[sdiy] Hohner Electronic Piano

[Gregtronic]

Hey all.  I just got a Hohner International Electronic Piano.  It has  
two sounds which are piano and harpsichord which both sound cool  
especially when you mix them together.  Also it has a nice vibrato  
function which has control over the speed.  Of course the moment i  
got this, my mind starts wandering to cool ways i could mod this.  It  
would be great if i could access the filter(s) to add controls, the  
vibrato so i could adjust depth, and if i could modify the envelope.   
The first two mods would be simpler than the envelope mod.  Because  
the synth uses frequency dividers, there's an envelope for each  
individual note.  But i'm thinking if i could just got a constant  
sustain signal, i could use a volume pedal and have a pretty sweet  
string synth.  That, added with the controls for the filter and vibrato.

Of course, without the schematics i'm pretty much hopelessly lost at  
this point, as i have never even attempted to reverse engineer  
anything, so i'm saving that for my last possible choice.  Does  
anyone happen to know if there are schematics or a service manual  
around for these?  There's not much information on the internet as it  
is about these guys.  Also, are my mods even realistic/possible/worth  
it?  Any help or information anyone has would be greatly appreciated.

Cheers!

-Gregory