[sdiy] Akai S612 filter/schematics

[Joris]

Sean Ellis:


> You will need to add a feedback path (with VCA) to each of the MF6CN
> switched cap filters, shouldn't be too hard. I don't have schematics
but you
> could get away without them for this.

Aha, thanks for the hint!

It seems a bit silly that there actually are 6 filters (one for each
voice) considering that the S612 has no filter envelope, but I guess
this was needed to accomodate for the seperate outs.

Btw from the data sheets ( http://www.national.com/ds/MF/MF6.pdf ) it
seems like there is no resonance peak in these lowpass filters, but my
ears tell me there *is*. Any thoughts on this?

Also on page 16 of the datasheets there is an example for using the
MF6CN as a notch filter; that seems like a interesting mod.

> Was there someone on the list a little while ago who mentioned a
'split
> mode' modification for this sampler? I may have just dreamt this
though ;)

Seems like that would involve hacking the OS in the Eprom. If someone
has a go at this (s)he might as well try and add some sort of SDS
sysex functionality to dump samples over midi.

Joris