Which tells me there are smarter people in Europe than in the Americas when it comes to knowing the value of a rare commodity.

If you go ahead w/ the ADP-303 mod, it will still be worth it in that case. Been thinking of getting the Marantz equivalent to fumble around modding it but can’t find it cheap enough to make it worth my while right now.

I just modded one of these. Here are images of the AC-3 board and where I tapped the signal from.

Cool

What pin on what chip does this point go to? I have been researching the Marantz version (DP-870) and can't decide if pin 35 (Data-O) or Pin 39 (DO) would be the right point off of the DA1 chip (LC8904Q). This is what I would hope is the point after input switching.

65 on the Pioneer chip. I tried pin 35 on LC8904Q with no results.

Did more research on that DA1 chip and now I am thinking the digital out could be pin 1. Here is a schematic I found on the chip.





On the schematic for the Marantz, DP-870, the pin is currently not connected to anything so that could be a good hint it's the correct point.

Same for the ADP303. I definitely overlooked that. I might give it a shot.

I tried pin 1 with no success.

Well.... it was worth a shot. Back to the drawing board

Thanks for checking

I wish we could get a kit made (printed board, passive components, and enclosure) where all we would have to do is solder a donor Pioneer demodulation IC.

I think the Onkyo ED-901 has the same signal on pin 65 if you want to add a digital out.

stumbled upon such a standard factory fitted db-25 decoder.

Opening up the unit later on and have a look

Interesting on the DB25 connector. It looks like it is just 5.1 out though from the SM.

The DB25 was the other option to having six standard RCA cables mated from a processor to an AV Receiver or AV Pre-Amp. They essentially function in the same manner. There is still no digital output from a DB-25.

If one ends up w/ the ED-901, you can make or even purchase an adapter that goes from DB-25 to six RCA cables. Here is an example of one...

https://www.infinitecables.com/audio-an ... hx-pinout/




Now I'm thinking these processors that utilize the LC8904Q chip are not designed to accommodate with any ease the inclusion of a digital output. I know that the kit I purchased to add a digital out to my CLD-M90 had a very extensive list of chips that would work with it but not the LC8904Q. At most, the digital out signal on LC8904Q might be coming off of several pins that might need to be combined in a special manner on a secondary board to create a proper S/PDIF digital signal. Gotta do more research on it.

Yeah my Kenwood has the DB25 between the preamp and amp. Your posts remind me I need to see if I can find one in storage to free up some RCA cables.

the chip in the HK-303 and ED-901 look the same if you ask me...

have to open up the unit to make sure

expensive cables!
even has the wrong male DB-25 connector.... need female to rca if you want to set it up that way.I it is for use towards a receiver I think.... 5.1rca out to db-25 input
I have no use for the ed-901 tbh. but I might add a digital output just for the sake of science...

Located the 4606 IC chip on the ED-901 . There is a solderpoint signal path on the actual board.
This should be easy enough to tap

I'm getting working AC-3 directly from PD4606A pin 65. From what I have seen, if you do digital coax you would really need to make a small board for all of the downstream components. I'm going to go the TOSLINK route, so I think I can just add the connector and tap VCC and GND and be good?

This is all based on my (probably incorrect) reading of the APD-1 service manual.

For Ref :

The Yamaha DDP-1 Demodulator also uses the Pioneer PD4606A - so should also be moddable for a Digital Out....that would be handy for me as then I can then make use of sound delay configuration on my receiver.

Did you get this working CPP ?

Oooooooh, I'm in on this! I have a Yamaha DDP-1 that needs to have this mod installed. So to recap, pin 65 on the chip? Then connect my grounds (one from coax pigtail and the other from the +5V power lead?)

I'm using this - https://www.ebay.com/itm/323774426627?V ... 3774426627

This would be so cool and really bring up the popularity of processors since they could go from 5.1 out only to a digital out.