[sdiy] IR3R05 - MKS80

[media at mail1.nai.net]

At 10:14 AM +0100 06/05/01, Emmanuel Amadio wrote:
>
>Hi fellow list members !

Yo!

>Does anyone know how this Roland chip is used in the MKS80 ?

Yes, it replaces parts of the VCF and VCA that used the IR3109 and CEM3360
in the earlier versions.

The IR3R05 contains two 12db/Oct state-variable filters (BP and LP), and a
VCA with both linear and exponential inputs.

>Can anyone point me to a schematic (or send me one) ?
>Thanks.

I don't have a schematic of the IC, but these are the pinouts (which should
give you an idea what is going on inside it):

1. Input
2. Freq (CV VCF)
3. Resonance (CV VCF)
4. linear (CV VCA)
5. exponential (CV VCA)
6. Load (resitor and cap to ground -- hard to read)
7. Vee (-15V)

8. Output
9. Ground
10. C4 (220pF to ground)
11. C3 (220pF to ground)
12. C2 (220pF to ground)
13. C1 (220pF to ground)
14. Vcc (+15V)