DM VCF - Discrete Multimode VC Filter

Discrete State-Variable Multimode 24 dB/oct VC Filter.

State-variable filter is 12 dB. To get 24 dB is needed to place two 12 dB filters in series, as I made in my DD VCF. But then both 12 dB filters have resonance loops, so the resonance has double loudnes.
I wanted to solve that and make 24 dB State-Variable filter more 'correct'.
So I installed dual gain cells and got single 24 dB State-Variable filter.
The filter works very correct. It has stable equal loudness resonance and selfoscillation in full frequency range.
So who wants very correct preciese filter. This is it.
I think nobody makes this way, I never saw.
As other L-1 discrete filters, the circuit is based on original Discrete Blacksea gain cells and best silver-mica capacitors.

Features:
Discrete multimode voltage controlled filter.
4 of Discrete Blacksea gain cells in the core.
4 of best quality silver-mica capacitors.
LP, BP, HP outputs.
State-Variable filter with dual gain cells provides 24dB/oct filtering with control over frequency and resonance.
Full voltage control over cutoff frequency and resonance level.
1V/oct standard frequency control.
Stable, equal loudness resonance and selfoscillation in full frequency rtange.

http://l-1.su/DMVCF.html