The Simple VCF was an early attempt to replicate the low-pass/high-pass filter from the original MFOS Sound Lab Mini-Synth.
The project went through many iterations, each exploring different ways to create the simplest possible yet fully functional VCF for DIY builders.
Every revision has its own character.
Revision History
0.3.2
- Added output buffer : Replaced U2 (TL072) by TL074
0.3.1
- Removed R18..R21 (U2A and U2B A=1)
- Added clipping LEDs D3 and D4 (resonance limitation)
- Lowered R22 to 100 (TBC)
0.3
- Removed U1 darlington stages
- Replaced by U2 FET opamps
0.2
- J2 (CV) normalization to ground removed (to lower the freq range)
- R12 to 1k to increase upper freq range
- Added R22 to reduce self oscillation
- R20 increased to 22k (higher output level for BP)
0.1 – Initial Release
- Imported from MFOS SLMS PLUS 0.2
- Removed all input potentiometers and connections to SLMS circuits
- Added two output Jacks with buffers
- Simplified values
