1 (edited by Finfet 2022-09-08 10:47:34)

Topic: Digital bypass from ADI-2 Pro in AD/DA mode?

I plugged the AES/SPIDF break out cable into ADI-2 Pro, and connected the SPDIF coaxial in/out to my audio interface. All they others are working fine. Now I try to get the SPDIF optical out from ADI-2 to work in AD/DA mode but it seems not working. I think I set the optical out format and clock correctly as the SPDIF optical out works fine in USB and digital through mode.

I read the manual and find that there's no connection from digital input to digital output in AD/DA mode. Is there a way to work around it? Thank you!

2 (edited by KaiS 2022-09-08 10:50:46)

Re: Digital bypass from ADI-2 Pro in AD/DA mode?

Look at the block diagram manual page 38:
• Select AES at output 1/2.
• Switch digital out source.

Re: Digital bypass from ADI-2 Pro in AD/DA mode?

KaiS wrote:

Look at the block diagram manual page 38:
• Select AES at output 1/2.
• Switch digital out source.


Sorry for asking a question from just had a quick glance of the manual without reading it more carefully.

I switched the Digital Out Source - Main Out, then I can get digital output from optical.

But maybe my question will then change to is it possible to make the extra optical output act similar like PH3/4? (that can monitor the analog and digital input at the same time)

It seems I'll need to switch the Main Output to select the source, and there'd be no mixing of the analog 1/2 and digital input like the PH3/4 does.

4 (edited by KaiS 2022-09-08 19:51:04)

Re: Digital bypass from ADI-2 Pro in AD/DA mode?

Mixing means combining 2 different signals into one.
• There no mixing of any kind happening anywhere inside ADI-2 Pro.

• The digital outs are accessible from Output 1/2 or the analog input, but in no “Mode” from Output 3/4.


To find a solution you should tell us exactly what you’re heading for.
There might be options you don’t think of.

Re: Digital bypass from ADI-2 Pro in AD/DA mode?

I should've made it clearer. I actually do the routing in audio interface, not in ADI-2, to monitor the analog and digital input at the same time, from PH3/4. Here is my connection:

Analog path:
Analog 1/2 -> AD (ADI-2) -> SPDIF in(audio interface) -> SPDIF out(audio interface, mixer) -> SPDIF in (ADI-2) -> DA (ADI-2) -> PH3/4

Digital path:
System(Windows) -> SPDIF out(audio interface, mixer) -> SPDIF in (ADI-2) -> DA (ADI-2) -> PH3/4

When I set the Dig. Out to Default, the PH3/4 can perfectly get the mixed results from analog1/2 and system(win), one is analog and the other digital.

But optical output cannot act like the PH3/4. If I set the Dig. Out to Main Output, then the AD results from Analog 1/2 cannot be mixed in.

Looking at the diagram, I think I kind of know why (as there's no mixing happening in side ADI-2 Pro).

Using the PH3/4, I'm only monitoring the mixed SPDIF from my audio interface. The reason that it can be mixed, is because Dig. Out is at default, so analog->ADC can then pass to coaxial and then to my computer, mixed with the system's sound then output to SPDIF, which is then picked by PH3/4.

But when using optical out, we have to flip Dig.Out to Main Out (in this case, there'll be signal from optical, or there'll be no signal at all). But then optical can only get digital out from SPDIF, not from analog->ADC path. So if we do the same mix, the final results from SPDIF will only be the original SPDIF, mixed with a copied SPDIF going one round, which results in a louder signal converted only from the digital side.

I'm not sure if I made myself clear. I think looking closely to the diagram answered my question. Just wondering if there'll be a solution to this problem:
1. monitor the analog and digital input at the same time, from optical output on ADI-2 Pro.
2. with the help of an audio interface (consider it something like RME UCX, and no extra digital out available so the only way out is from ADI-2 Pro)