Best Way to Pull Stereo Signal 8y RS3

[FSTSNAL]

Just trying to find the best way to get a clean, flat signal for a stereo upgrade in my 8y. In the past I would have used MOST, but in Audi's wisdom they removed it from 8y. AFAIK there is no CAN adapter to pull audio or ethernet so let me know the best way to do this. LOC? Summed channels? Thanks

[Smac770]

8Y uses MIB3. MIB3 uses the internal amplifier in the J794 solely, unless B&O is implemented. In that case, the J794 supplies 8 output channels and the J525 supplies 8 output channels. The J525 is just a slave amp device in MIB3, it's not on the CAN bus. J794 to J525 is via A2B, not MOST (and not the Ethernet/Flexray pins). MOST on MLB MIB3 is there for other reasons, not audio signal transfer like MMI2/3 and MIB1/2. Since it has no need to transfer source audio to another device in any configuration, there's no source audio output from the J794.

If you google search for Audi SSP 970893 and look at page 22, you'll see the MIB3 B&O layout. I don't know if the A2B would be simply 4-ch source audio and the J525 performs the DSP to produce the channel specific signals for the amp channels. Or if the J794 is doing all the DSP and shipping the eight processed channels and the J525 is literally just an 8-ch amp. I would expect the latter. But you'd need an A2B sniffer and decoder to really confirm.

As such, you're pretty much stuck reprocessing the amplified outputs of the stock J794 and J525, I suspect.

[FSTSNAL]

Thanks. I just reached out to navtv. They seem to have an a2b adapter for ford and their most150 adapter decodes a2b from most on mlb on 2020 and 2021 Audis according to some

[SVTunit]

8Y uses MIB3. MIB3 uses the internal amplifier in the J794 solely, unless B&O is implemented. In that case, the J794 supplies 8 output channels and the J525 supplies 8 output channels. The J525 is just a slave amp device in MIB3, it's not on the CAN bus. J794 to J525 is via A2B, not MOST (and not the Ethernet/Flexray pins). MOST on MLB MIB3 is there for other reasons, not audio signal transfer like MMI2/3 and MIB1/2. Since it has no need to transfer source audio to another device in any configuration, there's no source audio output from the J794.

If you google search for Audi SSP 970893 and look at page 22, you'll see the MIB3 B&O layout. I don't know if the A2B would be simply 4-ch source audio and the J525 performs the DSP to produce the channel specific signals for the amp channels. Or if the J794 is doing all the DSP and shipping the eight processed channels and the J525 is literally just an 8-ch amp. I would expect the latter. But you'd need an A2B sniffer and decoder to really confirm.

As such, you're pretty much stuck reprocessing the amplified outputs of the stock J794 and J525, I suspect.

@Smac770 I have the B&O system, looks like there is now way to pull an "Unprocessed" signal from the J794?