Not magic. All perfectly explainable. But sometimes it is 'an inconvenient truth' and the cognitive dissonance can be made to go away by pretending it's just magic 😎
Jan
Jan
I almost sure that human brain can do very difficalt different sound post-processing, which can extend our possibilities to something much lower tban -90 dB.
Actually you might be able to use the AP software with a QA401. Its not quite as good as an RTX but quite available and has the hardware interface for audio testing. I can get -109 dB THD pretty consistently with one. The SNR/dynamic range is not what you can get with a dedicated analyzer but no ADC based device can do that. They aren't in the Focusrite price range but still less than a Lynx E22 and I think higher performance in some areas.
The AK5934A which is the magic in the RTX (and the AP515 ?) has been discontinued so everyone will be looking for a replacement. Dead giveaway that the ADC is not the AK5934A is the rising noise floor at HF.
When I tried to get the ESS ADC running the performance was quite poor. I contacted ESS and they could not help me get better results. I sent the demo board back and the chip seems to have vanished without a trace.
The AK5934A which is the magic in the RTX (and the AP515 ?) has been discontinued so everyone will be looking for a replacement. Dead giveaway that the ADC is not the AK5934A is the rising noise floor at HF.
When I tried to get the ESS ADC running the performance was quite poor. I contacted ESS and they could not help me get better results. I sent the demo board back and the chip seems to have vanished without a trace.
Ask Dolby about that!
On the other hand, unless we listen to a continuous tone, music isn't necessarily waiting for our brain to accommodate...
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Yes, most probably the APx500 Flex will work with the QA401, the requirement seems to be ASIO compatibility.
The 2722 gets its very low residual (2nd at 1kHz -136dBr on a good day) from using an analog notch with post-notch gain and throwing that at a DAC. That lowers the dynamic range requirement for the DAC by at least 60dB.
That is what I try to emulate with my tracking notch filter. Which seems to work but I haven't been able to work on it for a month due to other (paying) obligations.
Jan
If you have Glen Kleinschmidt aproval, as i don't even know how to contact him, i can post here his -120thd analyzer schematics.
Has anybody tried what's on page 10-15 of this?https://www.analog.com/media/en/technical-documentation/application-notes/5866763300941AN245.pdf
Do you know the mystery of APx555 used ADC chip's 😀
May no one opened the hard locked closing yet, otherwise loosing the proofed calibration 😱
Hp
With a good analog front end and notch filters you don't need the same performance ADC. I suspect that uses an industrial wide band ADC.
What a smart idea - And you can trust your doubts, also. Because for shure you will be disappointed. AK4499 is not an AD converter. It's someting else. Guess what ...
It seems the package was discontinued so they did not want to layout a new chip to work with newer packages. It's not a highly profitable market with small volumes.
Jan I'd stumbled accross this thread whilst researching getting a new sound card, and I've just now in another thread remembered about something someone showed me a few years ago which is probably in the ball park of what you are looking for (if not a tad on the expensive side).
ADI-2-Pro FS - RME Audio Interfaces | Format Converters | Preamps | Network Audio & MADI Solutions
Tony.
ADI-2-Pro FS - RME Audio Interfaces | Format Converters | Preamps | Network Audio & MADI Solutions
Tony.