Doepfer

Ok, so I tried the cap modifications (mounted them in parallel with the 10nF ones, straight onto the board): 

=> 470nF=> Efficient phase shifting from around 1kHz, down to 50Hz
=> 1MF... shift efficient down to less than 20Hz, but goes south around 120Hz

I'm staying with 470. 

Thanks guys!


--- In Doepfer_a100@yahoogroups.com, "ctujoao" <ctujoao@...> wrote:
>
> Dear sir, you made my day!
> I will go to bed a bit less stupid tonight. 
> I didn't think trough the filtering of other frequencies, with anything other than all pass. 
> 
> Thank you very much for the explanation. 
> 
> 
> --- In Doepfer_a100@yahoogroups.com, Florian Anwander <fanwander@> wrote:
> >
> > Hello
> > 
> > > Now: isn't the phase shift of this shifted signal, due to the
> > > physical effect of passing through some sort of filter (something
> > > like notch or BP)?
> > No.
> > 
> > What we call a "filter circuit" is a circuit which has two 
> > characteristics, which are both related to the center frequency, and 
> > which change above and below the center frequency.
> > 1.) The phase of the output signal in relation to the input signal
> > 2.) The level of the out signal in relation to the input signal
> > 
> > In both cases this is not an abrupt change, but the change starts slowly 
> > somewhere below the center frequency and ends somwhere above.
> > Both characteristics change at "the same time".
> > 
> > We know five kinds of filters: Lowpass, Bandpass, Notch, Highpass, and 
> > Allpass
> > 
> > All of them have the phase behaviour in common.
> > 
> > But only four of them have the level behabviour in common:
> > * Lowpass: the output level above the center frequency is less than below
> > * Highpass: the output level above the center frequency is more than below
> > * Bandpass: the output level around the center frequency is more than 
> > below and above
> > * Notch: the output level around the center frequency is less than below 
> > and above
> > 
> > The allpass does not change the level, but still changes the phase.
> > 
> > You could use e.g. a Lowpass also for a phaser, but since there is also 
> > this level-thing, the phaser effect would stop soon above the center 
> > frequency: one ocatve above the center frequency there is nothing to mix 
> > with the input signal anymore - it is filtered away already. Same for 
> > all other types of filters. With exception of the allpass: The allpass 
> > provides the wonderful phase shift, wothout spoiling the game by muting 
> > the shifted frequencies.
> > 
> > A phaser works only with an allpass - nothing else. But the other way 
> > around: a phaser never can be used as a filter.
> > 
> > Florian
> >
>