5pole diode filter (was:Re: Re(2): [sdiy] Another CV breakthrough question)

[jh.]

> And there were two versions of the filter board. I have schems with both
> filter boards, but the only real difference is that one uses the moog
> ladder and the other uses the diode/transistor ladder. The diode ladder
> filter is the same as the Sys-101/102, but the diff amp is the same
> horrible one opamp thing. They must have learnt about better diff amps
> by the time the much better System-100 came out. The Sys-101 uses the
> same discrete diff amp as the TB303 more or less.
>
> Now the Sys-101 is one of my favourite synths, so I'm keeping the diode
> ladder filter in my SH-2000. However, I think I am going to match the
> transistors better in the ladder to get rid of the that CV breakthrough.


So the System 100 has a 5-pole diode ladder, too - I didn't know that.
The SH-5 has it as well if memory serves.
Guess I have to build one of these, too - never tried it so far.

How would you describe the sound ? I'd expect it to have a similar
slope as a 4pole transistor ladder, and even more bass reduction
with increased resonance ?

Regards,

JH.