Given the existing measurements performed already by @Archimago ( http://archimago.blogspot.com/2022/05/early-look-cosmos-apu-high-performance.html) and @WolfX-700 ( https://www-l7audiolab-com.translat...l=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp) it makes no sense for me now to upload my own measurements here, but I got similar figures as they did, so this APU really shines and makes a great addition to anyone needing a cheap device to "upgrade" an existing ADC. Overall, the ADC offers outstanding value, both in terms of product design as well as high manufacturing quality. To my knowledge, this is currently the best performing ADC on the market. The only things that could be improved is the 2.5mm TRRS connector interface and the documentation. The high level input is a very important feature for me and therefore I'm going to use this connector most often. I have serious concerns with 60V on a tiny 2.5mmTRRS connector that may cause catastrophic failure in case this is (dis-) connected with signal present. REW https://www.roomeqwizard.com/ free for a single-channel version, that's enough for most cases. Not all versions correctly work with THD+N but RC9 at least is ok. The known issue is ASIO only supported, ASIO4ALL works ok but up to 192K. Sometimes ASIO4ALL driver can occupy Windows 10 volume slider after use, which makes it impossible to change the MONO/STEREO mode of ADC. Another nice option for REW is FlexASIO with 32/384 https://github.com/dechamps/FlexASIO/releases

it is a MONO ADC with summed Left+Right inputs mapped on the Left channel (Right input is always mapped to the Right channel). In the MONO mode, both channels need to be tied together L+ to R+, L- to R-."The Invert Second Output probably says something about the power supply regulation, although that might be crosstalk within the DAC chip, too. But, in two out of two DACs? Well, I asked about that in the E50 review thread. A fellow by the name of Rantapossu replied. He suggested that I activate L+R in the signal generator panel of REW rather than just use one channel. Look at the difference. This is E50 > Scaler > APU > ADCiso. Of course, the first thing I tried was the Noise level inherent to the equipment itself, with the inputs "on air", as well as short-circuited.

This is usually done by taking into account the width of the FFT window that is used to compute the levels for each frequency. One other useful feature you'll notice is the availability of +48V phantom power for condenser microphone input. There's a warning icon to make sure it's turned off when a line level device is plugged in as the voltage may cause damage.As further warning, there's an orange LED inside the 3.5mm phono input that lights up with phantom power engaged. Make sure to wait for it to fade (about 10-15 seconds) to indicate the voltage has been discharged before plugging in something like a DAC. Adding the second may bring you significant additional money, if you're into studio or wedding photography.Remember my unhappy observation about the Topping E50 performance as a test signal source? E50 Whining Remember that the input voltage for the APU's Preamp should be <=3.5Vrms, and <=10Vrms for Notch. Overvoltage of inputs may damage the unit, as a result, usually, input 0603 10ohm resistors will be burned. Of course, Cosmos ADC can be used as the finest vinyl ripping ADC or as a studio recording interface but I think pretty much any ADC may rip vinyl(just 70db of the 125db dynamic range needed) or record a mic's signal, where 16bits resolution, I guess is enough. In other words, Cosmos ADC is for sure breakthrough in audio measurement which becomes so attractively inexpensive and top-precise at the same time but regarding the vinyl ripping/studio recording, I don't think if you may notice the difference between an ADC with 10x times worse distortions VS Cosmos ADC. Regarding the grading, each Cosmos ADC unit is individually calibrated for the minimal distortions at level -0.5dbfs 1kHz with the typical THD <0.00003% or to say shorter .3-.2PPM. The typical level of 2nd, 3rd, and other harmonics between -135.. -145db for all grades from A to C. Grades are only about the noise, and each unit has a grade mark on the left side of the front panel. In most cases, SNR/Dynamic_Range in the MONO mode is within 127+/-1db(A) it is grade-B Cosmos ADC. Less than 126db(A) means grade-C, from 128db(A) and better grade-A, 129db(A) and better grade-0(very rare grade, and probably redundant, just in case). The MONO mode improves the SNR/DR for 3db, so a grade-A unit typically has SNR 125db(A) in STEREO mode. MONO/STEREO modes are switchable by the UAC2 volume commands, for example, if your Windows volume slider position is less than 50%(0 to 49%) the device works as 2 channel ADC, if more than 50% it is a MONO ADC with summed Left+Right inputs mapped on the Left channel(Right input is always mapped to the Right channel). In the MONO mode, both channels need to be tied together L+ to R+, L- to R-. THD@[email protected] BW 22-22kHz <.00003%(.3-.2PPM) typical for 32b/48kHz all harmonics level -135-145db