PCCM+ MOST box defective?

[laalves]

To anyone who installed a PCCM+ in a MOST 996/986, when you initially attached the MOST box, could you see red light inside the socket when the radio powered up? I have no red light shinning at all.
And, for anyone who has currently such a setup, can you check whether the MOST version number shows up in the version info screen? For comparison, I'm attaching a photo of my version info screen, MOST version empty.
It appears the PCCM+ does not detect the MOST box. I read about a lot of cases where the MOST box was DOA, I'm wondering if I have another such case.
My car is non-MOST and am not going to use it initially at leat but given I have an aftermarket amp with a Toslink input (and only speaker-level inputs, no line-level) I was thinking about getting a MOST to Toslink converter and ensure a fully digital path to the amp. The way it will be now, the PCCM+ converts the iPhone digital stream to analog, amplifies it to speaker level and then it goes down the line to the amp, where it will be digitised again, processed by the DSP stage, converted back to analog and amplified again and finally sent to the speakers. So, I was definitely considering using a fully digital path but that requires a working MOST output.

So, can someone please check their "Version Info" screen and see if their MOST shows a version or is also empty, despite working fine?

[Teddlington]

Maybe this doesn't quite answer your question because a) it's dark outside now, and b) I don't fancy the grief of pulling my HU out to check - but:

 

My CDC-4 lights up when powered but not connected,

My Bose amplifier lights up when powered but not connected,

my Mr12Volt bluetooth / USB / SD / Line in interface lights up when powered but not connected, and;

My PCM2 used to light up when powered but not connected.

I would deduce from this (and the light read through the MOST technical specification 🤓) is that the MOST box supplied with the PCCM+ must light up, otherwise it isn't transmitting on the network and will in fact cause the entire network to fail (all signals pass through, and are replicated by, every device on the loop).

 

• Check the connection from the HU to the MOST unit is actually connected and seated properly (without sounding too patronising).
• If that isn't it then there is a setting in one of the hidden menus to turn MOST off, this might cut power to the box, check this isnt switched off too. You'll need to (very) long press "Version Info" to get the menu up.
• Failing that, give the vendor a nudge and see if they can spot you a replacement MOST unit. I think they have their own part number so I would suspect Porsche can provide the unit by itself.

I do get some information in the MOST row of that screen though. I'd have remembered if it was blank.

 

I can't necessarily speak for sound quality over TOSLINK, I just left mine with MOST as it was easy from an integration perspective. Fundamentally it should be fine as it's capable of linear PCM signal and the iphone over USB connection is also I think PCM and generally regarded as pretty much lossless. You do however have an electrical to optical conversion at the HU, then optical-electrical-signal conversion-electrical-optical in your MOST/TOSLINK convertor, then a conversion back from optical to electrical - how good this circuitry is on the HU, MOST to TOSLINK converter, or your amp when it comes to packet loss and jitter could be a bit of an unknown. The only brand name MOST to TOSLINK I could find when I went through the same thought process was an Audison one which was big dollar (how much of that is just Hi-Fi tax, I dont know).

[laalves]

Thx! My case is that my car is not MOST, it was analog Bose (MY02 Turbo). So, I was considering using the MOST box to supply any of the available options in the market: Trioma (russian, cheapest), Audison (apparently made by Mobridge) and Mobridge itself. All are expensive but I've spent a lot of money in HiFi, cars, booze and XXXX (redacted) so it would be just a bit more of that 😁

 

Will check the cable for continuity as well.