E1DA Cosmos ADC

[Grooved]

Grooved, Fig4 page 20

Thanks, just found it in the document.
The rest of the Fig4 is OK for me, I see how SCLK and LRCK are generated, sent on GPIO 1 and 2 then to your I2S ports (if I'm not wrong, and with GPIO3 sending Data), but this top left part, as I understand it, it's only the XIN signal that can be sent on XOUT. Am I right ?
If so, XOUT pin would only work for 48/96/... SR

So I may need two wires to get both clocks, then a switch to select one of both.
I took a moment to place it under a laser scope, and not sure if it would be better to solder wires on the path or directly on the pin.
You think it's better on the path ?

 

[IVX]

Grooved, ooh, an excellent soldering quality, huh? I did point where I would take the MLCK, right?
Especial for you I prepared the new FW with MCLK output at pin#36. It operates at ALL Fs whatever 44.1 or 48 related.

https://drive.google.com/file/d/1FPOeXYfytY3KwIW_M137Gt9Us0ndR1lt/view?usp=sharing

 

[Grooved]

...I prepared the new FW with MCLK output at pin#36. It operates at ALL Fs whatever 44.1 or 48 related...

So much thanks @IVX , it will be easier to place the wire with pin #36, and if it works with all frequencies, it's even better !

 

[Hee]

I measured it with a pkane multitone analyzer.

Isn't it coming out so good?

 

[IVX]

I measured it with a pkane multitone analizer.
View attachment 167983Isn't it coming out so good?

not sure if I understand the question.. The only bad sign I see here is the "SNR 131.5db" it is unrealistic for 100.0%, no one of over 200 Cosmos ADC sold had SNR 130db. The best one is on my desk with 129.7db(A). So I do not recommend you trust too much that software yet.
PS: strange but I didn't find by google the "pkane multitone analizer"..

 

[Hee]

not sure if I understand the question.. The only bad sign I see here is the "SNR 131.5db" it is unrealistic for 100.0%, no one of over 200 Cosmos ADC sold had SNR 130db. The best one is on my desk with 129.7db(A). So I do not recommend you trust too much that software yet.
PS: strange but I didn't find by google the "pkane multitone analizer"..

Hi, Ivan.

Beta Test: Multitone Loopback Analyzer software

This is a software beta-test for IMD and THD aficionados with an intense desire for multi-tone audio testing :) The start of the documentation and the download website is here: https://distortaudio.org/multitone.html (for 64-bit Windows) Multi-tone Analyzer (MA) was more of an experiment than...

www.audiosciencereview.com

This is the link to Pkane. His program keeps updating, so let's wait.

 

[IVX]

aaah, I see? it is beta so, ok.

 

[Jimbob54]

Am I the only one wincing at the idea of @pkane 's Analizer ?

 

[IVX]

Jimbob54, please tell us why?

 

[Jimbob54]

Jimbob54, please tell us why?

ANAL izer. Childish humour, sorry. Sounds like a nasty medical procedure where one wouldn't want anything.

 

[pkane]

ANAL izer. Childish humour, sorry. Sounds like a nasty medical procedure where one wouldn't want anything.

Use it with your best ANALizer probes for best results.

 

[Hee]

Pkane. I'm sorry.
I spelled it wrong.

I used an automatic translator, which told me so.
It's late, but I modified it.

 

[peniku8]

Just right now I testing the latest version of Cosmos APU proto with 48VDC phantom power as a mic preamp with Rode NT1A. Sounds great to me with minimal noise.

Could you give us a bit more info on this? How much mic gain will be available? I'm looking for a clean ADC which I can use for equipment and also speaker measurements and the upgraded APU would be a great compliment/extension for the Cosmos ADC. Any rough ideas when it might be available and how much it'll cost?

 

[gcompari]

Jimbob54, please tell us why?

May you update the Discord "invite" in your signature? I'd like to send it to a friend, but he told me it is "invalid"...

 

[IVX]

Could you give us a bit more info on this? How much mic gain will be available? I'm looking for a clean ADC which I can use for equipment and also speaker measurements and the upgraded APU would be a great compliment/extension for the Cosmos ADC. Any rough ideas when it might be available and how much it'll cost?

the gain is switchable 34/60db, which is rather a 48V condenser mic suitable. 48VDC phantom power is also onboard. I was sure APU will be released a couple of weeks later than Cosmos ADC but I keep improving that. The last mod was about 48VDC phantom power, now I trying to maximize the notch resolution(<-150db 1kHz, <-135db 10kHz). The difficulty is the suitable sine source is pretty much doesn't exist. AP analyzers don't guarantee such resolution, custom made oscillators, like Victor's one, promises that but I have doubts. Last week I did build one oscillator according to Victor's schematics ut didn't get the promised harmonics resolution mostly due to this being way too noisy. If harmonics are lower than the noise floor, you'll never see the solid result, only floating level. So, I'm busy about searching for a way to prove the actual APU resolution.
The price is expected within $100, there are no really expensive parts only 4 trimmers(and they require iterative adjustment) may noticeably complicate the production.

 

[IVX]

May you update the Discord "invite" in your signature? I'd like to send it to a friend, but he told me it is "invalid"...

done, thank you!

 

[IVX]

BTW, I made the second proto of the Cosmos Scaler preamp, a relatively simple device with the gain knob 0..20db to provide low noise and distortions high impedance input preamp for the Cosmos ADC. Input and output range is up to 10Vrms, 2 channels, USB-C powered, 20kOhm input impedance balanced and 10 unbalanced. This is an instrumental amplifier that uses OPA1612 and 4 relays to get 16 steps of the gain with minimal distortions. The device contains RGB LEDs(the same as Cosmos ADC has) to help you evaluate the output level. Red LED indicates the overdrive condition(10Vrms), green one 4.5Vrms, and blue 1.7Vrms(i.e. lower range of Cosmos ADC). The device is my reaction to complains that Cosmos ADC can not correctly measure a junk-level DACs with nonbuffered 1kOhms output impedance, and also for vinyl-rip enthusiasts to lift up turntable's output level to 3-5Vrms with maximum fidelity. The last reason is I like such knobs and your money

 

[audiofun]

is there APU news as well? When will it be released?

 

[peniku8]

the gain is switchable 34/60db, which is rather a 48V condenser mic suitable. 48VDC phantom power is also onboard. I was sure APU will be released a couple of weeks later than Cosmos ADC but I keep improving that. The last mod was about 48VDC phantom power, now I trying to maximize the notch resolution(<-150db 1kHz, <-135db 10kHz). The difficulty is the suitable sine source is pretty much doesn't exist. AP analyzers don't guarantee such resolution, custom made oscillators, like Victor's one, promises that but I have doubts. Last week I did build one oscillator according to Victor's schematics ut didn't get the promised harmonics resolution mostly due to this being way too noisy. If harmonics are lower than the noise floor, you'll never see the solid result, only floating level. So, I'm busy about searching for a way to prove the actual APU resolution.
The price is expected within $100, there are no really expensive parts only 4 trimmers(and they require iterative adjustment) may noticeably complicate the production.

That sounds great, I will get one once it's released. For now I have a Cosmos ADC on order and will be pairing it with a Topping D10b.
For the clean source.. is it not possible to use a good DAC and send the signal through a passive bandpass filter to remove noise and distortion above and below 1khz? Or notch out the harmonics if you just need better THD. DAC at 1khz through a 2khz and a 3khz notch should yield pretty good results?
For oscillators I'd be worried about frequency drift. If it's not perfectly on the sharp notch frequency, the notch will have much less reduction...

 

[IVX]

I using that idea in Cosmos DAC already to reduce -130-135db of 3rd to -145db(2nd ord LPF on OPA2156) but it is not the limit of APU at all. So, I still need better sine.