Korg Forums

[Mezzopiano]

Hi everyone

Recently i posted a new thread about my Kronos2 ribbon, some patches had random pitch fluctuations and some random cutoff issues, so everything pointed out to be caused by a faulty ribbon, so i disconnected it, and everything was solved, for one gig

Yesterday, the filter glitch started to happen again (patch Sad Saw Slow) where the sound randomly started to be very bright, like a "hiss pop", as it were randomly fluctuating

Also, something that may be related (i dont know anymore at this point), my main piano sound is coming from my iPad (Ravenscroft piano) connected by USB B. So when the KRONOS fails, i can always trust the piano sound to not be affected by glitches on my Kronos controls (pitch, vector, ribbon) but the other day, the Kronos randomly transposed (i was using some EP sound, playing "New kid in town" by Eagles) and the issue was not the pitch, nor the vector joystick, nor the ribbon, so by instinct, i switched to the iPad piano sound. It was also transposed, and not by a semitone, maybe 2 whole tones? i cant remember)

I quickly turned off the Kronos and back again, the issue was gone.
What i am trying to say is that i dont trust my Kronos anymore, i have seen a lot of thread about random volume fluctuations, and some ones about random transposition, but it is always 1 semitone. My issue is always random, sometimes is the pitch, sometimes is random glitches in the sound coming (i think) from the cutoff.

My OS version is 3.1.3. I have had a very busy end of year with gigs, but now im 2023 i will try to record a video of the issue happening to see if someone has a clue of what is happening.

I dont have a KRONOS service in my country, so no one here to help me out

[wocongming]

[Pedja]

According to what is written on the website regarding revision 3.1.4:
" Release notes:
Removed the limitation on the number of EX installations/uninstallations ".
No mention of any bug fixes.
It is possible that your OS was damaged.
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[Falcon2e]

I would send some time playing your K with nothing connected to it other than your sustain pedal, maybe you can isolate the problem. I don’t think it’s an OS glitch.
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Kronos2-61..(2) Triton Classic, Nord Stage 2, Previously owned lots of other gear dating back to the 70’s.

[aron]

If you can get some kind of MIDI monitor app for the iPad, run it and see exactly what the Kronos is sending to the iPad. That will tell you a lot.
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Korg Kronos, RD-88, Yamaha VL1, Deep Mind 6, Korg Kross, author of unrealBook for iPad.

[Mezzopiano]

I have updated the system to 3.1.4, i have a gig in 2 days, lets wait and see if something strange happens, yesterday i played a little and no strange thing did happen, but that is no indication of anything

[ronnfigg]

Have you tried re-seating the RAM and any cable/ribbon connectors? If you're gigging with this a lot they may have come loose.
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"To me the synthesizer was always a source of new sounds that musicians could use to expand the range of possibilities for making music."
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[SeedyLee]

I notice you said you have an iPad connected via USB: how do you k ie the iPad application you’re using isn’t sending various continuous control messages back to the Kronos vi USB?

I very much doubt it’s loose RAM, or a software glitch. My bet would be on the iPad sending CCs, or if it is a hardware fault (and it’s affecting multiple controls) then it’s likely to be the ADC chip on the fader board, or perhaps a ground/power issue. What I would suggest trying is using the onboard sequencer to make some recordings without the iPad connected, and if it occurs, see what events the sequencer captures.

The MIDI implementation on the Kronos is insanely complex - more complex than any instrument or software synth I have seen. It can be really easy to get stuck in inexplicable territory that turns out to be something stupidly simple.
_________________
Current Equipment:
Korg Kronos 2 88, Reface CS, Roland JV-1080, TE OP1, Moog Subsequent 37, Korg ARP Odyssey, Allen & Heath Zed 18, Adam F5, MOTU MIDI Express XT, Lexicon MX200 & MPX1, Yamaha QY700, Yamaha AW16G, Tascam DP008ex, Zoom H6, Organelle, Roland J6 & JU06A

Previous: Triton LE 61/Sampling/64MB/4GB SCSI, MS2000BR, Kronos 1 61, Monotribe, NanoKontrol, NanoKeys, Kaossilator II, Casio HT3000, Roland VP-03, Reface DX, Novation Mininova, MPC One

[Mezzopiano]

[Mezzopiano]

Ok the issue has just happened. Im on the middle of a gig and was able to capture it on a MIDI monitor app.

[img]https://ibb.co/8jLd9C7[/img]

This was the filter misbeheaving. I dont know what knob it is, as Knob 5 (User 1) is GENERAL -2. Maybe Ribbon controller? But it is not connected

Soon after that the pitch bend also went rogue


[img]https://ibb.co/g42DMYs[/img]

I wasnt even close to the ribbon

[voip]

It may be a power supply issue, though not necessarily the main power supply. It may be a supply on one of the boards, or a poor interconnect between boards. It really needs a keyboard tech to have a look at it.

.

[SeedyLee]

Thanks for sharing. It’s odd that the values are quantised to 64 and 127 precisely…

If my understanding is correct, the ribbon controller connects to the Joystick Board, KLM-3011. Is this where you have disconnected the controller from? KLM3011 then connects to Digital IO board KLM3006, which uses a H8 microcontroller to digitise the analogue signals and key scan from the keyboard to the motherboard be serial UART. The ribbon controller connects indirectly to the H8 via an analogue signal path.

Even though you have disconnected the ribbon controller, the H8 is still generating a signal.

My guess would be on a bad earth somewhere, or a poor connection. I would carefully check all the cabling between the ribbon, the joystick board and the digital IO board. It is probably worth checking the voltages being supplied by the ATX power supply to the KLM3006 board - it should be receiving both 5VDC and 12VDC. It would also be worth checking the voltage on pin 60 of the H8 microcontroller as this is where the ribbon goes from analogue to digital. Any fluctuating voltages or noise here would be a problem. There’s some simple analogue electronics around there they might also be worth checking for obvious signs of damage or dry solder joints etc. That should help you narrow down the problem.

Hope that helps.

Lee
_________________
Current Equipment:
Korg Kronos 2 88, Reface CS, Roland JV-1080, TE OP1, Moog Subsequent 37, Korg ARP Odyssey, Allen & Heath Zed 18, Adam F5, MOTU MIDI Express XT, Lexicon MX200 & MPX1, Yamaha QY700, Yamaha AW16G, Tascam DP008ex, Zoom H6, Organelle, Roland J6 & JU06A

Previous: Triton LE 61/Sampling/64MB/4GB SCSI, MS2000BR, Kronos 1 61, Monotribe, NanoKontrol, NanoKeys, Kaossilator II, Casio HT3000, Roland VP-03, Reface DX, Novation Mininova, MPC One

[Mezzopiano]