The Doepfer A-152 Addressed Track & Hold / Switch is an odd module with a huge variety of potential uses. The A-152 can be a sequential switch, and audio router, a shift register, a sample and hold, and far more. The A-152 is made up of three submodules: a bidirectional multiplexer, a chain of 8 track and holds, and a set of eight digital outputs.

The multiplexer can either act as an 8-in to 1-out switch or a 1-in to 8-out signal router. Using the Address CV input or the clock input, the user can select which inlet/outlet is active.

The digital outputs produce no voltage until their individual stages are addressed, allowing use as a gate sequencer. Interesting patterns and shorter switching sequences can be had by patching into the reset clock input from any of the digital outputs (or even an external source).

The T&H submodule is perhaps the most unique part of the A-152. This section has a single input which is routed to one of eight track and hold outputs. When a particular stage is selected, the input voltage is allowed to pass through that output; as soon as a new stage is selected, the prior output holds at its last received voltage level. This is something like a shift register where the stages do not necessarily progress sequentially, or like a signal router that holds a voltage offset at every outlet except the one currently selected.

And of course, all of these sections are simultaneously controllable via external control voltage for current address as well as a clock input to advance stages. The A-152 is a strong candidate for complex signal routing, sequencing, and vast expanses of experimentation. One of Doepfer's most peculiar module, it never ceases to surprise with the vast array of possibilities it presents.

Features

• Tremendously flexible, open-ended design
• Eight-to-one bidirectional switch
• Eight addressable track and hold circuits with common input
• Eight digital outputs for clock sequencing
• Voltage control and clock inputs for currently selected address/stage
• Reset input for deeper clock control