Doepfer A-104 four-fold Trautonium Formant Filter - Manual (Page 4)

A-104 Trautonium Formant Filter System A - 100 doepfer
4
Fig. 2: Frequency response of band pass and low
pass
2 Freq.
Control 2 is used to adjust the filter frequency (see
fig. 2):
• In band pass mode i.e. the middle frequency f
M
• In low pass mode i.e. the cutoff frequency f
C
The frequency range for each filter is about 50Hz ...
5kHz (same as for the Trautonium filter).
3 Resonance
Control 3 is used to adjust the filter resonance (or
emphasis or Q, see fig. 2):
• In band pass mode i.e. the band width
• In low pass mode i.e. frequency emphasis
around the cutoff frequency
Self-oscillation - as for some other filters of the A-100
(e.g. A-120, A-121, A-122, A-123 and so on) - is not
available.
4 Mode
The three-position switch 4 is used to select the mode
of the corresponding filter:
• band pass (upper position)
• off (middle position)
• low pass (lower position).
5 Level
Attenuator 5 is used to adjust the signal level of the
corresponding filter (share in the mix output socket ").
Frq.
Freq.
Out
Frq.
Res.
Freq.
Res.
Out
f
C
f
M