Vintage Synth Repair

Hey, 

Thanks for knowledgeable replies!

Just to clarify as well, the mini in question works well and is calibrated, ie plays in tune.

I have some experience in restoring and adjusting rhodes, wurlitzers and clavinets, and used to calibrate my old Korgs every now and then.

In terms of disconnecting the MIDI board, however, I dont feel competent enough to start soldering in there. And there's no need to, as the mini works fine!?!

Anyway, you may be right, it would be worth it to get a CV system, the expert sleepers or Motu ones look interesting. I was just curios if anyone had a similar mini-MIDI mod, and knew the functionality. I think it is possible to calibrate the MIDI section separately, and thus have both MIDI and keyboard section in working condition. 

The MIDI on the mini is of course secondary, I just have a slight brain damage that means I get pleasure from restoring old electric instruments, with or without mods... Maybe if Im presented with lots of extra time I'll sit down and solve the riddle. Would have to be next year! 

Happy 2011 everyone!

Thor



--- In vintagesynthrepair@yahoogroups.com, PeWe <ha-pewe@...> wrote:
>
> 
> A offset of a semitone is weird.
> Normally, w/ the Minimmog D there´s a CV offset of a 4th (5 semitones) 
> anyway if triggered over MIDI.
> That´s why 0 volts (lowest key on a Mini) is a F and over MIDI it´s a 
> C,- and that has to be compensated anyway.
> So,- if it´s a semitone only, maybe there´s a trimmer on the circuit 
> board on your MIDI interface which isn´t adjusted right or it´s a 
> malfunction.
> If the octaves in hi and lo ranges are not in tune, that´s the octave 
> and hi scaling of the MOOG.
> Only if you´re sure your Minimoog is prefectly calibrated, you´re able 
> to find out what doesn´t work w/ the MIDI interface.
> 
> B.t.w., I don´t have to play/press a key on the Mini´s keyboard 1st and 
> before I can play w/ MIDI,- and my MPU-101 is a very early (but great) 
> MIDI>CV interface.
> It all depends on how it´s modded inside the Minimoog.
> With my Mini, I can toggle between the always connected MIDI>CV 
> interface and the internal keyboard on the fly,- a toggle switch 
> replaced the [DECAY] ft.-switch connector in the left hand controller 
> unit and there are no offsets at all.
> There are also additional trimmers on a small circuit board inside my 
> Mini compensating tuning/scaling differences across the keyboard vs MIDI>CV.
> It´s all doable ...
> 
> What I wanted to say in my former posts is:
> Before you spend countless hrs. to refurbish a unknown MIDI>CV interface 
> inside your Mini,- throw it out and rewire the connections inside the 
> Mini to make it work as it should.
> Buy or borrow (for testing) a cheap and eventually used single channel 
> MIDI>CV interface which works,- there are DIY solutions or some Kenton, 
> Doepfer, Philip Rees or whatever, and connect it to the jacks the Mini 
> already offers, then see what happens.
> Most of these interfaces compensate the CV offset already and offer a 
> Gate-Out to MOOG Switch Trigger cable connection.
> 
> 
> Am 30.12.2010 14:20, schrieb thorkvande:
> >
> >
> >
> >
> >
> > Hey,
> >
> > Just to clarify; the MIDI kit itself works, although it plays about a 
> > semitone off, and the octaves (ie high and low range) are not in tune.
> >
> > Thor
> >
> >
> >
> >
>