Available as an assembled Module and as a DIY project.
No info about availability.
The Transistor Superladder Variable Slope Filter
The Transistor Superladder or TSL is a voltage controlled transistor ladder filter. Cut-off frequency and resonance are both voltage controlable.
The Superladder VCF module has a variable shape output. It incorporates a feature first seen on the Oakley Orbital prototypes. A single pot allows you to vary the output from one pole low pass to four pole low pass via band pass in the middle.
The Superladder's output is what we call 'Q compensated'. This means that the output volume will not drop significantly when you turn up the resonance pot. This design uses two inbuilt VCAs to achieve voltage controlled resonance without the hassle. At high levels of resonance the Superladder will self-oscillate across most of the audio band and thus can be used as a sinewave voltage controlled oscillator.
The module design uses a discrete transistor core which means it does not clip the signal abruptly but saturates smoothly. This allows the Superladder to sound very different depending on the input signal level. When used with signals below 1.5V peak the Superladder will sound clean and bright. However, take your signal levels above 1.5V peak and it will start to take on a more strident tone particularly at higher levels of resonance. Coupled with the variable slope control, this sensitivity to input level means the Superladder can produce a wonderful array of different tones.
Power (+/-15V) is provided to the board either by standard Oakley 4-way header or Synthesizers.com header. Current consumption is approximately 40mA per rail.
These merchants probably sell this module. Huh?
