Can this be done?

[T.Rubble]

I have been looking at SUBSTYLER's mod design and the xOxiO mods and can see that a 2nd VCO could be a great mod for a xOxbOx. I have had this different but similarly relatable idea rattling around my brain for a while now and basically lack the aptitude to work out the logistics of making it come to life.
My idea is this: I want to incorporate a complete Monotron Duo with all it's functional knobs, minus the ribbon into my xOx! I'm sure it can be done but don't think I could pull it off without some (or a lot) of help with the design. Also if possible I would love to add in a Monotron Delay, taking Substyler's delay mod cue but with that MS20 filter goodness and adding another additional oscillator.
I would like to hear some thoughts about how this could be done. I imagine having 3 additional de-tunable and independent voices with MS20 style filters running alongside the xOX's freaky sequence's and mixing it all up.
Anyways I've got a lot of thoughts of my own on this but I just wanted to get the ball rolling and throw this out there to all you brilliant minds and see where you all think this could go or what and where the inherent hurdles and obstacles may be.
Ultimately I think it could be a very cost effective and simple way of making an insanely great instrument come together with an as yet greatly under-achieving but very high potential and low cost analogue product in the Korg Monotron series.

[guest]

if the idea is to shoehorn these other devices in
there is plenty of room to do so in the x0x
and running wires around to control things shouldnt be so bad

[T.Rubble]

Exactly, I'm certain it will fit. What I really need is for someone to kind of direct me on the in's and out's per se of how to go about doing the mod. I need to have the xOx sequencing all 3 sections in series. I'm excited about the possibility of having the ability to expand the voicing of the xOxbOx with additional tunable VCO's with each voice section having their own unique character and independent filters.

xOx-has it's cutoff and res pots;
Duo- has its vco1 and 2 pitch pots, x-mod, cutoff and 'peak';
Delay- has lfo rate and intensity, it's vcf cutoff and delay's time and feedback.
At the same time the xOx's ENV MOD, DECAY and ACCENT should be universally applied to all voices.
Maybe someone could tell me if the ENV MOD across all voices is impractical or a bad idea but I think I like the idea of it.

[guest]

it should be possible
if you have schematics for the duo
i could give some pointers

the envmod signal might be a bit wierd
as its biased up for the x0x
but that can be offset

also they probably run at different power rails

[T.Rubble]

Ok great! I'll track those down and pm ya'. I'll post them too, to keep a nice trove of info for anyone else interested in giving it a shot. Thanks.

[phono]

the montron wont track 1v oct tho, so you will need to come up with something in between

[guest]

is it that its not exponential
or that its a different ratio

[T.Rubble]

A very good point. There are workarounds though, since there is a euro-rack module conversion outputting and accepting 1v/oct. Its still possible. What other mods to the Monotrons would be necessary?
There'd be power/tapping xOx. Would that mean the xOx would need to be modded to accommodate but how is the best way to do this? How does the xOxiO kit handle its power drawing or is it even an issue there? I also don't know if a some sort of mixer-ing? circuit would have to be added to the xOx or could this be avoided by running separate outs for each voice? I'd like to address the noiseyness of the Monotrons before adding them as well if possible. I think this would be simple enough though as most of the noise is probably caused by the fact that the outputs are 'headphone' outs at . Upgrading the output signal to +4 with an op-amp will fix that, am I correct?

[T.Rubble]

Got a response finally from Korg, well KorgCanada (nothing from Korg) actually and they say they don't have access to the Duo and Delay schematics even. Anyone know about where to find those.

[guest]

if you have one
open it up and start reversing it

[Altitude]

Are those even out yet?

I have been doing a fair amount of work on the monotribe and it is really quirky design wise. Monotron schematics are available and you might be able to follow those but everything is 0630 SMD so it would be a chore for sure..