Highly Liquid Forum facebook twitter google plus rss feed
Old 01-30-2014, 11:20 AM
Sandrow Sandrow is offline
Junior Member
Join Date: Jan 2014
Posts: 2
Default Elka Synthex Pre-series prototype

Hi there,
I have a pre-series ELKA SYNTHEX prototype, and my goal is to install MIDI control on it.

"Normal" Synthex could be upgraded by factory MIDI installation, this concern an Eprom swap with new code, installation of two new memory chips, and little wiring on CPU card.
The original factory retrofit has been cloned with success, and you can find all the info here:

Now, this retrofit can't fit my machine for two simple reasons:
I can't swap Eproms, standard Synthex has two TMS2532JL for source code + 1 TMS2516 for presets, mine has three TMS2516JL for source code and one for presets.
CPU card is slightly different in size and routings than official Synthex schematics

So the only chance i have is to use MIDI to simulate the keyboard keypress signals intercepting the original keyboard signal's paths.
I'm not too interested in use Synthex as master keyboard, it's more interesting for me to drive NOTE ON/OFF by external MIDI sources.

Schematics sketches of the keyboard matrix, original midi retrofit and keyboard card here below.

Attached Images
Reply With Quote
Old 02-04-2014, 05:04 PM
John's Avatar
John John is offline
Join Date: Jan 2009
Posts: 3,007

Hi Sandrow, welcome to the forum.

As far as I can tell, this keyboard does not use a typical matrix circuit as described here:


So therefore, the UMR2 won't be compatible.

A straightforward but inelegant approach might be to use the 5V outputs from an MD24 (when the new version is available) to simulate a keypress at the keyswitch. Of course, you'd need one logic output for each key, so multiple MD24s would be required.
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT. The time now is 05:35 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.