Korg Forums

[rotallicso]

Hey

I have an issue with a new MS20 mini and it relates to the *magnitude* of Key Thumps and the variability in the field of certain units, I also have a badly calibrated unit in terms of voltages. The two issues may relate to one another.

Now, I know this is a design related artefact, but there is strong evidence to suggest huge variability in the magnitude of this Thump - very prevalent on Key Up

Two experienced, but not impartial testers, have shown very different results to the same test performed meticulously

I *really* need one or two more tests (very very simple) performed to establish if my unit is just one of the 'every other' units which does not get re-tested before despatch.

Perhaps, in helping out with this test you can be better informed as to whether you could benefit from a calibration too, possibly courtesy of Korg.

I've set up a test to illuminate the issue, the test has to be performed to the letter to be useful - i'll post the comparisons later

------ TEST

The clicking is most pronounced on key up
Any test conducted should be holding key down for a second or so then waiting a second or so
Do firstly with VCO1 at maximum and then at minimum in the same take - ensuring that no clipping is present to begin with

The headphone out will come through hotter on a field recorder input, but the same behaviour is present when the test is performed on signal out or phones out after normalisation - ie it’s not significant in terms of highlighting the issue

For simplicity here - i’d ask that it’s conducted through the headphones, or both, but do not tinker with or edit the files - Drop recording level to avoid clipping

File attached - should be very simple/quick/clear - important bits are highlighted - everything is vanilla except sustain / release

---------



...........

i am happy to discuss this, it's not a critique of the design, it's a query about the magnitude of the issue in my particular box (it is excessive and quite different from one other unit, so stats are not great to draw conclusions) but a reply to the test would be most welcome - and could be useful for you too
tia
Cheers


ps - this is one of two - the other one is just about calibration - i provided Korg with the voltages, but they would not comment, but asked me to return for calibration tests - i just want to be able to compare and perhaps understand why the VCA issue is so extreme for me[/img]

[rotallicso]

To whet your appetite for the potential variations ...

Here are the like for like comparisons made on three individual units following the procedure meticulously

The variation in OSC bleed / noise level is down to the impact of the spikes of key-thump influencing the Normalisation in the editor

Even when the bleed levels are used as a comparison level the spike levels of the thump are still wildly different best to worst ...

This is a direct comparison zoomed to show only the Key Up stage of the three tests - with oscillator levels at zero it is still very evident on the waveform when the full tilt osc is included



I won't say which was mine or Korg's own test unit just yet !

[rotallicso]

wow - this forum is *dead*
.
.
anyway - the board was swapped by Korg and they believe the replacement board reduces the thump by half - awaiting its return, smug in the knowledge that I spotted it was a dodgy example
.
so clearly there is variability in production

[michelkeijzers]

Thge forum is far from dead, however, possibly most MS20 users don't recognize the problems.

I don't have an MS20 myself so I cannot say anything about the problem itself.
_________________

Developer of the free PCG file managing application for most Korg workstations: PCG Tools, see https://www.kronoshaven.com/pcgtools/

[discONekt]

I have two minis and can attest that one exhibits the thump quite significantly.
While the other does not produce any key thump.

I'd be curious to know which board they replaced for you and if it did indeed help with the issue?

[rotallicso]

[vinyl_junkie]

Hello every one, I'm new here but a long time user of Korg gear.

Any whom I just saw this and found it very interesting.
I have a MS-20 mini and always wanted to know if the DC thump or what ever it is was normal as I found it quite annoying.

I have conducted your test and have attached the file here.

http://we.tl/J0yEfcfQjU

Cheers

Martin

[rotallicso]

Just had a listen and did a visual comparison too
.
The ball park level is broadly the same
Visually, and audibly, it is clear that the example you posted has a much gentler onset click and possibly a slightly more pronounced key-up clunk
.
My initial board was possibly worse than yours, but there's not much in it - i've heard anecdotal tales of quieter versions, but little proof - i made peace with it when Korg swapped mine out - i was satisfied at least that i did not have a one-off problem board and i'm a happy camper now
.
my issue was not with the clunk, but with the possibility it was uniquely bad, this is not the case - thanks for the audio, i would learn to love it or demo a kit or desktop version to see if they're the same, but they won't be as good value or as eurorack ready or as ripe for hacking (on account of the value)