Seeking advices on installing an UMR2 and infos on key switch Matrix


Hey guys,

I have been working on an old Boss DR-110 drum machine since quite some time now and after completing tone control mods, I thought about recasing.
But while I’m at it, I would like to add more mods and improvement as (to my surprise), I have become quite fond of this drum machine and I use it more and more, especially live.
Apart from adding individual outputs (with switched jacks, like on the 808), I would like to add some sort of midi capability.
Right now if I want to sync it with the rest of my gear, I have to use it as Master clock through a Korg volca to translate the trigger signal (that I need to multiply on my patterns by 2 to reach 24ppqn).

So I have been thinking about adding an UMR2 to trigger the buttons and to be able to sequence the sound externally (with my LXR for and example, that would be sweet).

I have been reading all the documentation on the UMR2 on the (now dead) forum from Highly liquid but still can’t wrap my head around it.

Does anybody have experience with the UMR2 and Key switch Matrix systems and would be kind to give me some insights on the feasibility of hooking up the UMR2 to the DR-110?

Here is the service manual:

I still can’t figure out if the NAND gate would be an obstacle to the UMR2 and if the key matrix is Active High or Active-Low Select.

Feel free to point me to a simpler or alternative solution of you see fit.

PS: I dismissed the circuitbenders DIN Sync mod kit on this as I don’t want to add another MIDI to Din sync device on top of all the modifications I am planning.

Thanks !

(Image of the switch matrix)


OK…What I will say is not very good for my business but I’m not a very good business man anyway…:sob:
I would NOT recommend the UMR2 at all to externally control the DR110 sounds.
As you can see in the schematics, it is quite easy to pick up the triggers from the CPU and route them to switching jacks.
If you don’t have it installed already, add the I/O board in your LXR and you’re done.
The DR110 sounds need negative trig. but the LXR’s I/O board has the option to set the polarity for each trigger output so it’s no problem.


Hey Modulart. Thanks for the heads up and for your honesty, it sounds maybe a bit far-stretched using the UMR-2 for this. I considered adding the Trigger extension to my LXR and driving the voice board directly, it seems quite easy indeed!
The only trouble i’m running into is the particular triggering needed to make the clap sounds good:
Two triggers are needed, the first one to simulate the flam of people clapping, made of 3-pulse burst separated by 10ms and a second pulse source for the echo/decay later.

So now I’m thinking about a good way to implement these different triggers into the LXR. i still do not know if it would be easier to add an option to the LXR code or to build something hardware to transform a regular 5V pulse to what I need.


Oh and by the way went away and posted my questions in the FB group “Synth DIY” some days and I advertised a bit on your UMR-2, one guy seemed to look for one. I pointed him to your website.