Elektor Formant Modular

i wonder if its a common problem with the formant, or if its just mine..
if i modulate. say, the vca with a square lfo, i can actually HEAR the lfo, 
it doesnt only modulate, but you can also hear the "clicks" from the lfo 
(just af you put headphones to the lfo output), the same thing happens if i 
mod, the filter... there is no problem if i use the sine/triangle lfo... but 
when it comes to "steep" lfo waves.. i can hear a click....
hope someone can help


thanks
troels.

_________________________________________________________________
F\ufffd gode tilbud direkte i din mailbox http://jatak.msn.dk

--- In ElektorFormant@yahoogroups.com, "troels jrgensen" 
<the19thbear@h...> wrote:
> 
> i wonder if its a common problem with the formant, or if its just 
mine..
> if i modulate. say, the vca with a square lfo, i can actually HEAR 
the lfo ...

I think it is normal, a way to avoid this problem should be to 
synchronise the square with the modulated wave to avoid the cut of 
the sine (or other waveform) when its amplitude is not zero (zero 
crossing circuit, like triac drivers !). Or another way should be to 
reduce the slew rate of the LFO by filtering the signal  (a simple R-
C). I observed the same thing with my others synthesizers (DX7 or 
D50). When the slope of the envelope generator is very quick, I can 
hear a plop for every note. As I remember, I think we can even hear 
something like that in the album "Switched on Bach" (1968)from W. 
Carlos, precisely in the very original second movment of the 3° 
Brandb. So we can also think it is an element of electronic music ?

Stephen
(from France)

. Or another way should be to
>reduce the slew rate of the LFO by filtering the signal  (a simple R-
>C). aha.. i get it... but what is R-C.... im  not educated at all..

thanks
troels.

_________________________________________________________________
F\ufffd gode tilbud direkte i din mailbox http://jatak.msn.dk

R-C is a resistor-capacitor combination.
This creates a sort of slow on-off for an LFO.
You can also think of it as a low-pass filter. The edges of a square wave
represent a high frequency, wich can be filtered out with an R-C network.
same effect if you would modulate a VCO with an ADSR with fast attack and
release times, you would also hear the clicks.

greetings !