SH5-VCF

Roland SH-5 Dual Filter Adaptation + 4-Channel Mixer

Time to get a little more serious.

SH5-VCF is an all analog Eurorack adaptation of the Roland SH-5 mixer and Dual Filter. There are no filters-on-a-chip here. The SH5-VCF uses all discrete components and quality op-amps to work its special mojo. Like on the original, the Low Pass circuit is comprised of open-collector matched transistor pairs arranged in a diode ladder configuration. 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. 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, but greatly expanded upon using a proprietary voltage controlled feedback path to enable frequency control via external signals. This feature wasn’t available on the original design. The original did not have a buffered output jack for the BPF neither, as the SH5-VCF does. The BPF Level attenuator will affect the main output only.

The MIXER
There are four audio signal inputs, each with its own fader pot and filter routing switch. Each routing switch can send each audio line to either VCF, BPF, or both VCF + BPF.

The 3 CV MODULATIONS – Choose Wisely
Incoming CV signals can be used to modulate any filter frequency cutoff. Signals can be up to +/- 10Vpp DC polar or AC bi-polar at the inputs.
| CV1 | has inverting and non-inverting behavior where zero is at 12:00.
| CV2 | has non-inverting behavior for both filters, and inverting available to VCF only
| KB | is a non-inverting V/OCT Keyboard Tracking control available to both the VCF and BPF, typically a Keyboard Voltage – but can be any kind of polar or bi-polar signal.

To get the most out of the filter experience follow your filter with a VCA. The filters require startup voltages on the low end to avoid audible thump, so there will be sub-frequency audio seepage. A post-filter VCA (sold separately) is recommended to gate the filter. Be sure to check out the G-Storm Electro 2xVCA when available.

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