Marantz DP870 Digital Out Mod Success!
Works fine!

A lot tighter to fit in - Height of the Module is a challenge.

Hey D770, I'm modding a Marantz-DP870 right now. I pinpointed where I need to solder, but wow those holes are small.

Do you have any pictures of where you soldered the coax lead to? I'm sending you a DM as well in case you don't see this.

Photo here for the curious ones.

PD4606A Board with Pin 65 highlighted in red


Audio Board Side A


Audio Board Side B

Hi ldstl Just had a look what I did... seems I tapped into the DAOUT by soldering to one side of RR01 (Audio Board side B (DAOUT side)) - check with meter if you choose to do the same - I recall not wanting to dismantle further anything if possible...I managed to get a good connection then clamping the coax/signal cable down to the Audio circuit board with hot glue in several places to support the soldered joint. Of course there are many ways to do this..as you have the board out perhaps its better to insert a PCB terminal Pin in one of those visible in circuit holes nearer the Pioneer Chip and solder that in for a good Connection. I recall also the limited length of the Mod PCB wires...so for me it was done as easy and as quickly as possible. Hope that helps.

It has been a while!

What did I do....

First, the standard mod, tapping the signal for digital out from the IC...
Next, I disconnected the optical input and took that signal line to the switcher I made.
Also the tapped signal for digital ot from the IC is going to that switcher.
To trigger the switcher, I've simply used the "AC3 RF" LED signal.... (When the ADP-303 detects a valid RF signal, the LED will lit up).
I did have to buffer it to trigger the switch.
So when the LED is lit, the switch takes the digital signal from the IC and directs it to the optical out (that was added on the back).
When the LED isn't lit, the switch takes the signal from the optical input and directs it to the digital out.

Works perfectly!
Only downfall is, the ADP-303 can't take signals from the optical input to convert it to analog anymore... (coax in will still work, as does the AC3RF...) But that's not really a problem

I've just picked up another ADP-303 for only 30 Euro.. Not shure if I'm going to mod it, or keep it original... We'll see.

I've been looking into the possibility that we need an I2S based digital output module to make a connection from the LC8904Q to create a digital out that works w/ all the digital inputs including the AC3-RF input to truly make a DP-870 and ADP-303 into a more usable device. Here is what I have been contemplating @ this point.,,,

A seller on ebay is now offering this new type of S/PDIF board that utilizes I2S.....

https://www.ebay.com/itm/225471147772

I looked over the points that are needed to make this board work as noted....



.... and was able to find what I think works on the IC....



The MCLK point I'm uncertain about but I think CLKOUT2 could be it based on what the SM says about the data coming out of it seems to pertain to what is required for the main clock. For power, I did not research it but that should be easy to find anywhere in the processor.

In any case, I'm still seeing about obtaining either of these processors and then will go about trying this mod. If anyone wants to try on their own (just remember that I'm only guessing so don't hold me to it if you break it), please let me know your findings.

Addendum……

Well, after more research, I did find that CLKOUT2 is indeed the master clock as I followed the trace back to connector J602 as noted……



Also, turns out the other two clock points also go to this connector which would make it easy to solder wires to (the data out point would still need to be soldered directly to the chip unless there is a larger solder point between it and the Zoran chip.

In any case, turns out I will be receiving a Marantz, DP-870 soon and now I will see about getting this mod tested. Stay tuned as I will create a new post if it works.