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AM 8005 Module - Roland SH-5 Filter Cube
Overview This is
the centre section from the unusual and rare Roland SH-5 analog mono synthesizer from 1976. The AM 8005 Filter Cube has:
- A 4-input audio mixer with filter selection
- Ring Modulation
- White and Pink Noise
- Low pass filter
- High pass filter
- Band Pass filter mode using the HPF and LPF
- Dedicated Band Pass filter
- LED indication of signal levels
The SH-5 synthesizer has been used by many famous musicians inclucing the Ozric Tentacles. Technically its a tour de force with 4 filter combinations (hence
me calling the clone a Filter Cube) and a Low Pass 24dB diiode ladder - perhaps similar to the EMS VCS?! Amywhay its a very cool design to replicate and use...
Original Circuit
The original design by Roland is based around a 4 pole low pass diode filter, very similar to the one used in the System 100, and using diodes rather than transistors to avoid copyright problems with the classic Moog design. But that is just a starting point, there is a 2 pole High Pass Filter which can be used inconjucntion with the diode LPF to create Band Pass filter responses. Then there is a dedicated Band Pass filter with resonance, AND a ring modulator based on the MC1496 chip and a white and pink noise generator..That is alot of piower, coupled with a mixer which has both level and filter selection.
AM8005 Module I have simplified the SH-5 design just a little, by having 4 audio input sliders rather than five - but the rest of the design has been replicated completely, with just a few modern Op Amps thrown in to
improve the sound. There are three PCB's
- Pot PCB holds the 4 sliders and 5 switches
- VCF PCB has the low and high pass filters
- BP PCB has the Band Pass filter , Ring Modulator and Noise Source
The module has the following front panel controls:
Signal Input Levels (x4) - two are pre-wired to RIng Modulator and Noise Four 3-way switches to route these signals to VCF, BP or both 3-way switch for White, Pink or no noise 3-way switch for VCF filter mode - HP, LP, BP Frequency Cutoff for the VCF Resonance for the VCF Keyboard CV level for the VCF VCF Modulation CV level for the VCF Frequency, Level and Resonance for the BPF
There are five 3.5mm jack sockets mounted at the base of the panel, these are:
Signal Inputs (x2) CV Inputs (x1) Signal Output
Front Panel The front panel is a 6" wide FracRac with Alpha potentiometers and Davies 1910 style knobs.
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