

[IVX]

pjug, yes, you are right 10V setting will make AUX 43V 0dbfs. The 1.7V setting means 35V for the AUX input.

 

[mansr]

I just noticed that the left and right channels are misaligned by one sample. What's with that?

 

[Atanasi]

yes, you are right 10V setting will make AUX 43V 0dbfs. The 1.7V setting means 35V for the AUX input.

What's the formula between these two?

 

[IVX]

I just noticed that the left and right channels are misaligned by one sample. What's with that?

I have to check.

 

[IVX]

What's the formula between these two?

Huh, I did not think about it but it is a linear dependency, and as you can see 43-35 ~10-1.7 is the same 8Vrms difference.

 

[dominikz]

Huh, I did not think about it but it is a linear dependency, and as you can see 43-35 ~10-1.7 is the same 8Vrms difference.

Is the input impedance change dependency linear as well?
I.e. if 10Vrms setting has 3.48kΩ and corresponding Aux 43Vrms input has 13.6kΩ, does that mean that in 1.7Vrms / 640Ω mode the Aux input impedance is 10.76kΩ? Thanks!

 

[IVX]

sure.

 

[pjug]

Do I understand correctly that volume control is how stereo vs mono mode is selected? It is possible to lock the device in stereo mode? Or maybe some people would want to lock in mono. I see there is a firmware tool so I am guessing it is possible but I wanted to ask for guidance before messing with the firmware.

 

[IVX]

Sure, I've described that here https://e1dashz.wixsite.com/index/cosmos-adc
I can make a special FW with fixed STEREO/MONO mode but why don't you reduce the volume of ADC instead?

 

[pjug]

Sure, I've described that here https://e1dashz.wixsite.com/index/cosmos-adc
I can make a special FW with fixed STEREO/MONO mode but why don't you reduce the volume of ADC instead?

So far I have only made sure the TRRS is working with line level signals but I want to record power amplifier output in stereo using the 43Vrms range. This ADC is good in enough in stereo for anything I will be doing, so I'd rather just make sure it is always in stereo. I don't think you need to make special firmware if I can change it with your FW tool. But I wanted to ask first since you have a warning in red about using the firmware tool!

 

[staticV3]

@pjug please install this driver and make sure that your Cosmos is using it in the Device Manager (it'll say Microsoft with the generic one):


With that done, you can go into the Sound Control Panel, set the Volume (= recording mode) for the Cosmos once, and the next time you plug in your Cosmos, the volume will be restored:

 

[pjug]

@pjug please install this driver and make sure that your Cosmos is using it in the Device Manager (it'll say Microsoft with the generic one):
View attachment 207947

With that done, you can go into the Sound Control Panel, set the Volume (= recording mode) for the Cosmos once, and the next time you plug in your Cosmos, the volume will be restored:

Thanks to you and to Ivan. I get it now.

 

[staticV3]

Here's a wiring layout for Cosmos APU -> ADC:

 

[1231rq32r1qw32r]

Oh, and one more interesting, if not say unprecedented, DSP feature for vinyl rippers is distortions compensation!
Yes, in the same way that you calibrate the Cosmos ADC you can reduce the distortions of your LP as well.

Could you give me some more (basic) info on this? I'm very interested as I already use a COSMO ADC for vinyl ripping and I am looking at getting two APUs for a better RIAA/Preamp stage. I'm looking to replace my ageing Cambridge Audio 640P phono stage

I don't understand how this distortion compistation would be achieved and what specific distortions we'd be removing

Thank you!

 

[IVX]

1231rq32r1qw32r, Cosmos ADC has the control app for the Windows - Tweak_Cosmos.exe you can adjust there 2nd and 3rd harmonics levels to compensate for nonlinearities of any input sources. You'll not able to reduce 1% of LP distortions to .1% but rather down to .5%. BTW, the same thing you can try with speakers, 9038D/S DACs have a similar Tweak_9038 app for Android, where you can try to compensate for your particular speaker system's nonlinearities. IMO, that scenario is even more interesting due to different LPs may have a different distortions profile and if you do compensate one LP with the test-sine record, it is no guarantee that LZ II disk will get less THD as well.

 

[pma]

New user here . The ADC has arrived an hour ago. I use WIN 8.1 and there was no installation issue, as I had the Comtrue SXW driver pre-installed.

Below the 1st measurement with E1DA Cosmos ADC (my small class AB amp). Looking forward to measure my class A, which I have not been able to measure properly yet.

 

[IVX]

I did test 7pcs APU and gave Sunny to sell on our Aliexpress. All have H2 and H3 <-150db @5Vrms 1Khz.

 

[Rja4000]

I did test 7pcs APU and gave Sunny to sell on our Aliexpress. All have H2 and H3 <-150db @5Vrms 1Khz.

How do you check such a low level ?

 

[IVX]

Rja4000, it is a long story, if you didn't hear about my future project Cosmos DAC pls read here https://www.diyaudio.com/community/threads/low-distortion-audio-range-oscillator.205304/page-490