2hp Expander for Behringer 1033/1003

Adds Gate Inputs, Low Level Gate Inputs, and Trig Inputs to the Behringer 2500 series envelopes

This is a 2hp expander for the Behringer 1033 and 1003 dual envelope generator, from the 2500 series.

The Behringer clone of the 1003/1033 has a single gate and trigger inputs for both envelopes, unlike the original Arp modules. This 2hp expander gives you additional inputs that allow you to gate and trigger each envelope separately. It is a completely passive interface for patching (i.e. it makes no sound on its own). You will have to solder leads onto the 1003/1033, but thankfully only at the switches where the solder pads are large, so it's very easy to do and does not involve smd soldering. The expander also has a 6 pin header so you can easily detach it from the main module.

You can choose the difference in sensitivity between "low level" and "standard gate" by installing two through hole resistors on the pcb. By using a 3.3k resistor, the difference will be about 1v. As on the original arp 2500 the envelope will be gated if both inputs have signal. The analog OR that makes this possible is already on the PCB, SMD soldered by the fabricator.

The expander has an aluminum panel with black silkscreen. The texture of the aluminum is not 100% the same as the Behringer, but it's close enough for me. I also tried to get the font to be as close to the Behringer module as possible, but it's not exactly the same. To assemble it you need to add thonkiconn jacks. Delivery includes the pcb, panel, and the 6 pin header (not the thonkiconns).

The total depth of the module including the 6pin header is 20mm.

https://www.tindie.com/products/euroutilities/eurorack-2hp-expander-for-behringer-10331003/