PCBs and kits now available for ElectroComp EML-101 and EML-100 V/Octave scaling mod

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belltones
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Joined: Mon Aug 07, 2017 10:52 pm
Real name: Alison
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PCBs and kits now available for ElectroComp EML-101 and EML-100 V/Octave scaling mod

Post by belltones » Wed Aug 07, 2019 6:37 am

Hi folks, so about two years ago I shared a video I had made here, demoing a mod my vintage synth repair workshop (Bell Tone Synth Works) had done to add 1V/octave scale conversion to the upper voice (Oscillators 3 and 4) CV input of the ElectroComp EML-101. The EML-100 and EML-101 have an unusual scale of between 1.2V/oct and 1.4V/oct (varying from unit to unit) with an offset of between +4.2VDC and +4.6VDC.

I am posting about it again in case any of you synthsters might be interested to know that we have just made PCBs and kits of the mod circuit available so that people can perform it on their own EML! The design we now use also has a major improvement: 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% normally when nothing is plugged in.

While Kenton and some other MID/CV boxes may be able to send 1.2 V/Oct, they can't do 1.4 V/Octave or add a sizable DC offset, and also cost a lot more than our mod.

The mod can be used on both versions of the EML-101, and the EML-100. We are also currently looking for a DIY-capable EML-100 owner to take pictures of the mod being installed so we can illustrate our instructions, in exchange for us sending them a free kit or PCB so if that applies/appeals to you please get in touch through our website! (Detailed, illustrated installation instructions for both versions of the EML-101 are already done).

Full details here: http://www.belltonesynthworks.com/blog/ ... available/

Thanks for checking this out!
Alison

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