Calibrate Your KORG MS 20
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- čas přidán 6. 07. 2024
- In this video we calibrate our vintage KORG MS-20 using a simple digital multimeter, no disassembly required! Have you ever thought your MS-20 sounded ‘off’, or out of tune? We can fix that for you here in this video! Enjoy!
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Would be great a video of Roland SH-1000. The service manual gave few information how to do a perfect calibration in filter section!
Excellent video.
Thanks so much! Thank you for watching, nice to know someone is out there....
Another great video! This will be so helpful to many ms20 owners as its never easy trying to make sense of service manuals. Really nice clear and precise walkthrough.👍👍👍
Thanks for watching! Let me know if you give calibration a try and how it works out for you. I was amazed how far off the filters were on this one.
nice video! thanks
good stuff to know
Amazing thank you so much
Thanks for watching! Enjoy!
Your videos are amazing. I would love to see some on korg Monopoly soon!!! Thanks for sharing your knowledge ;)
Thanks for watching! If someone would be kind enough to donate a Mono-poly I'll make some videos! ;)
Perfect, thanks!
Thanks, glad this helped you out!
Thanks so much. I don't have an MS-20 but an MS-10 and this is so helpful! While I'm at that - my squarewave is giving me a nasty crackle when I narrow the pulsewidth. Any idea what to look for? It's particularly present in 32". To play a bassline in that setting I have to close the LPF halfway or it will sound awful. I know squarewaves are noisy by nature but this is quite extreme. I suspected a leaky capacitor but with all brand new caps the problem is still there :/
Wizard, I just read your message, I'll have a look at the schematic and get back to you! It might be a noisy transistor, or a passive component.
I think 7-3b should have been 'C-1 produces exactly have the voltage of C-2' as 7-3a is about C-3 and C-4. Of course C-2 a quarter of C-4 is true, but where measuring C1 and C2 here.
I have been trying to get the right and I am struggling. C4 perfectly in tune, C1 perfectly in tune, C2 and C3 are -4 cents out. I have tried adjusting the CV and I get a reading of 8.36, so I can't get up to 8.41 like you do but adjusting all these values does not make C2 or C3 any better - what am I doing wrong?
The circuit diagram has a mistake about the placing of the power regulators they are labelled opposite to what they should be
how you got that meter connected up?
It looks like you have the Mk2 there, would you happen to know if the calibration is the same for both mk1 and mk2 ? Thanks
Yes, as far as I can tell the calibration is the same for the Mk1 and Mk2, if by that you mean the KORG-35 vs. OTA filter versions. In fact, the service manual is describing the KORG-35 version (Mk1) and does not include the schematics for the OTA filter board.
@@telefunkian thanks for the info, I think I'm going to just adjust the filters as the tuning seems pretty good on my unit. I need to get a meter like you used 1st though.
One thing I don't understand. Why are the oscillators tuned first and then the keyboard control voltage? It should be the other way around, because changing the CV voltage affects the tuning.
That is a great question and I'm not sure I have a good answer! As you suggest, most synths are calibrated starting with the keyboard CV first, then the oscillators. Maybe it is easier this way on the Korg due to the exponential CV vs. the more conventional V/octave, I'm not sure. Of course either way we are just adjusting the keyboard and the oscillator _scaling_, as the actual pitch is controlled by the master pitch knob, but still, why start with the oscillators then keyboard, I don't have a great answer.
I believe this should be done as well, first keyboard CV, than pitch. Changing keyboard CV (5) and (6) also changes the 'internal' pitch again...
🎵Calibration time, come on!🎵 (sorry).
Your reference might be lost on less 'vintage' viewers, but I get it! Thanks for watching!
Does the MS-20 mini have internal trim pots to perform this calibration? because my keyboard is about a semitone off through its range and it's basically unusable in its current state.
Yes. Caveat: though Korg claims to have faithfully reproduced the analog circuitry with modern (read surface mount) components, I have no idea if the PCB labelling of the individual components in those reproduced circuits is retained or not. I suspect _not_. Your best hope here is to obtain a service Manual for the Korg mini.
The trimpots for the calibration on the MS-20 Mini are located on the lower left side of the main board if you are looking at the "front" of the board with the knobs. You can also access them through the back of the main board on the lower right side with a thin enough screwdriver (this is a lot easier because you will just have to remove the back panel). According to an image I found on the Gearspace forums: PT1 = Keyboard Tracking, PT2 = VCO1 Tracking, PT3 = VCO1 Pitch, PT4 = VCO2 Tracking, PT5 = VCO2 Pitch - tweak at your own risk!
Is any of this applicable to the MS-20 mini?
This is a description of the calibration of the vintage1978 MS-20, the new 'mini' is calibrated at the factory, although I have heard that the factory calibration is pretty poor.
@@telefunkian I was just curious really. I'm sure the original was calibrated at the factory too, but the passage of time affects everything.
I've not had any tuning problems with the mini's oscillators at all yet, although I've not managed to get the ESP pitch to voltage to work as well as I have seen in demos of the mini, not even if I feed it a pure sine wave. I've seen that both the original and the mini have some trimmers down in the ESP section but I've not managed to find any documentation for calibrating that.
why is the tone so harsh on the ear?