White PC-Engine RGB Mod CD-Audio

[herr-g]

Hi all,

i recently finished a sexy MiniDIN RGB mod for my favorite PC_Engine model.
Looks veeery beautiful indeed.
But i stumbled over a problem that i already know from many other PC-Engine RGB mods:
The Ext. Audio Pins don't carry the CD-Audio Siganals.

As the later Core 1 and 2 and SGrafx models have a nice mixed CD- and SFX-Signal on the AV-out my big question is how this can be done on the classic one.
I already figured out some points where a monaural mixed Audio-Signal exists,
but i couldn't find any useful solder points.

I would highly appreciate a solution for that?
I'm sure there has to be one, since the audio is carried out via the RF Signal as far as i know.

Kind regards,
 herr-g

[Lawrence]

1. The PCE's RF only does mono audio
2. the PCE only has mono audio input from the EXP connector
3. All PCE CD systems have audio out from the CD, not the PCE

Conclusion:

You should have put the RGB-output on the CD if you wanted to get stereo audio as well.  Your alternatives are re-using some pins on the EXP connector (there are a lot of extra GND and other pins that are never used) or simply getting audio from the CD and RGB from the PCE.

[Rockard]

herr-g: Can you show some pictures of your rgb-mod?
I would love to see! especially how the MiniDin is sitting on the circuit.
I made this specific mod myself, and somehow put the stuff inside the rf-box.
Did you do stereo also? Weak signals, eh?

OH btw, I didn't care for fumbling around with cd-audio and stuff, since I decided to NOT buy the case and hook it up to cd. I think that solution is so dodgy, ugly and big. The small white pce looks best by itself.

Instead I bought a Duo-Rx. So now I have the small pc-engine for, like, traveling purposes, bringing to game-parties and so.    

[herr-g]

Thank you both for your response.

@Lawrence
do you mean, the cd audio on the AV plug of the later PCE models is only monaural? I ever thought it was stereo. In that case you couldn't listen cd audio on your TV. I really can't imagine that.
Anyway, whenever i did an RGB mod on a core, sg or whatever PCE model i used the audio from the AV plug and now i just want to have the same result on the white one.
Aren't there any comparable solder points for l + r audio like on the later AV plugs?

@Rockard
Currently i only have the outer picture i made from that mod. Since i did it in service i don't have the machine anymore to take new pictures. If i can find some more i'll post them asap.
I simply took an 8-pin Contr. Connector from an old defective PCE PCB i found in my spareparts and soldered the whole thing upside down on the PCB. Therefore i had to drill four holes on ground points (just where the RF unit was) and soldered some wire on the metal housing of the MiniDin port (to work like sort of pins and GND shield). This way the port sits so tight that it will never break away when plugging or pulling the AV cable.
btw. if you don't have an old pce around (as in my case) you can take them out of the multiplayer adaptor. You just need any with a metal housing to solder on the pcb. It's better than any hot-glue or whatever solution.
How the hell did you manage to get the port in the rf unit?
I thought about that as an alternative but found it too difficult to manage.
I'd really love to see a picture of your mod as well :-)
If you don't want to post them, feel free to send them to herr-g@hamburg.de.

Regards,
 herr-g

[Lawrence]

do you mean, the cd audio on the AV plug of the later PCE models is only monaural? I ever thought it was stereo. In that case you couldn't listen cd audio on your TV. I really can't imagine that.

If you want stereo CD sound you have to use the AV jack on the CD system.  The CD unit can only feed mono sound back to the PCE, so if you use the AV output on the console instead of the CD, you only get mono CD sound, but stereo PCE sound.

[herr-g]

Alright, then the Core systems only carry mono cd-audio as well.
But how can i put the cd audio together with the sfx on the console?
Are there solder points for the mixed audio signals (Like that on the AV port)?
How can i get a solution that is comparable with the core's AV port audio signals on the white model?

herr-g

[Lawrence]

You can put the output on the CD system, or you can cut and re-wire the expansion connector on both the CD and PCE so that some unused pins become audio inputs.  There's no other way, really.

[herr-g]

Hi Lawrence,

i clearly understand what you mean.
In that case mono cd audio would be the best possible solution to get on the PCE side.
My goal is to get the best out of a PCE RGB mod without touching the CD system.
If stereo CD audio is not possible, then mono should be OK as well.
The question is how i can get the PCE SFX mixed with the (monaural) CD Audio like it is on the AV out of the core systems.
You know, i only want the audio to behave like on the AV port systems.

herr-g

[Lawrence]

The audio output of the PCE should already have the mono CD channel mixed in.  I'm not 100% sure of this.

[herr-g]

Unfortunately it isn't. And that's exactly the problem i have.
The audio l+r pins on the ext. bus only have the PCE's SFX, but no cd audio.
It's the same for all PCE models, not only the white one.
And it makes no difference what CD model you connect, as that seems to be some kind of specification.
That's why i always take the audio pins directly from the AV port when modding core and later models, but this one simply didn't exist on the early model.
Doesn't ever get anyone over that weird problem?
Or are there any alternate solder points for audio than on the ext. bus?
No more ideas anyone?

[Lawrence]

Ah, well no, of course the L+R pins on the expansion bus won't work, they feed the PCE audio to the CD, and the CD mixes it with CD audio and sends it back to the PCE.  If it was sent out the back AGAIN it'd result in an endless loop.

I'd try tapping the audio amp in the PCE, the little chip near the back, for the audio signals.