Hi all!
And sorry for bringing up this subject in Yet Another Thread but I've read the others, and also this - and still my 8250 is not fixed ;) I'd like to fix this, and perhaps some other Philips NMS's can be also fixed if I can get this fixed with someones help =)
To summarize the problem - PSG is nearly silent when ANY SCC cart is inserted - :
- I've changed R428 and R429 to elco's
- C119 polarity was already correct (different to C121 on the PCB) and R174 is already 910Ω.
- Sometimes there ware quality problems in SCC audio (see link)
- Philips FMPAC does not change the PSG level (noticeably)
- Philips FMPAC is quiet (as PSG) if used together with an SCC cart
Possible remedies:
- I'm thinking about changing R170. Does anyone have any idea, what value I should put there?
- I've read in other threads to put a potentiometer in pin 49. But I don't like that fix, I'd rather put some resistor with a fixed value; but also, why is FMPAC level correct? Will the potentiometer make the FMPAC level wrong? But if this is the only way, then I guess that's what I'll need to do.
- ???
I've made a recording on the SCC quality issue (notice missing PSG, but also the crackling sound). I have not noticed any quality issues on other software than the SD Snatcher, and in SD Snatcher only in the recorded part (actually there might be very slight issues earlier in the intro, too, but they are nearly inaudible). On an emulator the sound is nice in SD Snatcher. But also I have no other MSX2 to compare with, what SD Snatcher should sound like in a real MSX2...
Thanks! Hope someone has an idea what to do next. LOL!

). Hmm., maybe I should test it on OpenMSX with a regular emulated SCC instead of SCC+ 
. Maybe it sounds like this even originally, so never mind about that - I must have had some earwax, I could have sworn it sounded better at that part in OpenMSX
