EML 101 and 100 1 V/Octave Mod PCBs and Kits now available

EML-101/100 1 V/Octave Mod kit installed

By “somewhat popular” demand (having been asked for the schematics “several” times) we have made a PCB and kit available for the circuit we use to add 1V/Octave scaled input to the ElectroComp EML-100 and EML-101 synthesizers.

The EMLs use between 1.2 V/Octave and 1.4 V/Octave (varying from one unit to another) with an offset of between 4.2V and 4.6V. Our board allows you to feed in conventional one volt per octave control voltage from another synth, controller keyboard, sequencer, etc. and scales it up so that the EML’s second-voice oscillators (Oscillators 3 and 4) can track it. Using a sequencer especially opens up amazing possibilities for this already very powerful synth!

Our original version of this circuit just performed the summing and amplification and required the installation of a new external switch to turn the mod on and off. Our new version uses a multiplexer to automatically perform this switching task when a plug is inserted in the CV input jack. This means that it can be completely invisible– no hole needs to be drilled, and the synth functions 100% as original when nothing is plugged in.

The mod can be used on both versions of the EML-101. On the later version that has a “Sequencer” jack, the Sequencer jack becomes the 1V/Octave input, and on the earlier version, another jack can be selected to be the new 1V/Octave input (we use CM3).

We are looking for someone to help us take photos of the installation in an EML-100 in exchange for a free PCB or kit so if you have a 100 and are interested in the mod, please get in touch!

The PCB will come with schematics, bill of materials and detailed installation and tuning instructions with lots of full color photos. The kit will come with all of the above plus all required parts and the jack already partially wired (because this is probably the thing people are most likely to mess up!)

The PCB and kit can be ordered here!

ARP Avatar – Retroaktiv patch bay kit installation and the vintage synth modding controversy

ARP Avatar with Retroaktiv “Modular Patch Bay Kit”

This was a pretty big mod project that Darian finished a few weeks ago on an ARP Avatar, the ARP guitar synth which is mostly just a keyboardless Odyssey with a bunch of guitar-processing junk that no one cares about. That’s just a fact. Anyway, several years ago New England Analog developed this kit to break out a lot of the CV input points and modulation sources of the synth’s architecture to 1/8″ jacks mounted on a single long PCB, and now that New England Analog has closed, a new version of the kit is available from Retroaktiv. Continue reading “ARP Avatar – Retroaktiv patch bay kit installation and the vintage synth modding controversy”