E1DA Cosmos ADC teardown

[IVX]

Warrant, oh, this one for sure Ok, whatever, Cosmos ADC set to 4.5V or 10V input sensitivity.

 

[trl]

"Output level: max 15V RMS"

As long as you respect ADC's input voltage and preamp's output voltage you should be fine. I would say that all preamps with an output voltage lower than 10V RMS should work just fine with Cosmos, but perhaps @IVX could jump in with more details about this.

Even 2MP can be setup to 2V RMS on outputs, so you need to choose the proper Cosmos selector for this.

 

[juliangst]

How do you use the dummy load board? Can you just plug the 2.5mm balanced into the ADC and connect the amp you want to measure to the 3.5mm or do you have to use those hook clips?

 

[IVX]

juliangst, just like this

PS: don't forget to switch Off 11 and 12 DIP-Switch, also connect the GND of the power-amp to the ADC GND(XLR pin#1). Please, turn On the amp only after you did connect all to ADC, and read there please as well.

Cosmos ADC | index

e1dashz.wixsite.com

 

[juliangst]

juliangst, just like this

https://static.wixstatic.com/media/88f4a9_528ff15e99534e14987ebffc8e1af640~mv2.jpg/v1/fill/w_1473,h_1162,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/88f4a9_528ff15e99534e14987ebffc8e1af640~mv2.jpg

Cosmos ADC | index

e1dashz.wixsite.com

Thanks! Is it possible to see power/voltage vs distortion in the software to measure power output of a headphone amp?

 

[IVX]

Headphone amps will be not optimal for that AUX input due to way too low voltage <<43Vrms. Such stuff is better to measure with XLRs inputs 1.7-10Vrms.

 

[staticV3]

Thanks! Is it possible to see power/voltage vs distortion in the software to measure power output of a headphone amp?

You can measure power/voltage vs distortion in REW, but only after calibrating the software.
The Cosmos ADC outputs only dBFS values and so you have to tell REW what dBFS correlates to what Vrms.

 

[staticV3]

@juliangst oh and also note that the Cosmos Load board was designed for dongle DACs like the 9038S/D, Meizu HiFi, etc. It can not withstand multiple Watts.

 

[juliangst]

@juliangst oh and also note that the Cosmos Load board was designed for dongle DACs like the 9038S/D, Meizu HiFi, etc. It can not withstand multiple Watts.

Yeah, I already expected that it can’t handle lots of power, but I would only use it for measuring dongles and portable stuff anyway

 

[Tuan Huynh]

Headphone amps will be not optimal for that AUX input due to way too low voltage <<43Vrms. Such stuff is better to measure with XLRs inputs 1.7-10Vrms.

I need your help! I use the Cosmos as an ADC for my external mic preamp through XLR input. The specs said 10V input max in the Cosmos, however my preamp specs are +28dbu output at half gain. Is it save when I did that. According to my very low audio signal after recording, I didn't hear any clipping or anything bad.

 

[IVX]

I need your help! I use the Cosmos as an ADC for my external mic preamp through XLR input. The specs said 10V input max in the Cosmos, however my preamp specs are +28dbu output at half gain. Is it save when I did that. According to my very low audio signal after recording, I didn't hear any clipping or anything bad.

Well, I tried about 20Vrms 1kHz sine for 10S and Cosmos ADC with sensitivity 10V did survive.

 

[Tuan Huynh]

Well, I tried about 20Vrms 1kHz sine for 10S and Cosmos ADC with sensitivity 10V did survive.

Do you have any solution for me to use your ADC with my mic preamp for recording since the max output of the mic preamp can go up to 32Dbu. For example the 2.5mm as an alternative?

 

[IVX]

The AUX input has minimal sensitivity of about 35Vrms(ADC gain setting should be 1.7V), it is fine for your 32dbu=31Vrms.
But you'll need to tie the GND wire of ADC to GND of the preamp.

 

[Tuan Huynh]

The AUX input has minimal sensitivity of about 35Vrms(ADC gain setting should be 1.7V), it is fine for your 32dbu=31Vrms.
But you'll need to tie the GND wire of ADC to GND of the preamp.

Do I have to open the Cosmos to do it sir? My preamp has 1 XLR output . Does that means I connect pin 1 of the XLR cable to somewhere in the cosmos?
Thank you for answering my stupid question!

 

[IVX]

Cosmos ADC XLRs also have pin#1 GND, I even have printed that on the front panel, also there is printed 2.5mm AUX pinout:

 

[Tuan Huynh]

Cosmos ADC XLRs also have pin#1 GND, I even have printed that on the front panel, also there is printed 2.5mm AUX pinout: View attachment 246005

Thank you Ivan!!!

 

[TNT]

I need your help! I use the Cosmos as an ADC for my external mic preamp through XLR input. The specs said 10V input max in the Cosmos, however my preamp specs are +28dbu output at half gain. Is it save when I did that. According to my very low audio signal after recording, I didn't hear any clipping or anything bad.

If possible, lower the preamp gain more - this will probably benefit in lower noise also from the mic amp. Check your gain structure. If the preamp can drive low impedances it will be better to set the dip switches for lower input sensitivity.

I record into Cosmos at it's most sensitive setting (1,4v) with only 10 dB gain in the preamp. It ends up -30 dB low for an organ recording in church. I then use digital gain for proper levels. I use bit shift (200% in Amadeus Pro) so no calculation errors - still 18 bits left ;-)

//

 

[TNT]

Have to correct myself - the lower sensitivity on Cosmos, the higher impedance... so thats good

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[IVX]

I record into Cosmos at it's most sensitive setting (1,4v)

Actually, [email protected]. 0dbfs about 1.8Vrms.

 

[Tuan Huynh]

Have to correct myself - the lower sensitivity on Cosmos, the higher impedance... so thats good

//

Thank you for your experiences. i'll do it in post digital gain.