KVR Audio

banga45 · Post by **banga45** » Sun Feb 11, 2007 2:52 pm

Hi,

just tested a korg mono/poly
He works fine on all waveform exept pwm.
When I put the 4 osc on pwm, I have a very very low sound like if the cutoff was to the minimum or something like that.
After many many test of turning pot, no result.

What do you think about that??

regards
Banga

BertKoor · Post by **BertKoor** » Sun Feb 11, 2007 9:21 pm

Sometimes a part of a synth just dies. It can be repaired if you take it to a Korg service center which has the right parts in stock. And that can be a problem... Call them!

Edit: you DO know that there is a knob that changes the pulse width? Only works when square wave is selected. Can also be the amount that LFO influences the pulse width (of square wave.) Sounds a bit like the sound gets thinner and fuller, or like a chorus effect when modulated by LFO.

I'm not sure which knob you mean....

banga45 · Post by **banga45** » Mon Feb 12, 2007 8:20 am

thanks for your answer Bertkoor,

in fact when I turn on the monopoly and that I test all the waveform (sine, square, pwm and pw)
All of them give me the awaited sound except the pwm.
This is strange because the synth has normaly been tested and that, in my poor opinion, it seems strange that the 4 osc are defected on pwm, no?
But if I'm not wrong, there is no reason (filter or wathever) that pwm doesn't produce sound when others wave make it.
Perhaps can I up-load a pic?

thanks
Banga

BertKoor · Post by **BertKoor** » Mon Feb 12, 2007 9:31 am

Right... If you've demo'd the synth with intentions of buying it, let's assume that one waveform is not functional so you should get it cheaper.

I'm really confused by the terminology; waveforms being called pulse width and pulse width modulation, since modulation in my book is something you do to it and not a quality of the waveform itself.

Maybe someone else that has used this synth himself can clarify what kind of waveform "PWM" exactly is.

banga45 · Post by **banga45** » Mon Feb 12, 2007 6:28 pm

thanks Bert, I'll make a little check-up

ps:I'm pretty new to this forum and I most say that it's very pleasant to see how people takes time to read and answer, thanks.

peace
Banga

jupiter8 · Post by **jupiter8** » Mon Feb 12, 2007 6:43 pm

The monoploy indeed has a PW and a PWM waveform.

And you choose the mod sources with these knobs.

It seems kind of weird that all 4 osc. has crapped out on the same waveform. Have you fiddeled with the controls in the second picture ? It is possible to "skew" the pulsewitdh so far the sound more or less dissappears.

EDIT: Do the MGs work on other targets ? If one of them is not outputting any voltage for some reason the sound could probably be very low.

c_huelsbeck · Post by **c_huelsbeck** » Mon Feb 12, 2007 7:32 pm

Well, Banga45, what happens if you turn the knobs that jupiter8 is showing?

banga45 · Post by **banga45** » Mon Feb 12, 2007 9:32 pm

Hey!

Thanks, I didn't hope so much!
Unfortunately when reproducing the same "schéma", the problem still persist.

Something I omited is that, on the pwm waveform, when I turn the cutoff (low) and the resonance (high), I have a normal volume sound.Filtered but normal

The problem is only at normal freq.

Thanks a lot for your help, I'll probably go tomorrow to see what happen and of caurse, will put the answer here.

regards
Banga

Korg Monopoly PWM problem