DP -> adat out -> adat in -> DP ... 32bit->24-->32bit???

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mwilloam
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DP -> adat out -> adat in -> DP ... 32bit->24-->32bit???

Post by mwilloam »

Quick question about what people know about the signal stream hopefully explained in the subject line. Just to try something I setup my 828's adatA bank to act as a loopback so I could clip certain tracks in realtime without a plugin. Not looking to get into discussion about clipping or plugins vs converters etc ... just curious about any bit depth changes with the routing above and any sonic/technical implications, theoretically.

If I have audio in DP I can route internally all at 32bit float up until I hit a convertor out which alters it to 24bit fixed(my understanding). Is this the same with adat? Would that mean by using the routing explained above it's actually truncating the audio and then re-upconverting it to 32bit float on re-rentry in DP? Thanks.
EMRR
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Re: DP -> adat out -> adat in -> DP ... 32bit->24-->32bit???

Post by EMRR »

I believe the ADAT standard only allows for 24 bit words, so it would truncate.
Doug Williams
Electromagnetic Radiation Recorders
The Martha Bassett Show broadcast mixer
Tape Op issue 73

DP 11.31
Studio M1 Max OS12.7.3
MOTU 16A and Monitor 8
M1 Pro MBP for remotes and editing
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bayswater
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Re: DP -> adat out -> adat in -> DP ... 32bit->24-->32bit???

Post by bayswater »

I don't see how this would different from routing anything in and out of DP. While the internal processing in the MAS engine might be at 32 bit float, anything leaving MAS will be at 24 bit. So the question is what DP does with a 32 bit signal when it leaves the MAS engine -- dither or truncate.

I sometimes use this signal path to run audio from DP on one Mac to another Mac via ADAT using a MOTU interface for processing, and back to the first Mac via ADAT. Works fine as long as I don't use ADAT as the clock source.
2018 Mini i7 32G 10.14.6, DP 11.3, Mixbus 9, Logic 10.5, Scarlett 18i8
mwilloam
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Re: DP -> adat out -> adat in -> DP ... 32bit->24-->32bit???

Post by mwilloam »

EMRR wrote:I believe the ADAT standard only allows for 24 bit words, so it would truncate.
Makes sense.
mwilloam
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Re: DP -> adat out -> adat in -> DP ... 32bit->24-->32bit???

Post by mwilloam »

bayswater wrote:I don't see how this would different from routing anything in and out of DP. While the internal processing in the MAS engine might be at 32 bit float, anything leaving MAS will be at 24 bit. So the question is what DP does with a 32 bit signal when it leaves the MAS engine -- dither or truncate.

I sometimes use this signal path to run audio from DP on one Mac to another Mac via ADAT using a MOTU interface for processing, and back to the first Mac via ADAT. Works fine as long as I don't use ADAT as the clock source.
I'm guessing truncate. Would be interesting if DP could enable a computer to serve as an AVB device itself so you could route audio between them with ethernet alone.
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bayswater
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Re: DP -> adat out -> adat in -> DP ... 32bit->24-->32bit???

Post by bayswater »

mwilloam wrote:
bayswater wrote:I don't see how this would different from routing anything in and out of DP. While the internal processing in the MAS engine might be at 32 bit float, anything leaving MAS will be at 24 bit. So the question is what DP does with a 32 bit signal when it leaves the MAS engine -- dither or truncate.

I sometimes use this signal path to run audio from DP on one Mac to another Mac via ADAT using a MOTU interface for processing, and back to the first Mac via ADAT. Works fine as long as I don't use ADAT as the clock source.
I'm guessing truncate. Would be interesting if DP could enable a computer to serve as an AVB device itself so you could route audio between them with ethernet alone.
Sure, but it would probably still be 24 bit. If you search around here you'll find out whether it is truncate or dither. For all practical purposes I don't think it matters.

The first item in the Audio menu is a Dither setting. You could see if that makes any difference to the 24th bit with a null test between the original signal in DP and the one that comes back over ADAT.
2018 Mini i7 32G 10.14.6, DP 11.3, Mixbus 9, Logic 10.5, Scarlett 18i8
EMRR
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Re: DP -> adat out -> adat in -> DP ... 32bit->24-->32bit???

Post by EMRR »

AVB transmits/receives 32 bit words, so the AVB devices will take DP's 32 bit path (if set that way) and apparently dither/attenuate/etc at the DA chip. It's in the DA chip spec.
Doug Williams
Electromagnetic Radiation Recorders
The Martha Bassett Show broadcast mixer
Tape Op issue 73

DP 11.31
Studio M1 Max OS12.7.3
MOTU 16A and Monitor 8
M1 Pro MBP for remotes and editing
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