The AJH Synth Sample Hold & Slew is a real powerhouse module that takes up only 12 HP of rack space. It can generate random and pseudo random control voltages, staircase waveforms, deliberate aliasing of audio signals, portamento type effects, adjustable audio range noise and has many other uses too.
It can be switched between Sample & Hold or Track & Hold modes, and the unique “Restrict” control affects the way the hold output changes with respect to the current input level and previously held output level. With the control fully off the unit behaves just like any other S/H, but at fully clockwise the output is restricted to move by only a small amount after each new sample. The output will still have the same range as the input, but will need more hold commands to get there. This versatile Sample and Hold circuit was designed by Tony Allgood, and is built under licence from Oakley Sound.
The Sample Hold & Slew module also includes a very well featured Slew generator, which includes a Gated Slew function. It can be used independently or chained with the S&H module. Slew mode can be switched between Linear or Exponential Slew types. There is a Gate input, so that the Slew on/off can be switched using an External CV (Gated Slew), and also the Slew control logic can be reversed by a toggle switch that doubles as a manual Slew on / off switch . In addition, it has slew up only, slew down only or slew up and down modes, which are selected with a three-way toggle switch. An indicator LED lights when Slew is active
There is also an inbuilt analogue Noise generator, which is normalised to the input of the Sample and Hold section, and there are both regular and clipped Noise outputs – the Clipped Noise is particularly useful with the sample and hold section, as it is weighted to produce higher random voltages. Both Noise outputs are fed through an internal “Noise Colour” control – at centre position it allows the noise through unfiltered, turning the control anti-clockwise introduces low pass filtering of the Noise, and rotating it clockwise introduces high pass filtering.
The Noise source itself is based on an analogue bandgap shunt regulator configured in avalanche mode, and it generates white noise with a gradual roll off above 8kHz. It is a little “grainier” in character than the noise from our MiniMod Glide & Noise module (which uses a reverse biased transistor as a noise source), so is a useful compliment to this module as it does not generate exactly the same sounding Noise
Lastly, it includes a wide range clock generator with a rate LED. The range is from one cycle every thirty seconds to around 2 kHz and the clock output is normalised to the Clock Input of the S&H section. It also has a Clock Out jack so that it can be externally patched to other Eurorack modules.
Power: 55mA @+12v / 40mA @-12v