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| PSG improvement in SVI738?
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CrazyBoss
msx freak
Berichten: 144 |  Geplaatst: 26 Juli 2007, 23:10 |
Hello.
Now the first steps are done.
The Joystick port are fixed 
The 720kb drive are installed and working
Now its time to improve the sound. I remember maybe som resist have to be cut to improve the sound mixing.
Maybe the sound psg are damaged after all, cause the sound are a bit awfull 
-Claus-
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NYYRIKKI
msx master
Berichten: 1510 | Geplaatst: 27 Juli 2007, 01:49 |
No, that is normal for SVI-738 
Try to replace R2 (4.7Kohm) with something like 150 Kohm.
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CrazyBoss
msx freak
Berichten: 144 | Geplaatst: 27 Juli 2007, 10:27 |
Thanks, i remember in the past, some one told me maybe just cut some R. But maybe i wrong.
-Claus-
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NYYRIKKI
msx master
Berichten: 1510 | Geplaatst: 27 Juli 2007, 11:03 |
This is actually not a perfect solution, but I've used this as it's the most easy one. After this FM-PAC / SCC balance is quite right compared to PSG and PSG does not break the sound anymore. How ever key click may still be a bit too loud and because PSG volume is now quite low the noice from other electronics is louder.
I have not tried what would be the perfect solution, but to give you some hints:
Change R4 (56K key click sound) to bigger (maybe something like 100K)
Change R2 (4.7K PSG sound) to bigger (maybe something like 100K)
Change R6 (56K external sound) to smaller (maybe something like 20K)
If you have variable resistors I suggest using them and using your own ears to find a good combination. Then you can post your results here.  |
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CrazyBoss
msx freak
Berichten: 144 | Geplaatst: 27 Juli 2007, 21:35 |
ok i will give it a try next time i open the svi738
By the way the sound chips is from GI i think.
Is the Yamaha version better?
-Claus-
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