Some Explanation On Schematics - Farfisa Combo Compact User Manual

Some explanation on schematics

c
•
SE 10: Operating
s i
chemat
The schematics show the general principles, which are the following ones:
a) The signals are originated by oscillators
(i.
•
C produces all C s
name e. G 10
b)
The Vibrato is obtained operating directly on the oscillators of the various notes.
c)
Every key has three contacts: the lower one operates on 16' frequencies, the medium one operates on
�· frequencies, the upper one operates on
d) All the contacts related to every octave, C
filters; these ends are represented by common bars and each one them is connected by means of a shielded
cable to a series of switches operated by the MTB ON/OFF tab.
e) The MTB switches are
position. In this case, inserting one tone
filter FD 10, where part of the signals is blended and then conveyed to filter FA 10 for the formation of the
sharp tones (oboe, trumpet, strings).
The signals proceeding from filter FA tO
conveyed to the L.F. p r ea mplifier. At
interesting the signals conveyed to
be
signals, ready to conveyed,
f) When MTB is inserted, the switches convey the signals
FD 10 through MTB stops (
special in take of MTB, where
veyed to the outlet of MTB.
The L.F. preamplifier is connected only to
veyed to this device through t6'.
g) When All Booster
c »
veyed, at constant level, to filter FD-10 through MT6
II
•
SE Simplified keying schematics for Treble and Manual Bass.
:
the
It shows wiring of the
12:
•
SE Circuit diagram of Treble registers
The drawing reports the connections
and the filters.
In the left top corner, framed in
13:
•
SE Circuit diagram of Pedal registers, Vibrato and Reverb.
The drawing showing the Manual Bass
regulation of single notes, while the drawing related to Vibrato and Reverb shows Potentiometer R 536 for the
regulation of the time of Reverberation.
14:
•
of Master oscillators
SE Schematics
10).
amplifier (PS
The schematics show the values of all components assembled in the printed circuits for repair purpose.
15:
SE. Circuit diagram of Power Supply, Preamplifier and Reverb.
Complete electric schematis, showing the voltage rating and the features of electric com p onents. Al m o st
in the centre of the page it Is indic ated the Swell Pedal photoresistor operating as volume control.
s
tO. Each one of them produces all the frequencies of same
G
G 10 ·A prc:x:luces all As, etc,).
,
4'
frequencies.
•
B, for 16' or 8' or 4', have common ends for connection to
meant to convey the si gnals to the tone stops when the MTB tab is in OFF
stop (or several stops at the same time), the signals are conveyed to
r e t u n to the tone stops and through the inserted tab,
r
the same time, in the filter
the low pass filter, takes
�
throug the special tone s to ps
8'. 4').
t6'.
The total blending of signals in FD 10 is then conveyed directly to the
the filtered signals, available
of MTB and amplifies therefore only the
the outlet
8' - 4 '
stops (Green tabs) with the exclusion of the tone stops
is inserted, the signals proceeding from the common bars are
op s 16',
st
various notes, making reference
interesting t he tone stops and the connections between the registers
a· square, it is shown
a the Pedalboard stops indicates the potentiometers for the volume
nd
(G 10),
filters
FD 10, an attenuation of the higher
place, giving way to an output of
(bass, flute), to the L. F. preampJif, i er.
proceeding from the common
at the outlet No. 10 of FD 10 (sweet tune) are con­
8', 4'.
to one note only (A).
the schematic diagram of MTB device.
(FD 10), (FA 10), Vibrato
they are
harmonics,
sweet tune
bars t o filter
signals c on
·
(white tabs).
pe rmanently con·
circuit and Pedal
25