Topic: is the ADI-2 Pro really 32-bit through the entire signal path?

I have read that many 32-bit DACs actually truncate to 24 bit within the DAC chip before reaching the Converter itself.
is this also the case with the ADI-2 Pro fs?

2 (edited by KaiS 2022-07-26 14:11:18)

Re: is the ADI-2 Pro really 32-bit through the entire signal path?

No, ADI-2 internally it‘s 42 bit, 3 bits of which are used for 24 dB internal level headroom.

Read ADI-2‘s manual page 66 (DAC) 93 (Pro), last line:

RME's digital volume control in 42 bit TotalMix technology avoids all the disadvantages of analog level control via pots, is easy to use, offers reproducible settings, and the highest sound quality.

A 24 bit truncation in the DAC chip would not allow the clean performance shown in the measurements on the same page - no distortions at -93.8 dB volume.

At -93.8 dB attenuation a 24 bit signal would show ca. 0.5% or -46 dB distortion relative to signal level, or -150 dB absolute.
The chart reaches down to -190 dB.

3

Re: is the ADI-2 Pro really 32-bit through the entire signal path?

hasan.ay386 wrote:

I have read that many 32-bit DACs actually truncate to 24 bit within the DAC chip before reaching the Converter itself.
is this also the case with the ADI-2 Pro fs?

Tales from the past....

Regards
Matthias Carstens
RME

4 (edited by hasan.ay386 2022-07-27 09:48:43)

Re: is the ADI-2 Pro really 32-bit through the entire signal path?

KaiS wrote:

A 24 bit truncation in the DAC chip would not allow the clean performance shown in the measurements on the same page - no distortions at -93.8 dB volume.

Wow! Thanks

so the signal path would be like this?
24bit file → 42 bit internal volume control → 32 bit DAC

Re: is the ADI-2 Pro really 32-bit through the entire signal path?

whatever file -> 32 bit USB interface / 24 bit digital interface -> (optional 32 bit SRC) -> 42 bit DSP -> 32bit DAC.

6

Re: is the ADI-2 Pro really 32-bit through the entire signal path?

Small correction - the SRC is 24 bit, and gets fed only 24 bit (via SPDIDF/AES/ADAT).

Regards
Matthias Carstens
RME

Re: is the ADI-2 Pro really 32-bit through the entire signal path?

MC is always correct. I searched AK4127VF's datasheet from digikey (https://www.digikey.com/en/products/det … VF/2538694), whose download button gives what is actually 4137's datasheet.  -_-

Re: is the ADI-2 Pro really 32-bit through the entire signal path?

Thanks!