[sdiy] Modding the MKS-3(7?)0 - Looking for suggestions

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On Saturday 23 June 2007 21:45, dj hohum wrote:
> Recently I've been thinking about modifying the analog paths of some
> of my polysynths. In particular, I'd like to do something with the
> JX-10 as I've had this love hate relationship with it for as long as
> I've had it.
Sorry for the late answer to this thread as i have 2200 unread messages in my 
SDIY folder ;) 

I have a MKS70 and theses days i have been wondering how to make it sound 
more "vintage". I bought it for less than 100USD with a broken solder that 
took me 5mn to fix and i was quite disapointed by the DCO, specially because 
it has so great reviews on harmony-central. Well, nothing juicy, compared to 
a VCO the sound is quite rough and it asks for a lot of processing (tube 
preamp) to make it sounds well. Overall it is certainly a fine synth despite 
some limitations (1LFO !!) and probably a good candidat for modding.

What i was silently wishing:
-some sort of "boost" circuit post filter (X12 !) to make it sound 
fatter/older. There are several simple circuits from the guitar world from 
soft boost to overdrive, need investigations. Some noise will certainly jump 
in the game, so the best thing is to do that before the VCA stage (not sure 
if the Roland chip would allow it).

-on the DCO, is there a possibility to make the DCO less stable !? :)) lol, i 
am not yet very aware of the circuitry around the triple counter chips used 
in the MKS70, but i had crazy ideas like making the central clock jittery. I 
am afraid it wont work so i hope the boost circuit will already bring enough 
fatness..

-A sub-osc on the DCOs. At least this mod should be fairly do-able. Even 1 
subosc would allow massive sound weaponery on that synth.  

-Some waveshapper (prefilter)

-a 12db mode on the filter, i really like 12db filters, i remember on my (now 
sold, regrets) DSS1 Korg, how it was nice to have this mode to make 
beautifull pads..  Others modes like 6 or 18db may be interesting. 
Audio modulation of the cutoff, like someone mentioned, would be nice too.

Amongst the other ideas, adding a third delay line on the choruses, ala 
Solina, but it seems that the new J.Haible Chorus project is going to foster 
that need (at least i hope). 

Some of theses mods may requires an external way to recall the parameters. 
After all what matter is not on board patch storage but control from a 
computer or a MIDI box. I would go for a serial or parallel port solution as 
its easy to handle from software like Puredata.

NR