Project XI : Audio Analyser

[rumblinbass]

I did make my own AK5572 board after those comments above (went for AK5572 instead of AK5394 as it was about to become obsolete). Haven't optimised the BOM really but turned out working quite well and consistently getting THD+N peaking at -113dB, which by datasheet spec is great, and THD peaking at around -117dB, and DR 121dBA. I use OPA1632 to drive the input.

Input clamping and such are not the best in this though, limiting single-ended input level.

ADC AK5572 – Very high performance audio AD-converter – nihtila.com (link to schematic at the end)

I will probably make another version of that as there has been some interest and at the moment this board is a pain in the bum to assemble.

Thank you for the reply. I did visit your website last week and spend quite some time browsing through all of your projects. Very inspiring. I need to take some time reading through your write up about AK5572 measurements.

I am working on my own ADC with the AK5574 and also found the OPA1632. While researching I landed on this thread as well as another where someone buffered the 1632 output stating it's relatively weak output drive capability.
I understand that application is to be considered but I also know that ADC's can be deceivingly difficult to drive, particularly high frequencies at high levels.

 

[nihtila]

Thank you for the reply. I did visit your website last week and spend quite some time browsing through all of your projects. Very inspiring. I need to take some time reading through your write up about AK5572 measurements.

Thanks!

I am working on my own ADC with the AK5574 and also found the OPA1632. While researching I landed on this thread as well as another where someone buffered the 1632 output stating it's relatively weak output drive capability.
I understand that application is to be considered but I also know that ADC's can be deceivingly difficult to drive, particularly high frequencies at high levels.

Yeah I believe it can be tricky due to basically the buffer charging ADC sampling capacitor at several MHz. I got my takeaways to the buffer circuit from this article https://www.edn.com/audio-adc-buffer-design-secrets-interfacing-to-audio-adc-sampling-circuits/