Roland SH-5 Dual Filter Adaptation

All of the phat and none of the chaff.

WHAT's DIFFERENT IN VERSION 2
No on-board front-end sub-mixer means you can use your own stereo- and matrix-mixers to distribute incoming signals between the VCF/BPF any way you like. My upcoming Influx mixer (sold separately) will be a perfect companion.
Removed the CV circuitry from the BPF, restoring the original frequency response without dropouts and thumps. Also improving the top end resonance characteristic more in line with the original synth response.
2 CV modulations for VCF Cutoff Frequency, instead of 3.
Slightly less width at 14HP.
More skiff friendly at 25mm module depth.
Better price.

WHAT's THE SAME IN VERSION 2
The VCF circuitry was exquisite the way it was, and remains exactly the same in version 2.

SH5-VCF r2 is an all analog Eurorack adaptation of the Roland SH-5 Dual Filter. There are no filters-on-a-chip here. The SH5-VCF r2 uses all discrete components and quality op-amps to work its special mojo. Like on the original synth, the Low Pass circuit is comprised of open-collector matched transistor pairs arranged in a diode ladder configuration. This same configuration used in the Roland SH-1000 and the earlier System 100 (not 100m).

THE DUAL FILTERS: VCF + BPF
| VCF | The VCF (Voltage Controlled Filter) comprises one HP (High Pass) and one LP (Low Pass) circuit in series. VCF Select switch can choose 1) HP, 2) LP, or 3) BP (Band-Pass) configuration. Due to the unique design, the HP resonance is actually derived by overdriving the LP circuit.
| BPF | The dedicated BPF (Band Pass Filter) has its own discrete circuit distinct and apart from the VCF. The original BPF circuit has been respected. The BPF Level attenuator will affect the MIX output only.

VCF/BPF INPUT/OUTPUT
A signal going into the VCF jack will also appear at the BPF input via jack normalization. To defeat the BPF signal at the MIX output jack, turn down the BPF Level. When a signal is inserted to the BPF input, it will not go through the VCF. As before, the BPF signal can be defeated from the MIX output by turning down the BPF level. The BPF output jack is not attenuated by the BPF Level knob.

USING A STEREO MIXER WITH SH5-VCF
By using any Eurorack stereo sub-mixer or matrix-mixer (sold separately) on the front end, you can send that mixer Left/Right signals into the VCF/BPF module inputs. Via the mixer pan controls (if available), you can distribute the incoming signals between the VCF/BPF any way you like.

2 CV MODULATIONS FOR VCF CUTOFF FREQUENCY
Incoming CV signals can be used to modulate VCF Frequency Cutoff. Signals can be up to +/- 10Vpp DC polar or AC bi-polar at the inputs.
Both CV inputs have inverting and non-inverting behavior where zero is at 12:00.
Both CV inputs offer rough V/OCT Keyboard Tracking, positive or negative, typically a Keyboard Voltage 0 to 8v range – but can be any kind of polar or bi-polar signal. The lack of temperature compensation was also respected. So while the resonance can self-oscillate, the v/oct keyboard tracking is about 3 octaves at best.

USING VCAs WITH FILTERS
To get the most out of the filter experience follow your filter with a VCA. Both the VCF/BPF can allow low frequency signal content to pass through according to filter slope when the cutoff frequency is all the way down. A post-filter VCA (sold separately) is recommended to gate the filter when these passing signals are not desired to be heard. Be sure to check out the G-Storm Electro 2xVCA when available.

https://youtu.be/iou5zQzhgOc?si=pzHqQPMtUeaTxjiz

Check my Reverb store for availability while supplies last and other cool modules http://reverb.com/shop/gstormelectro