PURIFI EVAL2 Eigentakt Mono Amplifier Kit

[pma]

PURIFI EVAL2 Eigentakt Mono Amplifier Kit​

I bought this kit from Soundimports

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I had some troubles with the first kit, it would not start switching. However, Soundimports customer support were very helpful and they sent me after return a replacement unit, that is working fine. Highly appreciated!

I did not want to buy another expensive component immediately without testing the kit (SMPS SMPS1200A400, another 240 EUR), so I am testing the kit with my linear supplies. 2x46V as Vp, 2x15V as VOP and 1x15V as VDR. I also tried 2x60V Vp to check maximum power. I have some first results and they are looking good as expected. Later I would like to test the kit with complex impedances and to measure HF switching residuals.

My setup

Some measurements

I am having stability issues of REW software with ASIO4ALL and Topping/Cosmos combo, so I am rather posting ARTA measurements that are stable.

Sound

The sound is perfect, precise, no colorations, no noise.

 

[staticV3]

I am having stability issues of REW software with ASIO4ALL and Topping/Cosmos combo, so I am rather posting ARTA measurements that are stable.

Use Java EXCL.
Same bit-perfect audio transmission as ASIO, but much more stable.
And no need for extra software to create aggregate devices.

 

[pma]

Use Java EXCL.

I will try again. It did not work for me. Can I use it for 2 different devices, DAC and ADC?

 

[staticV3]

Can I use it for 2 different devices, DAC and ADC?

Yes.

 

[Multicore]

I'm not familiar with the 3.18 kHz square + 15 kHz sine test signal. What's the idea with that and what sort of things should I be looking out for in the spectrum?

 

[NTK]

I'm not familiar with the 3.18 kHz square + 15 kHz sine test signal. What's the idea with that and what sort of things should I be looking out for in the spectrum?

The section on the Sine-Square test in this paper describes what the test does (it is for TIM transient intermodulation Distortions or DIM Dynamic Intermodulation Distortions).

https://www.researchgate.net/publication/277870128_A_Comparison_of_Nonlinear_Distortion_Measurement_Methods

 

[pma]

Some more measurements.

THD vs. frequency at 100W/4ohm and 48kHz measurement bandwidth

Measurements of 500kHz switching residuals

Purifi has by far cleanest HF spectrum from the class D amplifiers that I have measured so far. I even do not need to use a LC low pass filter for my Cosmos ADC. The spectrum is much cleaner than that of my PMA-NC252MP.

 

[phofman]

Can I use it for 2 different devices, DAC and ADC?

Actually, that's what standard ASIO cannot do correctly, for two separately-clocked devices. Perhaps that was the cause of the stability issues with ASIO4All.

WASAPI (as all other proper audio APIs) does not bind capture with playback and allows asynchronously-running devices on each side.

 

[pma]

WASAPI (as all other proper audio APIs) does not bind capture with playback and allows asynchronously-running devices on each side.

Thank you. I have updated the REW to the latest version, however, I still do not get the choice option of Wasapi exclusive. Only ASIO or Java, and under Java only basic WDM drivers.

 

[staticV3]

Thank you. I have updated the REW to the latest version, however, I still do not get the choice option of Wasapi exclusive. Only ASIO or Java, and under Java only basic WDM drivers.

Java EXCL = Wasapi Exclusive.

 

[pma]

Java EXCL = Wasapi Exclusive.

I see, but I have no such option visible in REW.

 

[staticV3]

I see, but I have no such option visible in REW.

Are you certain?

 

[pma]

Are you certain?
View attachment 373395

Absolutely sure.

BTW, I have Windows 8.1
Java is installed.

 

[staticV3]

Absolutely sure.

View attachment 373397

BTW, I have Windows 8.1
Java is installed.

Which REW version?

Newest is V5.31.1

 

[pma]

V5.31.1
Installed today. Please let us not check the trivialities.

 

[staticV3]

V5.31.1
Installed today. Please let us not check the trivialities.

Interesting. Thank you for checking!

@JohnPM Is it expected for Java EXCL options to be missing from REW when run on Windows 8.1?

 

[phofman]

@pma : Do you have exclusive access allowed for your devices? E.g. https://help.uaudio.com/hc/en-us/ar...e-Exclusive-Mode-in-Windows-Sound-Preferences

 

[pma]

Of course I do.

BTW, wasapi works in both Audacity and Foobar for me. Both needed to have an appropriate component installed.

 

[phofman]

32 or 64 bit windows?

 

[pma]

Windows is 64 bit, but REW installation is 32 bit.

Thank you, @phofman , that was the issue. 64 bit installation works with wasapi!