Korg MS-10 Mono Synth

[goom]

I posted this question in another forum before I saw "Instrument Forum." Didn't mean to double post.

I'm getting frustrated with tuning my Korg MS-10, trying to get the low and high notes in tune with each other. When I set the top, then set the bottom, the top detunes. I keep going back and forth.

Any tips? Thanks.

[Dave Peck]

It sounds like the oscs kybd tracking needs calibrating. It's not hard to do. But it's really hard to explain how to do it in a forum post. Best if you can get someone to show you how to do it.

DP

[goom]

If anyone would like to try to explain "oscs kybd tracking" adjustment on my MS-10, I'd appreciate it. Thanks.

[Cojo]

Hi.

Are you playing it via midi? If you are then it could be that you have selected V/Octave instead of Hz/V. I'm pretty sure the ms 10 is using the Hz/V scaling.

/Cojo

[goom]

No, I'm not playing it MIDI.

[Cojo]

Originally Posted by goom

If anyone would like to try to explain "oscs kybd tracking" adjustment on my MS-10, I'd appreciate it. Thanks.

When you press a key on a voltage controlled keyboard you get a voltage. This voltage is increasing by 1 for every octave if you have a synth with V/Oct scale. If you have a synth with Hz/V the voltage will dubble for every octave.

In your case this probably means that when you tune one note on your synth, the octave below should be half the voltage. You have to find the service manual to find the right pot to tune.

EDIT: Actually when I think of it I think I've read that the actual keyboard on some synths (or all) is reversed. IOW the volt goes from hi to low. But that's another story.

[Dave Peck]

The most sure way to do this (other than taking it to a service center, which is sort of a waste of money for this task) is to get a service manual, which will describe it in detail. I found a link for manuals :

http://www.musicparts.com/products.asp?Company=Korg

But in general:

If your synth has multiple oscs, only calibrate one at a time - keep the other one turned all the way down.

The oscillator tracking adjustment on analog synths is calibrated using one or two trim pots located somewhere around the oscillators (trim pots are miniature rotary potentiometers that are turned with a small screwdriver-type tool). These trim pots are sometimes accessable from the outside of the unit, sometimes on the back, sometimes on the control panel, sometimes concealed under little plastic caps. And sometimes you have to open the case to find them.

The easiest way to calibrate an osc by ear (without trying to use frequency counters and scopes etc.) is to use a second synth to generate a steady tone and tune your MS-10 to the second synth. Now play an octave up or an octave down on the MS-10 while the second synth continues to drone on the same pitch and notice how far off the tuning is. Keep adjusting the calibration trim pot AND KEEP RETUNING THE SYNTH (because these controls interact) and keep playing the matching note, then an octave up and / or down until the tuning is right at all octaves. It takes patience and some careful listening.

Now the tricky part - some synths also hve a LINEARITY calibration control. This means that the tuning can be calibrated so that one octave up and down sound OK but other notes may still be out of cal. If your synth has a linearity control it may be best to let a qualified tech do the job. If it only has one overall calibration control per osc it's pretty easy to do it yourself.

Also - turn on both synths and let them both warm up for at least half an hour before you start the job so the tunings are not still drifting by themselves while you're trying to do the calibration.

Hope this helps.

DP

[MKS-7]

Burns my ass when people sell old manuals...

tutt

http://www.lazyblueoctopus.com/korg_ms10_service.zip

grab the service manual from this site. This is not mine, but it's a free copy for you.

Each time I'm stuck and cannot find the manuals or service documents and I have to resort to buying them I've scaned them and posted them somewhere. It's quite interesting to see my scans (MKS-30, etc) floating around in cyberspace and it does my heart good to know that it's out there.

I've got an MS-10 being shipped to me right now... so if you can figger out how to do this - please post your methods, and trials and tribulations

Cheers
steve

[esaias]

The calib / scaling trim pots can be found under those little rubber covers on the front panel of MS-10, check the manual how to adjust them.

-Tomi