Hello,

hubertalain(at)hotmail.com wrote:
> Hi!
> I've just recently bought (again) a Mono/poly. I am ready to
> share the joy of owning this puppy again... Thanks.
Welcome to the group, Hubert! Congratulations to your regained MonoPoly :-)

Florian

I know one sure way to tell is to listen carefully to the white noise coming out
of your MP. If it's digital there will be a clearly audible looping pattern
(repeating about every second or so). If it's analog, such a pattern will not be
present at all. That's the main reason why Korg decided to replace the dreaded
MM5837 digital chip by a conventional "open leg transistor" circuit I guess.

My MP4 has serial no:374560 and it has analog noise. I think that Korg made the
revisions early on during production, but I can't tell starting at what serial
number.

--- In korg_mono-poly@yahoogroups.com, "intellijel" <danjel@...> wrote:
>
> My MP is serial no: 371112
>
> Is there any way of knowing based on serial no. if I have the updated
> version of the MP with analog white noise circuitry?
>

Thanks Florian, and hello ALL! Actually my first name is Alain. (had to put them
in reverse in my email address because it was already taken).

From what I have read so far, you seem to be THE reference when it comes to the
MP4. Thanks to you, I've already solved a little issue with my DR-110 triggering
the Arpeggiator with a little lag.
Built myself a little "gate to s-trigger" adaptor quite easily, and everything
is in perfect sync now! Thanks again!

Alain.


--- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@...> wrote:
>
> Hello,
>
> hubertalain(at)hotmail.com wrote:
> > Hi!
> > I've just recently bought (again) a Mono/poly. I am ready to
> > share the joy of owning this puppy again... Thanks.
> Welcome to the group, Hubert! Congratulations to your regained MonoPoly :-)
>
> Florian
>

Hello Roby

  > Hello, I've just purchased a KORG Mono-Poly and I want to
  > be a member of your group, thanks.
Congratulations to your new MonoPoly. Welcome to the group.

Florian

Hi,

I had a look at the member count of the group (we are 360) and thought
about what part of the total made Monopoly's this might cover. Does
anyone know how many of them were made?

Florian

Hello Florian,
thanks for your welcome!

--- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@...> wrote:
>
> Hello Roby
>
>  > Hello, I've just purchased a KORG Mono-Poly and I want to
>  > be a member of your group, thanks.
> Congratulations to your new MonoPoly. Welcome to the group.
>
> Florian
>

Hi Florian,
on SynthMuseum the say 10000...

Roby

--- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@...> wrote:
>
> Hi,
>
> I had a look at the member count of the group (we are 360) and thought
> about what part of the total made Monopoly's this might cover. Does
> anyone know how many of them were made?
>
> Florian
>

10000 according to synth museum.

--- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@...> wrote:
>
> Hi,
>
> I had a look at the member count of the group (we are 360) and thought
> about what part of the total made Monopoly's this might cover. Does
> anyone know how many of them were made?
>
> Florian
>

Hi Roberto

> on SynthMuseum the say 10000...
Thanks! That is much to my opinion

Then we can expect to become one of the largest groups at yahoo :-)))

Florian

I've just finished re-calibrating my MP4 from top to bottom. Took me 2 hours.
And in the course of doing so, I realized the importance of certain points.
First, there are some mistakes in the service manual. Not really mistakes, but
more misunderstandings. The whole manual, and the calibration section, is based
on the assumption that an old version of the MP4 is to be serviced.

However my MP4, as well as a LOT of others, is a newer version. So there are a
few extra steps to take while reading the service manual.
But how can you tell if you have an older or newer version ?
Simple, when opening your MP4, if you see a small circuit board on the left
marked KLM327 then you have an old version. On the newer version, that board is
missing entirely.

So for the new version on the KLM355 board, first there is no more VR11 filter
keyboard tracking adjustment. That VR11 is now part of the final VCA adjustments
instead.
Second, when calibrating the offset of each VCO, the wire color reference for
connecting the DVM is completely different. But a correspondence chart is
provided at the end of the manual.
But here they are for quicker access:

OLD         NEW
VCO1 Red    Pink
VCO2 Yellow White
VCO3 Blue   Purple
VCO4 Gray   Green

Also, the trim pots correspondence for the offset adjust is not indicated. So
here it is:

VCO1 -> VR2
VCO2 -> VR1
VCO3 -> VR4
VCO4 -> VR3

Another extremely critical point, is that you have to FIRST calibrate the
voltages on the PSU. Then, calibrate the keyboard CV generation by adjusting the
Key Assigner KLM356 to very precise values (a high precision DVM is essential
here).
Don't start the VCO calibration unless you have confirmed that the assigner is
generating EXACTLY 1 volt per octave, as described in the calibrating procedure.
Otherwise you'll have a very hard time getting things right.

Personally, I prefer to use a digital frequency meter instead of a tuner for the
VCO calibration, and a keyboard frequency reference chart. Numbers don't lie.
Also, it makes it easier to compare octaves.

The end result is not absolute perfection, after all this is not a digital
machine. But I've managed to get the tuning on each VCO to within +/- .1 hz over
the 6 octave range, which is more than acceptable. But it takes methodical work
and patience, going back on previous trim pots several times to confirm their
value didn't change.

So a well spent 2 hours, with an end result beyond my expectations.
Before I calibrated it, my MP4 showed a +/- 5.5 hz difference on all VCOs across
the whole 6 octave range, and the up-normal-down transpose switch showed a +/-
6.2 hz difference ! It didn't sound good.

Hope this can be of some help for those courageous enough (and well equipped
enough, a 4 digit DVM is essential) to undergo this precise procedure. Otherwise
you'd better leave this kind of job to a professional, or end-up with a badly
out-of-tune MP4. You've been warned.

Alain.

Just a short (late) reply to tell everyone that the transfo used in most MP4 is
running quite hot after a an hour or more of use. It is the result of Korg
putting a 1.2 amp tranfo in a synth that consumes... 1.2 amps! So that part is
working in the proximity of its maximum tolerance, and thus dissipates about 30
watts of heat. But that transfo is of high quality and should be able to handle
that kind of heat easily. So I wouldn't worry about that. But no part is
infallible and it could still fail.

Alain.


--- In korg_mono-poly@yahoogroups.com, "plus_321" <plus_321@...> wrote:
>
> Hello.
>
> Just a few moments ago I was playing some music and all of a sudden my
mono/poly stopped working.  I tried to flip the switch and nothing happens; no
lights or sound.  (I didn't see or smell smoke)
>
> I opened it up and the fuses are all fine, but the transformer was so hot that
I couldn't keep my finger on it for more than a moment (even now, 15 minutes
later it is still very warm).
> I used the service manual and checked on board 356 for voltages and none of
them registered(5, 15, or -15).
>
> I'm not sure what to do now.  I'm guessing the transformer died, but how can I
know for sure?  What would cause the transformer to just go out like that?  If
it is the transformer, does anyone here have a spare or know where to find one?
>
> Thanks,
> Chase
>

Hi Alain

do you know my instructions on this:
http://fa.utfs.org/diy/korg_monopoly/vco_adjustment.html ?


> Another extremely critical point, is that you have to FIRST calibrate the
voltages on the PSU. Then, calibrate the keyboard CV generation by adjusting the
Key Assigner KLM356 to very precise values (a high precision DVM is essential
here).
> Don't start the VCO calibration unless you have confirmed that the assigner is
generating EXACTLY 1 volt per octave, as described in the calibrating procedure.
Otherwise you'll have a very hard time getting things right.
Very good point! I'll add it to my instructions

Florian

Hello all,

on matrixsynth there was today a link to a quite good monopoly demo:

http://www.youtube.com/watch?v=sBvSBIyb9AA

Is the person who did this on the list?

Florian

Hello Florian,

Yes, I was aware of your page on this. And thank you for adding my humble
contribution to it. I was about to write you a note about this possibly missing
info.

Although since I use a frequency meter, the service manual from Korg was clear
enough for me.
I just use A4 and A1, instead of A#4 and A#1. (easier numbers to work with:
440hz, 55hz, 3520hz)

My own procedure is quite simple, and follows a path similar to the Korg manual.
And for those of you who would rather use a frequency meter than a tuner, here
it is in 8 easy steps (well 32 to be exact):

Transpose switch to NORMAL. (A voltage of exactly +5.250 V must be confirmed at
the right side of R8 in the KLM356 CV1 output before continuing).

1-Octave switch to 16'
2-Play A4, adjust vr102 to read 440hz
3-Play A1, adjust vr103 to read 55hz
4-Repeat steps 2 and 3 until values displayed are EXACT.

5-Octave switch to 2'
6-Play A1, adjust vr101 to read 440hz
7-Play A4, adjust vr104 to read 3520hz
8-Repeat steps 6 and 7 until values displayed are EXACT.

Repeat steps 1 to 8 for VCO 2-4 with their corresponding VRs.

You're done.

Note: you can tolerate a +/- 0.2 hz value fluctuation to account for analog
drift.

Alain.



--- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@...> wrote:
>
> Hi Alain
>
> do you know my instructions on this:
> http://fa.utfs.org/diy/korg_monopoly/vco_adjustment.html ?
>
>
> > Another extremely critical point, is that you have to FIRST calibrate the
voltages on the PSU. Then, calibrate the keyboard CV generation by adjusting the
Key Assigner KLM356 to very precise values (a high precision DVM is essential
here).
> > Don't start the VCO calibration unless you have confirmed that the assigner
is generating EXACTLY 1 volt per octave, as described in the calibrating
procedure. Otherwise you'll have a very hard time getting things right.
> Very good point! I'll add it to my instructions
>
> Florian
>

Thanks for the link Florian! Very good demo indeed.


--- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@...> wrote:
>
> Hello all,
>
> on matrixsynth there was today a link to a quite good monopoly demo:
>
> http://www.youtube.com/watch?v=sBvSBIyb9AA
>
> Is the person who did this on the list?
>
> Florian
>

Hello Johan,

welcome to the group!

Comment from new user:
  > hello. i would like to do some modifications on my mp and come here
  > for help...

Let us know what you want to modify.

Florian

Yes Johan, welcome!

I've already done a simple mod on mine, to convert arpeggiator trigger input
from s-trigger to pulse.
I also plan to add a sample-and-hold with the clock source as either MG1 or
MG2...

Tell us what you want to mod on your MP!

Alain.


--- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@...> wrote:
>
> Hello Johan,
>
> welcome to the group!
>
> Comment from new user:
>  > hello. i would like to do some modifications on my mp and come here
>  > for help...
>
> Let us know what you want to modify.
>
> Florian
>

Hi everyone! Thanks for the welcome! :)

Well I've been thinking of doing these mods:

VCO->Cutoff FM
VCO->VCA FM
VCO1->VCO(x) FM
LFO speeds increase by adding caps
Audio in -> VCF/VCA
Suboscillators via divide circuit to every square

Oh, and also adding midi, either via Mungo Enterprises Midi Retrofit or this one
: http://www.chd-el.cz/index.php?id=409

I consider myself a beginner in synthmodding, have done a couple on the korg
poly800 (moog slayer, 12/24db filterswitch, fm800 and so on) and siel exp80
(similar architecture as poly800). Also working on fitting the Mungo Enterprises
midikit in a Juno6 atm.



--- In korg_mono-poly@yahoogroups.com, "Alain" <hubertalain@...> wrote:
>
> Yes Johan, welcome!
>
> I've already done a simple mod on mine, to convert arpeggiator trigger input
from s-trigger to pulse.
> I also plan to add a sample-and-hold with the clock source as either MG1 or
MG2...
>
> Tell us what you want to mod on your MP!
>
> Alain.
>
>
> --- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@> wrote:
> >
> > Hello Johan,
> >
> > welcome to the group!
> >
> > Comment from new user:
> >  > hello. i would like to do some modifications on my mp and come here
> >  > for help...
> >
> > Let us know what you want to modify.
> >
> > Florian
> >
>

Good mod choices, Johan.
I like the CHD Elektro MIDI retrofit better than the Mungo. It's a bit more
expensive, but comes already complete and is a more elegant solution for the MP.
But that's only my personal opinion.

A word of advice,if I may. When dealing with mods that concern the VCOs, extra
care must be taken, as those SSM2033 are close to impossible to find as
replacement chips, if ever a mod destroys one (or more) of them.

For this reason, I'd suggest starting with the filter mods. If ever you
inadvertently destroy the SSM2044, there are plenty available (and inexpensive)
on Ebay to replace it. Moreover, it is in a DIP socket for easy removal. The
SSM2033 are also in a socket, but have their Tempco resistors glued on them and
soldered to the main pcb.

The LFO speed increase is entirely feasible, but also be aware that doing so to
MG2 might not trigger the arpeggiator correctly passed a certain speed (cpu
interrupt timing limitation).

Sub-osc via divide is a great idea to get a little more "meat" out of the low
end.

Do you have any schematics to start with, or are you going to engineer them from
scratch ?

Alain.




--- In korg_mono-poly@yahoogroups.com, "JohanI" <johan.inkinen@...> wrote:
>
> Hi everyone! Thanks for the welcome! :)
>
> Well I've been thinking of doing these mods:
>
> VCO->Cutoff FM
> VCO->VCA FM
> VCO1->VCO(x) FM
> LFO speeds increase by adding caps
> Audio in -> VCF/VCA
> Suboscillators via divide circuit to every square
>
> Oh, and also adding midi, either via Mungo Enterprises Midi Retrofit or this
one : http://www.chd-el.cz/index.php?id=409
>
> I consider myself a beginner in synthmodding, have done a couple on the korg
poly800 (moog slayer, 12/24db filterswitch, fm800 and so on) and siel exp80
(similar architecture as poly800). Also working on fitting the Mungo Enterprises
midikit in a Juno6 atm.
>
>
>
> --- In korg_mono-poly@yahoogroups.com, "Alain" <hubertalain@> wrote:
> >
> > Yes Johan, welcome!
> >
> > I've already done a simple mod on mine, to convert arpeggiator trigger input
from s-trigger to pulse.
> > I also plan to add a sample-and-hold with the clock source as either MG1 or
MG2...
> >
> > Tell us what you want to mod on your MP!
> >
> > Alain.
> >
> >
> > --- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@> wrote:
> > >
> > > Hello Johan,
> > >
> > > welcome to the group!
> > >
> > > Comment from new user:
> > >  > hello. i would like to do some modifications on my mp and come here
> > >  > for help...
> > >
> > > Let us know what you want to modify.
> > >
> > > Florian
> > >
> >
>

 

Good mod choices, Johan.
I like the CHD Elektro MIDI retrofit better than the Mungo. It's a bit more expensive, but comes already complete and is a more elegant solution for the MP. But that's only my personal opinion.

A word of advice,if I may. When dealing with mods that concern the VCOs, extra care must be taken, as those SSM2033 are close to impossible to find as replacement chips, if ever a mod destroys one (or more) of them.

For this reason, I'd suggest starting with the filter mods. If ever you inadvertently destroy the SSM2044, there are plenty available (and inexpensive) on Ebay to replace it. Moreover, it is in a DIP socket for easy removal. The SSM2033 are also in a socket, but have their Tempco resistors glued on them and soldered to the main pcb.

The LFO speed increase is entirely feasible, but also be aware that doing so to MG2 might not trigger the arpeggiator correctly passed a certain speed (cpu interrupt timing limitation).

Sub-osc via divide is a great idea to get a little more "meat" out of the low end.

Do you have any schematics to start with, or are you going to engineer them from scratch ?

Alain.

--- In korg_mono-poly@yahoogroups.com, "JohanI" <johan.inkinen@...> wrote:
>
> Hi everyone! Thanks for the welcome! :)
>
> Well I've been thinking of doing these mods:
>
> VCO->Cutoff FM
> VCO->VCA FM
> VCO1->VCO(x) FM
> LFO speeds increase by adding caps
> Audio in -> VCF/VCA
> Suboscillators via divide circuit to every square
>
> Oh, and also adding midi, either via Mungo Enterprises Midi Retrofit or this one : http://www.chd-el.cz/index.php?id=409
>
> I consider myself a beginner in synthmodding, have done a couple on the korg poly800 (moog slayer, 12/24db filterswitch, fm800 and so on) and siel exp80 (similar architecture as poly800). Also working on fitting the Mungo Enterprises midikit in a Juno6 atm.
>
>
>
> --- In korg_mono-poly@yahoogroups.com, "Alain" <hubertalain@> wrote:
> >
> > Yes Johan, welcome!
> >
> > I've already done a simple mod on mine, to convert arpeggiator trigger input from s-trigger to pulse.
> > I also plan to add a sample-and-hold with the clock source as either MG1 or MG2...
> >
> > Tell us what you want to mod on your MP!
> >
> > Alain.
> >
> >
> > --- In korg_mono-poly@yahoogroups.com, Florian Anwander <fanwander@> wrote:
> > >
> > > Hello Johan,
> > >
> > > welcome to the group!
> > >
> > > Comment from new user:
> > > > hello. i would like to do some modifications on my mp and come here
> > > > for help...
> > >
> > > Let us know what you want to modify.
> > >
> > > Florian
> > >
> >
>

Hello Sophie.

Well, is it simply the terms used that you don't quite get, like VCO, VCF, FM,
and such ?
Or is it what the result of those mods would be ?
Or maybe a combination of the two ?

Let's take them one by one:

1-VCO -> Cutoff FM

Would take the output of the oscillators, and control the frequency of the
filter cutoff. That would result in FM (audio frequency modulation) of the
filter. The equivalent of turning the cutoff knob really really fast.

2-VCO -> VCA FM

Same principle, but controlling the volume instead of the filter cutoff.
(actually that would be technically called AM, not FM, for amplitude modulation)

3-VCO1 -> VCO(x) FM

Taking the output of oscillator 1 to control the pitch of other oscillators.
Frequency modulating other VCOs. (Like you can already do now with MG1
controlling the pitch but much, much faster)

4-LFO speeds increase by adding caps

Getting faster speeds from MG1 or MG2 by adding, or better yet changing values
of, timing capacitors (or resistors) in the electronic circuits that compose
those LFOs. Which ones ?
Well to know that, you have to have some technical knowledge or background in
electronics.

5- Audio in -> VCF/VCA

Add a connector to allow external signals (other synths, electric guitar,
etc...) to pass through the filter (VCF), or final amp (VCA) for using the MP as
an "effect" box.

6-Suboscillators via divide circuit to every square

Build additional circuits to effectively add sub-oscillators (oscillators
playing one or more octave bellow the source) to each of the square wave output
of the oscillators.


Hope this helps a little...


Alain.



--- In korg_mono-poly@yahoogroups.com, Sophie Caroline Bernhard
<sophiebernhard@...> wrote:
>
> Hi Johan, Alain and all,
>
> I have to admit it, I am a littler lost with modifications
>
> Where could I get some infos to understand better about those
> modifications Johan wants to make?
> Is there a book, a course (a secret potion)?
>
> Many thanks in advance for your time in this
>
> Sophie
>
>
>
> On 11 Feb 2010, at 21:51, "Alain" <hubertalain@...> wrote:
>
> > Good mod choices, Johan.
> > I like the CHD Elektro MIDI retrofit better than the Mungo. It's a
> > bit more expensive, but comes already complete and is a more elegant
> > solution for the MP. But that's only my personal opinion.
> >
> > A word of advice,if I may. When dealing with mods that concern the
> > VCOs, extra care must be taken, as those SSM2033 are close to
> > impossible to find as replacement chips, if ever a mod destroys one
> > (or more) of them.
> >
> > For this reason, I'd suggest starting with the filter mods. If ever
> > you inadvertently destroy the SSM2044, there are plenty available
> > (and inexpensive) on Ebay to replace it. Moreover, it is in a DIP
> > socket for easy removal. The SSM2033 are also in a socket, but have
> > their Tempco resistors glued on them and soldered to the main pcb.
> >
> > The LFO speed increase is entirely feasible, but also be aware that
> > doing so to MG2 might not trigger the arpeggiator correctly passed a
> > certain speed (cpu interrupt timing limitation).
> >
> > Sub-osc via divide is a great idea to get a little more "meat" out
> > of the low end.
> >
> > Do you have any schematics to start with, or are you going to
> > engineer them from scratch ?
> >
> > Alain.
> >
> > --- In korg_mono-poly@yahoogroups.com, "JohanI" <johan.inkinen@>
> > wrote:
> > >
> > > Hi everyone! Thanks for the welcome! :)
> > >
> > > Well I've been thinking of doing these mods:
> > >
> > > VCO->Cutoff FM
> > > VCO->VCA FM
> > > VCO1->VCO(x) FM
> > > LFO speeds increase by adding caps
> > > Audio in -> VCF/VCA
> > > Suboscillators via divide circuit to every square
> > >
> > > Oh, and also adding midi, either via Mungo Enterprises Midi
> > Retrofit or this one : http://www.chd-el.cz/index.php?id=409
> > >
> > > I consider myself a beginner in synthmodding, have done a couple
> > on the korg poly800 (moog slayer, 12/24db filterswitch, fm800 and so
> > on) and siel exp80 (similar architecture as poly800). Also working
> > on fitting the Mungo Enterprises midikit in a Juno6 atm.
> > >
> > >
> > >
> > > --- In korg_mono-poly@yahoogroups.com, "Alain" <hubertalain@> wrote:
> > > >
> > > > Yes Johan, welcome!
> > > >
> > > > I've already done a simple mod on mine, to convert arpeggiator
> > trigger input from s-trigger to pulse.
> > > > I also plan to add a sample-and-hold with the clock source as
> > either MG1 or MG2...
> > > >
> > > > Tell us what you want to mod on your MP!
> > > >
> > > > Alain.
> > > >
> > > >
> > > > --- In korg_mono-poly@yahoogroups.com, Florian Anwander
> > <fanwander@> wrote:
> > > > >
> > > > > Hello Johan,
> > > > >
> > > > > welcome to the group!
> > > > >
> > > > > Comment from new user:
> > > > > > hello. i would like to do some modifications on my mp and
> > come here
> > > > > > for help...
> > > > >
> > > > > Let us know what you want to modify.
> > > > >
> > > > > Florian
> > > > >
> > > >
> > >
> >
> >
>

Hello Alain and Sophie

> 1-VCO -> Cutoff FM
>
> Would take the output of the oscillators, and control the frequency of the
filter cutoff. That would result in FM (audio frequency modulation) of the
filter. The equivalent of turning the cutoff knob really really fast.
You should add: the result are mostly bell like sounds.
There is already something similar: the crossmodulation in the effects
section. But while VCO->VCO crossmodulation cannot be played tonally,
the VCO->VCF modulation can be played tonally.

This is something very recommendable!


> 2-VCO -> VCA FM
>
> Same principle, but controlling the volume instead of the filter cutoff.
(actually that would be technically called AM, not FM, for amplitude modulation)
pay attention! This disables the function of the loudness envelope. if
you want to play AM controlled by note on note off, you would need a
separate VCA before the envelope controolled VCA!

> 3-VCO1 -> VCO(x) FM
>
> Taking the output of oscillator 1 to control the pitch of other oscillators.
Frequency modulating other VCOs. (Like you can already do now with MG1
controlling the pitch but much, much faster)
This is superfluous: Xmod in the effects section is the same.


Florian

that lfo speed mod is also quite useless to make. you can get crazy
speed lfo's on mg-1 bu carefully placing the mg-1 waveform selector
between the two saw waveforms.
and you can route that superfast lfo with the mg1 modwheel to the filter
or to the pitch, and also the effects section uses that particular mg.
no need for a superfast mg-2 imho.

i would only midify the mono/poly with that chd elektro midi kit, and
maybe that s/h waveform thingie, altho i already get a s/h waveform with
my kentron pro solo.
is that vcf>fm mod something that you can not acchieve with that lfo
trick + effects section really?

that subosc mod seems like overkill since you already have 4 oscs. you
can make the sound with 1-3 oscs, and use a the fourth osc an octave
lower than the rest (with triangle or square it works nicely, but if you
use triangle, remember to mix it louder than the other oscs for maximum
effect!) and i usually have to turn down two oscs when recording stuff.
othervise it won't fit the mix properly.

just my thoughts about modding the good old mono/poly.

Hello Michael
> that lfo speed mod is also quite useless to make. you can get crazy
> speed lfo's on mg-1 bu carefully placing the mg-1 waveform selector
> between the two saw waveforms.
> and you can route that superfast lfo with the mg1 modwheel to the filter
> or to the pitch, and also the effects section uses that particular mg.
> no need for a superfast mg-2 imho.
This inbetween setting of the waveforms switch is not superfast (sorry).
It gets at max ~300Hz, but we talk about max ranges up to 7000Hz.
Doepfer introduced this with the MS-404 and many other makers now
implement it to their todays systems. It allows very interesting vowel
like sounds.

> is that vcf>fm mod something that you can not acchieve with that lfo
> trick + effects section really?
Yepp, it is completely different. I definitely recommend it!

Florian

Hi Alain,

and thank you so much for this clarification. I know what an oscillator or a
filter is, but I have to admit that I could do with a bit more knowledge.

In fact, I always wonder as to how to get some more knowledge about synthesis
and haven't found anything suiting my needs yet, really: either one has to look
into books - and sometimes things can be a bit too abstract - or one can attend
courses but apart from the  online Berklee College in the US (that promotes
learning via softwares such as Reason and Absynth) I haven't found anything.

How did you (Alain and all of you reading this) acquire you knowledge about
synthesis, apart from your own trying and tweaking?

Thanks for reading!


--- In korg_mono-poly@yahoogroups.com, "Alain" <hubertalain@...> wrote:
>
> Hello Sophie.
>
> Well, is it simply the terms used that you don't quite get, like VCO, VCF, FM,
and such ?
> Or is it what the result of those mods would be ?
> Or maybe a combination of the two ?
>
> Let's take them one by one:
>
> 1-VCO -> Cutoff FM
>
> Would take the output of the oscillators, and control the frequency of the
filter cutoff. That would result in FM (audio frequency modulation) of the
filter. The equivalent of turning the cutoff knob really really fast.
>
> 2-VCO -> VCA FM
>
> Same principle, but controlling the volume instead of the filter cutoff.
(actually that would be technically called AM, not FM, for amplitude modulation)
>
> 3-VCO1 -> VCO(x) FM
>
> Taking the output of oscillator 1 to control the pitch of other oscillators.
Frequency modulating other VCOs. (Like you can already do now with MG1
controlling the pitch but much, much faster)
>
> 4-LFO speeds increase by adding caps
>
> Getting faster speeds from MG1 or MG2 by adding, or better yet changing values
of, timing capacitors (or resistors) in the electronic circuits that compose
those LFOs. Which ones ?
> Well to know that, you have to have some technical knowledge or background in
electronics.
>
> 5- Audio in -> VCF/VCA
>
> Add a connector to allow external signals (other synths, electric guitar,
etc...) to pass through the filter (VCF), or final amp (VCA) for using the MP as
an "effect" box.
>
> 6-Suboscillators via divide circuit to every square
>
> Build additional circuits to effectively add sub-oscillators (oscillators
playing one or more octave bellow the source) to each of the square wave output
of the oscillators.
>
>
> Hope this helps a little...
>
>
> Alain.
>
>
>
> --- In korg_mono-poly@yahoogroups.com, Sophie Caroline Bernhard
<sophiebernhard@> wrote:
> >
> > Hi Johan, Alain and all,
> >
> > I have to admit it, I am a littler lost with modifications
> >
> > Where could I get some infos to understand better about those
> > modifications Johan wants to make?
> > Is there a book, a course (a secret potion)?
> >
> > Many thanks in advance for your time in this
> >
> > Sophie
> >
> >
> >
> > On 11 Feb 2010, at 21:51, "Alain" <hubertalain@> wrote:
> >
> > > Good mod choices, Johan.
> > > I like the CHD Elektro MIDI retrofit better than the Mungo. It's a
> > > bit more expensive, but comes already complete and is a more elegant
> > > solution for the MP. But that's only my personal opinion.
> > >
> > > A word of advice,if I may. When dealing with mods that concern the
> > > VCOs, extra care must be taken, as those SSM2033 are close to
> > > impossible to find as replacement chips, if ever a mod destroys one
> > > (or more) of them.
> > >
> > > For this reason, I'd suggest starting with the filter mods. If ever
> > > you inadvertently destroy the SSM2044, there are plenty available
> > > (and inexpensive) on Ebay to replace it. Moreover, it is in a DIP
> > > socket for easy removal. The SSM2033 are also in a socket, but have
> > > their Tempco resistors glued on them and soldered to the main pcb.
> > >
> > > The LFO speed increase is entirely feasible, but also be aware that
> > > doing so to MG2 might not trigger the arpeggiator correctly passed a
> > > certain speed (cpu interrupt timing limitation).
> > >
> > > Sub-osc via divide is a great idea to get a little more "meat" out
> > > of the low end.
> > >
> > > Do you have any schematics to start with, or are you going to
> > > engineer them from scratch ?
> > >
> > > Alain.
> > >
> > > --- In korg_mono-poly@yahoogroups.com, "JohanI" <johan.inkinen@>
> > > wrote:
> > > >
> > > > Hi everyone! Thanks for the welcome! :)
> > > >
> > > > Well I've been thinking of doing these mods:
> > > >
> > > > VCO->Cutoff FM
> > > > VCO->VCA FM
> > > > VCO1->VCO(x) FM
> > > > LFO speeds increase by adding caps
> > > > Audio in -> VCF/VCA
> > > > Suboscillators via divide circuit to every square
> > > >
> > > > Oh, and also adding midi, either via Mungo Enterprises Midi
> > > Retrofit or this one : http://www.chd-el.cz/index.php?id=409
> > > >
> > > > I consider myself a beginner in synthmodding, have done a couple
> > > on the korg poly800 (moog slayer, 12/24db filterswitch, fm800 and so
> > > on) and siel exp80 (similar architecture as poly800). Also working
> > > on fitting the Mungo Enterprises midikit in a Juno6 atm.
> > > >
> > > >
> > > >
> > > > --- In korg_mono-poly@yahoogroups.com, "Alain" <hubertalain@> wrote:
> > > > >
> > > > > Yes Johan, welcome!
> > > > >
> > > > > I've already done a simple mod on mine, to convert arpeggiator
> > > trigger input from s-trigger to pulse.
> > > > > I also plan to add a sample-and-hold with the clock source as
> > > either MG1 or MG2...
> > > > >
> > > > > Tell us what you want to mod on your MP!
> > > > >
> > > > > Alain.
> > > > >
> > > > >
> > > > > --- In korg_mono-poly@yahoogroups.com, Florian Anwander
> > > <fanwander@> wrote:
> > > > > >
> > > > > > Hello Johan,
> > > > > >
> > > > > > welcome to the group!
> > > > > >
> > > > > > Comment from new user:
> > > > > > > hello. i would like to do some modifications on my mp and
> > > come here
> > > > > > > for help...
> > > > > >
> > > > > > Let us know what you want to modify.
> > > > > >
> > > > > > Florian
> > > > > >
> > > > >
> > > >
> > >
> > >
> >
>

Hi Sophie,

The "Synth secrets" series on the Sound on Sound website is a very good
start to understanding synthesis

http://www.soundonsound.com/search?url=%2Fsearch&Section=8&Subject=12

A lot of other very good articles there as well.

You could also do worse than download the Nord Modular G2 demo and play
with it, as you will be building your own (software) synths and apply
what you've learned in the Synth Secrets articles.

http://www.nordkeyboards.com/main.asp?tm=Downloads&cldwn=Nord_Modular_G2&osdwn=o\
sw

Then it is just a case of applying that knowledge to the MP, some of the
names are slightly different.

Vale

lakaband_in_uk wrote:
>
> Hi Alain,
>
> and thank you so much for this clarification. I know what an
> oscillator or a filter is, but I have to admit that I could do with a
> bit more knowledge.
>
> In fact, I always wonder as to how to get some more knowledge about
> synthesis and haven't found anything suiting my needs yet, really:
> either one has to look into books - and sometimes things can be a bit
> too abstract - or one can attend courses but apart from the online
> Berklee College in the US (that promotes learning via softwares such
> as Reason and Absynth) I haven't found anything.
>
> How did you (Alain and all of you reading this) acquire you knowledge
> about synthesis, apart from your own trying and tweaking?
>
> Thanks for reading!
>
> --- In korg_mono-poly@yahoogroups.com
> <mailto:korg_mono-poly%40yahoogroups.com>, "Alain" <hubertalain@...>
> wrote:
> >
> > Hello Sophie.
> >
> > Well, is it simply the terms used that you don't quite get, like
> VCO, VCF, FM, and such ?
> > Or is it what the result of those mods would be ?
> > Or maybe a combination of the two ?
> >
> > Let's take them one by one:
> >
> > 1-VCO -> Cutoff FM
> >
> > Would take the output of the oscillators, and control the frequency
> of the filter cutoff. That would result in FM (audio frequency
> modulation) of the filter. The equivalent of turning the cutoff knob
> really really fast.
> >
> > 2-VCO -> VCA FM
> >
> > Same principle, but controlling the volume instead of the filter
> cutoff. (actually that would be technically called AM, not FM, for
> amplitude modulation)
> >
> > 3-VCO1 -> VCO(x) FM
> >
> > Taking the output of oscillator 1 to control the pitch of other
> oscillators. Frequency modulating other VCOs. (Like you can already do
> now with MG1 controlling the pitch but much, much faster)
> >
> > 4-LFO speeds increase by adding caps
> >
> > Getting faster speeds from MG1 or MG2 by adding, or better yet
> changing values of, timing capacitors (or resistors) in the electronic
> circuits that compose those LFOs. Which ones ?
> > Well to know that, you have to have some technical knowledge or
> background in electronics.
> >
> > 5- Audio in -> VCF/VCA
> >
> > Add a connector to allow external signals (other synths, electric
> guitar, etc...) to pass through the filter (VCF), or final amp (VCA)
> for using the MP as an "effect" box.
> >
> > 6-Suboscillators via divide circuit to every square
> >
> > Build additional circuits to effectively add sub-oscillators
> (oscillators playing one or more octave bellow the source) to each of
> the square wave output of the oscillators.
> >
> >
> > Hope this helps a little...
> >
> >
> > Alain.
> >
> >
> >
> > --- In korg_mono-poly@yahoogroups.com
> <mailto:korg_mono-poly%40yahoogroups.com>, Sophie Caroline Bernhard
> <sophiebernhard@> wrote:
> > >
> > > Hi Johan, Alain and all,
> > >
> > > I have to admit it, I am a littler lost with modifications
> > >
> > > Where could I get some infos to understand better about those
> > > modifications Johan wants to make?
> > > Is there a book, a course (a secret potion)?
> > >
> > > Many thanks in advance for your time in this
> > >
> > > Sophie
> > >
> > >
> > >
> > > On 11 Feb 2010, at 21:51, "Alain" <hubertalain@> wrote:
> > >
> > > > Good mod choices, Johan.
> > > > I like the CHD Elektro MIDI retrofit better than the Mungo. It's a
> > > > bit more expensive, but comes already complete and is a more
> elegant
> > > > solution for the MP. But that's only my personal opinion.
> > > >
> > > > A word of advice,if I may. When dealing with mods that concern the
> > > > VCOs, extra care must be taken, as those SSM2033 are close to
> > > > impossible to find as replacement chips, if ever a mod destroys one
> > > > (or more) of them.
> > > >
> > > > For this reason, I'd suggest starting with the filter mods. If ever
> > > > you inadvertently destroy the SSM2044, there are plenty available
> > > > (and inexpensive) on Ebay to replace it. Moreover, it is in a DIP
> > > > socket for easy removal. The SSM2033 are also in a socket, but have
> > > > their Tempco resistors glued on them and soldered to the main pcb.
> > > >
> > > > The LFO speed increase is entirely feasible, but also be aware that
> > > > doing so to MG2 might not trigger the arpeggiator correctly
> passed a
> > > > certain speed (cpu interrupt timing limitation).
> > > >
> > > > Sub-osc via divide is a great idea to get a little more "meat" out
> > > > of the low end.
> > > >
> > > > Do you have any schematics to start with, or are you going to
> > > > engineer them from scratch ?
> > > >
> > > > Alain.
> > > >
> > > > --- In korg_mono-poly@yahoogroups.com
> <mailto:korg_mono-poly%40yahoogroups.com>, "JohanI" <johan.inkinen@>
> > > > wrote:
> > > > >
> > > > > Hi everyone! Thanks for the welcome! :)
> > > > >
> > > > > Well I've been thinking of doing these mods:
> > > > >
> > > > > VCO->Cutoff FM
> > > > > VCO->VCA FM
> > > > > VCO1->VCO(x) FM
> > > > > LFO speeds increase by adding caps
> > > > > Audio in -> VCF/VCA
> > > > > Suboscillators via divide circuit to every square
> > > > >
> > > > > Oh, and also adding midi, either via Mungo Enterprises Midi
> > > > Retrofit or this one : http://www.chd-el.cz/index.php?id=409
> <http://www.chd-el.cz/index.php?id=409>
> > > > >
> > > > > I consider myself a beginner in synthmodding, have done a couple
> > > > on the korg poly800 (moog slayer, 12/24db filterswitch, fm800
> and so
> > > > on) and siel exp80 (similar architecture as poly800). Also working
> > > > on fitting the Mungo Enterprises midikit in a Juno6 atm.
> > > > >
> > > > >
> > > > >
> > > > > --- In korg_mono-poly@yahoogroups.com
> <mailto:korg_mono-poly%40yahoogroups.com>, "Alain" <hubertalain@> wrote:
> > > > > >
> > > > > > Yes Johan, welcome!
> > > > > >
> > > > > > I've already done a simple mod on mine, to convert arpeggiator
> > > > trigger input from s-trigger to pulse.
> > > > > > I also plan to add a sample-and-hold with the clock source as
> > > > either MG1 or MG2...
> > > > > >
> > > > > > Tell us what you want to mod on your MP!
> > > > > >
> > > > > > Alain.
> > > > > >
> > > > > >
> > > > > > --- In korg_mono-poly@yahoogroups.com
> <mailto:korg_mono-poly%40yahoogroups.com>, Florian Anwander
> > > > <fanwander@> wrote:
> > > > > > >
> > > > > > > Hello Johan,
> > > > > > >
> > > > > > > welcome to the group!
> > > > > > >
> > > > > > > Comment from new user:
> > > > > > > > hello. i would like to do some modifications on my mp and
> > > > come here
> > > > > > > > for help...
> > > > > > >
> > > > > > > Let us know what you want to modify.
> > > > > > >
> > > > > > > Florian
> > > > > > >
> > > > > >
> > > > >
> > > >
> > > >
> > >
> >
>
>

Thank you for your reply!

all the best
Sophie

--- In korg_mono-poly@yahoogroups.com, Alan Dicker <alanmdicker@...> wrote:
>
> Totally acquired by playing around with the machines in question both of the
synthesis front and on the electronics front and reading up on it at the time. 
I could read and read a book on electronic font to back and not understand it
until you were under the hood of a synth with the actually objects in front of
you.
> As for synthesis I've been writing music with them for 12 years and I'm still
learning in all areas of production.  the explanation of one thing wont make
sense until you know the explanation of another.  take addictive synthesis for
instance.  Until you have learned how a waveform shape is made up of particular
sine wave harmonics additive synthesis wont make sense.  once you do understand
that the concept of subtractive synthesis or the removal or harmonics through
filtering then makes even more sense.  then there is the whole other world of
FM. phase distortion and so on. 
> Things just start fit in to place one by one and I find teaching your self
means you learn everything allot more fundamentally than if you were just being
told it.
>  
> Googel is the teacher ;o)
>
> --- On Fri, 12/2/10, lakaband_in_uk <sophiebernhard@...> wrote:
>
>
> From: lakaband_in_uk <sophiebernhard@...>
> Subject: [korg_mono-poly] Re: New member Johan Inkinen - help for
Modifications
> To: korg_mono-poly@yahoogroups.com
> Date: Friday, 12 February, 2010, 12:36
>
>
>  
>
>
>
> Hi Alain,
>
> and thank you so much for this clarification. I know what an oscillator or a
filter is, but I have to admit that I could do with a bit more knowledge.
>
> In fact, I always wonder as to how to get some more knowledge about synthesis
and haven't found anything suiting my needs yet, really: either one has to look
into books - and sometimes things can be a bit too abstract - or one can attend
courses but apart from the online Berklee College in the US (that promotes
learning via softwares such as Reason and Absynth) I haven't found anything.
>
> How did you (Alain and all of you reading this) acquire you knowledge about
synthesis, apart from your own trying and tweaking?
>
> Thanks for reading!
>
> --- In korg_mono-poly@ yahoogroups. com, "Alain" <hubertalain@ ...> wrote:
> >
> > Hello Sophie.
> >
> > Well, is it simply the terms used that you don't quite get, like VCO, VCF,
FM, and such ?
> > Or is it what the result of those mods would be ?
> > Or maybe a combination of the two ?
> >
> > Let's take them one by one:
> >
> > 1-VCO -> Cutoff FM
> >
> > Would take the output of the oscillators, and control the frequency of the
filter cutoff. That would result in FM (audio frequency modulation) of the
filter. The equivalent of turning the cutoff knob really really fast.
> >
> > 2-VCO -> VCA FM
> >
> > Same principle, but controlling the volume instead of the filter cutoff.
(actually that would be technically called AM, not FM, for amplitude modulation)
> >
> > 3-VCO1 -> VCO(x) FM
> >
> > Taking the output of oscillator 1 to control the pitch of other oscillators.
Frequency modulating other VCOs. (Like you can already do now with MG1
controlling the pitch but much, much faster)
> >
> > 4-LFO speeds increase by adding caps
> >
> > Getting faster speeds from MG1 or MG2 by adding, or better yet changing
values of, timing capacitors (or resistors) in the electronic circuits that
compose those LFOs. Which ones ?
> > Well to know that, you have to have some technical knowledge or background
in electronics.
> >
> > 5- Audio in -> VCF/VCA
> >
> > Add a connector to allow external signals (other synths, electric guitar,
etc...) to pass through the filter (VCF), or final amp (VCA) for using the MP as
an "effect" box.
> >
> > 6-Suboscillators via divide circuit to every square
> >
> > Build additional circuits to effectively add sub-oscillators (oscillators
playing one or more octave bellow the source) to each of the square wave output
of the oscillators.
> >
> >
> > Hope this helps a little...
> >
> >
> > Alain.
> >
> >
> >
> > --- In korg_mono-poly@ yahoogroups. com, Sophie Caroline Bernhard
<sophiebernhard@ > wrote:
> > >
> > > Hi Johan, Alain and all,
> > >
> > > I have to admit it, I am a littler lost with modifications
> > >
> > > Where could I get some infos to understand better about those
> > > modifications Johan wants to make?
> > > Is there a book, a course (a secret potion)?
> > >
> > > Many thanks in advance for your time in this
> > >
> > > Sophie
> > >
> > >
> > >
> > > On 11 Feb 2010, at 21:51, "Alain" <hubertalain@ > wrote:
> > >
> > > > Good mod choices, Johan.
> > > > I like the CHD Elektro MIDI retrofit better than the Mungo. It's a
> > > > bit more expensive, but comes already complete and is a more elegant
> > > > solution for the MP. But that's only my personal opinion.
> > > >
> > > > A word of advice,if I may. When dealing with mods that concern the
> > > > VCOs, extra care must be taken, as those SSM2033 are close to
> > > > impossible to find as replacement chips, if ever a mod destroys one
> > > > (or more) of them.
> > > >
> > > > For this reason, I'd suggest starting with the filter mods. If ever
> > > > you inadvertently destroy the SSM2044, there are plenty available
> > > > (and inexpensive) on Ebay to replace it. Moreover, it is in a DIP
> > > > socket for easy removal. The SSM2033 are also in a socket, but have
> > > > their Tempco resistors glued on them and soldered to the main pcb.
> > > >
> > > > The LFO speed increase is entirely feasible, but also be aware that
> > > > doing so to MG2 might not trigger the arpeggiator correctly passed a
> > > > certain speed (cpu interrupt timing limitation).
> > > >
> > > > Sub-osc via divide is a great idea to get a little more "meat" out
> > > > of the low end.
> > > >
> > > > Do you have any schematics to start with, or are you going to
> > > > engineer them from scratch ?
> > > >
> > > > Alain.
> > > >
> > > > --- In korg_mono-poly@ yahoogroups. com, "JohanI" <johan.inkinen@ >
> > > > wrote:
> > > > >
> > > > > Hi everyone! Thanks for the welcome! :)
> > > > >
> > > > > Well I've been thinking of doing these mods:
> > > > >
> > > > > VCO->Cutoff FM
> > > > > VCO->VCA FM
> > > > > VCO1->VCO(x) FM
> > > > > LFO speeds increase by adding caps
> > > > > Audio in -> VCF/VCA
> > > > > Suboscillators via divide circuit to every square
> > > > >
> > > > > Oh, and also adding midi, either via Mungo Enterprises Midi
> > > > Retrofit or this one : http://www.chd- el.cz/index. php?id=409
> > > > >
> > > > > I consider myself a beginner in synthmodding, have done a couple
> > > > on the korg poly800 (moog slayer, 12/24db filterswitch, fm800 and so
> > > > on) and siel exp80 (similar architecture as poly800). Also working
> > > > on fitting the Mungo Enterprises midikit in a Juno6 atm.
> > > > >
> > > > >
> > > > >
> > > > > --- In korg_mono-poly@ yahoogroups. com, "Alain" <hubertalain@ >
wrote:
> > > > > >
> > > > > > Yes Johan, welcome!
> > > > > >
> > > > > > I've already done a simple mod on mine, to convert arpeggiator
> > > > trigger input from s-trigger to pulse.
> > > > > > I also plan to add a sample-and-hold with the clock source as
> > > > either MG1 or MG2...
> > > > > >
> > > > > > Tell us what you want to mod on your MP!
> > > > > >
> > > > > > Alain.
> > > > > >
> > > > > >
> > > > > > --- In korg_mono-poly@ yahoogroups. com, Florian Anwander
> > > > <fanwander@> wrote:
> > > > > > >
> > > > > > > Hello Johan,
> > > > > > >
> > > > > > > welcome to the group!
> > > > > > >
> > > > > > > Comment from new user:
> > > > > > > > hello. i would like to do some modifications on my mp and
> > > > come here
> > > > > > > > for help...
> > > > > > >
> > > > > > > Let us know what you want to modify.
> > > > > > >
> > > > > > > Florian
> > > > > > >
> > > > > >
> > > > >
> > > >
> > > >
> > >
> >
>