MIDI for Korg Monopoly = Midipoly

[covariance]

Originally Posted by Don Solaris

Hmmm strange. VCA in my MonoPoly is basically noiseless.

(though mine is completely recapped and full calibrated to orig factory specs)

Which revision you have?

New version recapped here.
Noise is unnoticeable until you cut off the oscillator or at heavy low pass filtering. After compressing the noise rise up.
VCA is a simple transistor pair. Incoming signal level is 20 mV and there are two VCA stages in serial, that doubles up the noise.
Would be better with one stage and VCA IC like SSM2164.

[synthesizitis]

Originally Posted by covariance

Midipoly is a new retrofit tuning kit for the Korg Monopoly.
Actually a CPU replacement with some nice controlling add-ons.
Highlights:
- No-drilling installation
- MIDI note In and Out
- Pitch bend controlling with MIDI
- Cutoff controlling with MIDI
- Portamento On/Off controlling with MIDI (emulating those 303-ish slides!)
- Arpeggio synced to MIDI
- Triggering the 4 oscillators independetly with MIDI velocity

Release in October.
If you like to check Midipoly live:
Cema & Synus0006 live act on 6th of October, Budapest with special guests Mike Parker and Stanislav Tolkachev.
PANEL TRAX RECORDS 3-year anniversary with special guests: MIKE PARKER /USA/ and STANISLAV TOLKACHEV /UKR/ | Facebook

Awesome stuff

The Minerva has been a joy.
Guess next is Polysix?

[covariance]

Originally Posted by synthesizitis

Awesome stuff

The Minerva has been a joy.
Guess next is Polysix?

There are several Polysix MIDI available.
CHD on the cheap side and the upcoming Kiwisix on the high-end.
What would be the clever way to enter the market?
I know there are (still) many many P6s in use and many of them still not midified.
That's a good starting point.
I must say there are exciting projects on my wishlist so hard to decide which one to work on.

[synthesizitis]

Originally Posted by covariance

There are several Polysix MIDI available.
CHD on the cheap side and the upcoming Kiwisix on the high-end.
What would be the clever way to enter the market?
I know there are (still) many many P6s in use and many of them still not midified.
That's a good starting point.
I must say there are exciting projects on my wishlist so hard to decide which one to work on.

Kiwisix?
Wow

Thanks for that Laszlo.
Sadly had to part with my Korg M/P

Maybe its time to get another one

[microwave]

I'll be keeping an eye on this, I always wanted a midi in for my Monopoly.

[xanderbeanz]

Yeah me too, I currently have a little Phil ree's CV converter, and whilst it's a clever and highly configurable kit for the time it was made, it only has two outputs, meaning I can control pitch and trigger, OR filter cutoff and trigger (with pitch controlled via the keys) but not all 3 at the same time.

Not an incredible hardship, as the midi is being mainly used for static basslines or unpitched percussion, so one of the above configurations always works, and i play alot of parts in live as audio, but it would be nice to have a mono/poly that responds to CC's to experiment with.

And that sample and hold will be marvellous

[Oli]

Very cool, and affordable. Nice. I don't have M/P, but will probably install this for my friend's unit.

[Rob Ocelot]

Originally Posted by covariance

There are several Polysix MIDI available.
CHD on the cheap side and the upcoming Kiwisix on the high-end.
What would be the clever way to enter the market?
I know there are (still) many many P6s in use and many of them still not midified.
That's a good starting point.
I must say there are exciting projects on my wishlist so hard to decide which one to work on.

The P6 upgrade market is starting to get crowded. I'd probably stay away from the P6 for a lot of reasons, chief one being that the majority have battery damage or repaired damage. Murray's (Kiwitech) solution is to replace the KLM-367 board entirely which I'm sure isn't going to make the Kiwisix a cheap upgrade.

One alternative might be the Poly-61, the majority of which are the MIDI-less earlier version. A Poly-61 with CC control over synth paramaters and an extra LFO would be a nice thing indeed, and a worthy equivalent to Kiwi's JX-3p expansion.

[jessem]

Any update on this project?

[microwave]

yes, please let us know how its getting on, I for sure would buy this retrofit.

[Septik]

I would also be interested in this for 150

[saw wave analog]

I'm just gonna keep asking for a kit for the Source until you tell me to **** off :D that synth is absolutely begging for it.

I've done several Minerva installs, shipping is always fast, and they work great. Covariance is the MIDI Jeezus :D

[xanderbeanz]

Can you retrofit this?



Just kidding, that was my b'day cake

[Ned Bouhalassa]

Wow! Lucky you!!

[covariance]

It's getting more and more exciting as release of Midipoly comes.
Development is 95% done, production starts in January.

I like to share a simple modification that fastens attack of the VCA envelope.
Shortcutting R23 on KLM 355 (filter-vca-env) board roughly doubles attack speed. See the attached oscillogram.
Of course same modification can be applied to the filter envelope (R16).
I measured about 0.4 msec attack time.
I installed a little trimmer in my Monopoly so anything between super fast and original factory speed can be achived.

Another improvement is directly related to the Midipoly mod.
It is surprisingly giving a much better keyboard action compared to the factory processor. No dead keys, no retriggering notes.
Hope you will enjoy them, too.

[covariance]

In production, shipping starts on 15th of January.
Price: 139 EUR + 10 EUR shipping

Summary:

"Midipoly s a MIDI retrofit for the Korg Mono/Poly synthesizer. It is installed internally but with a minimum harm to the original system hence can be called non-destructive.
The Midipoly board is a direct replacement of the factory Korg microprocessor which is in socket so installation is easy.
The MIDI sockets are mounted on a plate which is installed as a replacement of the power plate.
The new power plate is fitted with modern IEC type inlet and there is also room for the original model number plate.
The voice generation and the tonal character of the synthesizer are not affected by adding Midipoly.
The firmware can be upgraded via MIDI as SysEx data.

What the retofit adds:
- Key notes are sent and received as MIDI on the selected MIDI channel
- VCOs can be triggered individually by velocity
- Notes generated by the arpeggiator are also sent as MIDI
- Received Pitch Bend MIDI data alter pitch bend
- Received Modulation CC MIDI messages alter filter cutoff
- Received Portamento Time CC MIDI messages switch portamento on/off
- A new sample and hold modulation can be routed
- Keyboard action is significantly improved
- the EFFECTS button now does not reset the key assign mode to unison
- Arpeggio can be synced to MIDI clock"

[jessem]

Can you still trigger the arp via external cv?

[xanderbeanz]

Yay my Sample and hold made it I'm currently rethinking my career choice so won't have alot of spare money for a while, but I'll get one as soon as my situation changes.

[Hallu]

Please do the Prophet 600 next. If there was ever a synth that needed an update, its the P600!!!!

[covariance]

Originally Posted by jessem

Can you still trigger the arp via external cv?

Yes. Whole in/out section works, all triggerings and cvs. Midipoly even can act as a MIDI/CV interface with V/Oct scale.

[covariance]

Originally Posted by Hallu

Please do the Prophet 600 next. If there was ever a synth that needed an update, its the P600!!!!

Fortunately it is under development by Jeff.
PROPHET 600 SPIRIT

[dougt]

How is the keyboard action improved? Are you replacing the whole rubber dome/carbon contact mechanism?

[jessem]

Originally Posted by covariance

Yes. Whole in/out section works, all triggerings and cvs. Midipoly even can act as a MIDI/CV interface with V/Oct scale.

Wow great. I'm in!

[Rob Ocelot]

Originally Posted by dougt

How is the keyboard action improved? Are you replacing the whole rubber dome/carbon contact mechanism?

I think he's changed how the keyboard controller polls the keyboard mechanism. The Mono/Poly has a little lag in that regard. (I encountered a similar increase in keyboard responsiveness with the MIDI upgrade for the Pro-One from MTG)

Unfortunately the Mono/Poly uses the same rubber dome/carbon contact system as the Polysix and no one has a good replacement for that (yet). I've had good success repairing a Polysix keyboard with silver conductive ink used to repair car defrosters -- coat the rubber contact with the ink, let it dry and then pull the dried disk of ink off. There will be enough residual silver particles for the contact to work. If you leave the dried ink on there it'll eventually flake off and short the contact.

edit: http://www.amazon.com/Permatex-15067.../dp/B000HBI9YQ <--- this is the stuff

[Hallu]

Originally Posted by covariance

Fortunately it is under development by Jeff.
PROPHET 600 SPIRIT

I'm really rooting for this coming together, but he's never done something like this before! You have! Make dreamz come tru

[minisystem]

Originally Posted by Hallu

I'm really rooting for this coming together, but he's never done something like this before! You have! Make dreamz come tru

I tried to coax Laszlo into doing it a couple of years ago and he said it wasn't on his list so eventually I decided to have a crack at it myself. Rest assured it is getting done, just taking longer than if someone like Laszlo was doing it. I even have a couple of proper software engineers helping me out.

Sadly, I sold my Monopoly a few years ago [regret]. I do have the Io installed in my JP4, which is awesome!

[covariance]

Originally Posted by dougt

How is the keyboard action improved? Are you replacing the whole rubber dome/carbon contact mechanism?

It is just the software and maybe the new processor.
The new processor is about 8-10 times faster than the original.
This involves faster response. Also sophisticated anti-prell algoritm is used.
The really surprising thing is the feel of the keyboard.
With the original processor a few keys act very badly on my MP (the rubber contact was not refurbished very long time ago).
With the Midipoly feels almost like new. I guess there is a huge difference between input port circuit of the old processor and the new one.
Probably the new one has better input load characteristics.
Remember those 30-year old original chips used obsolete NMOS technology.

[kebu]

Great news! Definitely considering getting Minerva and Midipoly retrofits in the near future. Also, a Korg Poly-61 retrofit would be much appreciated! That synth has some serious sound but is crippled by the simplified interface.

[xanderbeanz]

My Midi/Poly is winging it's way over to the UK right now, i'll report back here when i get it fitted!

[frico]

Originally Posted by saw wave analog

I'm just gonna keep asking for a kit for the Source until you tell me to **** off :D that synth is absolutely begging for it.

Totally! Would buy one instantly!