Best spec ADC Chip currently.... ??

[IVX]

tjstyle, of course, no, who may need that if fully differential is there?

 

[tjstyle]

tjstyle, of course, no, who may need that if fully differential is there?
View attachment 144585

Who may need? When the D.U.T only have S.E output. Like the E1DA 9038D for example.

 

[IVX]

tjstyle, if we are not stupid people, we'll use only balanced inputs whatever DUT is.

 

[tjstyle]

tjstyle, if we are not stupid people, we'll use only balanced inputs whatever DUT is.

Ha..ha.. yep, still.. there is stupid people (like me) will ask you a same question.

Waiting, Cosmos come up in Aliexpress..

 

[IVX]

tjstyle, if you have choice between balanced and unbalanced inputs, always better to go with the balanced, whatever DUT SE or not. Does not exist any reason to use unbalanced instead because balanced is better for all respects but the economy.

 

[tjstyle]

tjstyle, if you have choice between balanced and unbalanced inputs, always better to go with the balanced, whatever DUT SE or not. Does not exist any reason to use unbalanced instead because balanced is better for all respects but the economy.

Of course, agree..

I also need adding extra cost to convert balanced signal from DAC to SE output in my new toys.

 

[Earfonia]

The 3rd device in the Cosmos line is Cosmos DAC, dual ES9038Q2M based, in the same case as ADC and APU. DR 130db(A) THD+N@1kHz <-124db or .6PPM 0.00006%. 2 XLRs and 3.5mm jack(HPA) outputs. Each XLR could be switched to be normal DAC balanced output or DAC+LPF 1/10kHz balanced output 10Vrms to use such harmonics-filtered output as an ultra-pure generator for power amps measurements. DAC+LPF output to Cosmos APU next to Cosmos ADC shows -128db THD+N@1kHz. Price is truly TBD but within $150-170 limits in my mind.
PS: the notch had -20db reduction ratio, so the reading -104db needs to be corrected to -20db, hence, THD+N <-124db, the same about 0.0006% reading needs to be divided by factor 10.

In ASIO mode in Windows, with most windows app like DAWs (Digital Audio Workstation) or REW we only can select one device at a time. If Cosmos ADC and Cosmos DAC are 2 different devices connected to two USB ports, how do we use them together? Let's say how to use them with REW in ASIO mode? I prefer to pay more but to have both ADC and DAC in one single device and using only one USB port. It is a lot easier that way to use it in ASIO mode with Windows applications. To keep the size small, the DAC output port can be let say 3.5mm, 2.5mm, or 2x 1/4" TRS balanced output.

 

[KSTR]

In ASIO mode in Windows, with most windows app like DAWs (Digital Audio Workstation) or REW we only can select one device at a time. If Cosmos ADC and Cosmos DAC are 2 different devices connected to two USB ports, how do we use them together?

Good point. I think there is no simple solution to that general problem. USB Audio devices, at least all reasonable modern ones, are their own clock masters so it normally (for standard audio application) doesn't make too much sense to use more than one at a time as sample rates will inevitably drift apart (unless the device clocks can be sync'ed with other means, like a master-slave clock distribution via AES3 or SPDIF/TOSLINK). For measurements, this is a limitation as well, but not a severe one.

ASIO has the further limitation that even when the driver and hardware is capable of multi-device operation like some RME products you still can use only one sample rate at a time for all devices. The ADI2-Pro as clock slave can sync on the incoming clock, even with a multiplier applied... which is the point here. The only way to make use of this is seperate computers. I often use an old laptop with REW etc running under Linux and have a remote display connection for convenience. A second OS in a Virtual Machine on the same host might work if USB access is properly proxied and resources are ample... havn't tried this as of yet.

 

[phofman]

Win10 as vmware player guest on linux host, usb port proxied from host linux to the win10, and I am getting random underruns on win10 -> usb gadget running on a different rpi4 device. Native win10 -> rpi4 OK. I am afraid proxying USB port to the virtual guest adds some timing overhead which may cause problems in isochronous streams.

 

[boXem]

Several instances of REW can be run in parallel. Isn't it possible that each of them run with a different ASIO driver?

 

[Grooved]

Several instances of REW can be run in parallel. Isn't it possible that each of them run with a different ASIO driver?

Just tried and opened two instances of REW, and it appears that each one can use a different ASIO driver but only want to use it if you select both input and output on the same device. I can generate something to output on device 1, and see it enter on the input of device 2, but I don't see how to measure on the instance 2 as it looks like it want the output signal from this device 2, and not from another one.
Don't know if I explained it correctly, but I don't know how to do it at this moment. Don't have more time available, so I will test it later.

 

[boXem]

Just tried and opened two instances of REW, and it appears that each one can use a different ASIO driver but only want to use it if you select both input and output on the same device. I can generate something to output on device 1, and see it enter on the input of device 2, but I don't see how to measure on the instance 2 as it looks like it want the output signal from this device 2, and not from another one.
Don't know if I explained it correctly, but I don't know how to do it at this moment. Don't have more time available, so I will test it later.

I gave a quick try to the multiple instances and had REW crashing...
Then I realized that ASIO4All allows to handle several devices at once. You can choose which one is the input and the output.
Also gave it a try, output on Motu, input on PC sound-card, output was not reaching the Motu HW, but I suspect that the Motu ASIO drivers were conflicting with ASIO4All. Since I was too lazy/busy to uninstall the Motu drivers I didn't go further.

 

[Grooved]

I gave a quick try to the multiple instances and had REW crashing...
Then I realized that ASIO4All allows to handle several devices at once. You can choose which one is the input and the output.
Also gave it a try, output on Motu, input on PC sound-card, output was not reaching the Motu HW, but I suspect that the Motu ASIO drivers were conflicting with ASIO4All. Since I was too lazy/busy to uninstall the Motu drivers I didn't go further.

Right, I can't test now but I also thought about using ASIO4ALL to see if it can work. It sometimes works perfectly in one configuration, and sometimes don't, depending on the the devices and softwares used. That said, ASIO4ALL will be seen by REW as the ASIO device, but I'm not sure in this case if ASIO4ALL uses the ASIO from your MOTU or its WDM driver, I would say the later

 

[IVX]

The paid version of REW is supporting multidevice or probably I mixed it up and it supports multi channels.. Anyway, you can use another generator app, and actually, I do not see a big deal with ASIO at all. How ASIO can help me to measure THD+N, of freq.response etc?

 

[Grooved]

The paid version of REW is supporting multidevice or probably I mixed it up and it supports multi channels.. Anyway, you can use another generator app, and actually, I do not see a big deal with ASIO at all. How ASIO can help me to measure THD+N, of freq.response etc?

I'm not sure using ASIO can change something by itself in your case, it would be more for people that want to use two device and have at least one with some restriction on WDM/WASAPI compared to ASIO, which happens (don't remember which one but I have one device working in 24bit with ASIO, but limited to 16bit with WDM/WASAPI)

 

[IVX]

BTW, some Russian E.Sokol from Ural region made some handy WASAPI gen with the bouquet of anti-harmonics arrangement to compensate almost any DACs harmonics down to -150db(actually, down to level that you able to proof. Such a proofing is the not a trivial task at all, maybe I'll tell you once about how I did proof < = -150db of my Cosmos DAC +LPF harmonics level).

 

[boXem]

The paid version of REW is supporting multidevice or probably I mixed it up and it supports multi channels.. Anyway, you can use another generator app, and actually, I do not see a big deal with ASIO at all. How ASIO can help me to measure THD+N, of freq.response etc?

REW pro allows multi input capture. Not related.
@Grooved wonders how to use your Cosmos DAC and your Cosmos ADC with REW. I do not see how using a separate generator would allow THD+N(P) or THD+N(F) automatic measurements in example.

 

[Grooved]

REW pro allows multi input capture. Not related.
@Grooved wonders how to use your Cosmos DAC and your Cosmos ADC with REW. I do not see how using a separate generator would allow THD+N(P) or THD+N(F) automatic measurements in example.

No no, I was not wondering anything about @IVX DAC or ADC
I was just answering on what I saw in REW (non-Pro version but multi-instance version) with ASIO on two different devices at the same time, regarding any device, not specifically @IVX 's devices

@IVX , is this "Harmonic Sine Generator Pro" a custom software made for you, or is it available to everybody, I didn't found anything on the web

 

[boXem]

No no, I was not wondering anything about @IVX DAC or ADC
I was just answering on what I saw in REW (non-Pro version but multi-instance version) with ASIO on two different devices at the same time, regarding any device, not specifically @IVX 's devices

@IVX , is this "Harmonic Sine Generator Pro" a custom software made for you, or is it available to everybody, I didn't found anything on the web

Was not you, was @Earfonia , sorry, but the problem remains the same .

 

[phofman]

REW using java does not support WASAPI out of the box, without any ASIO-WASAPI bridge. I tested FlexAsio with WASAPI USB UAC2 Win10 driver in exclusive mode and was getting dropouts at high speeds (384kHz, 768kHz). I am looking at options of a simple wasapi java driver for REW to use, based on Henrik's practical experience with his new native wasapi support in CamillaDSP, it will take some time to sort out.