Modular
2. AM and FSK
2.1 AM (Amplitude Modulation)
The
/ output ( )
amplitude varies linearly with the control voltage applied to "
AM in
" ( ).
The modulation amount can be adjusted with knob 'AM In' (See chapter 3: "Functions"). Negative
CVs will cause phase inversion of the
/ waveform
.
Examples:
Ring modulation with external
triangle signal
VCO volume control with
external envelope generator
AM in
patched with
/
output
(Feedback)
2.2 FSK (Frequency Shift Keying)
The frequency of the XR22 VCO is controlled by two
independent frequency control sections F1 and F2 with
independent manual frequency controls and CV ins;
either one or the other of these routes can be activated
by an external logic signal applied on socket "
FSKin
" ,
and/or by switch "
FSK
"
2
3
4
5 6
7
8 9
21
10
11
13 14
15 16
17
18 19
20
22
12
Objekt in Pfade:
4
4
14
Falsche Zahlen
.
Switch "
FSK
"
2
3
4
5 6
7
8 9
21
10
11
13 14
15 16
17
18 19
20
22
12
Objekt in Pfade:
4
4
14
Falsche Zahlen
selects the FSK mode: F1, F2 or self-
switching by the VCO's -output.
In self-keying mode the rising and falling edges of the
triangle waveform (and the hi/lo times of the square-
wave) can be separately adjusted.
Switch "com" is adding the F1-CVs to F2; this is to ensure 1V/oct. tracking if both routes are used
e.g. in the self-frequency shifting - mode.
Examples:
F1
activated.
LED=
green (
Switch "
FSK
"
2
3
4
5 6
7
8 9
21
10
11
13 14
15 16
17
18 19
20
22
12
Objekt in Pfade:
4
4
14
Falsche Zahlen
up)
F2
activated.
LED=
red
(
Switch "
FSK
"
2
3
4
5 6
7
8 9
21
10
11
13 14
15 16
17
18 19
20
22
12
Objekt in Pfade:
4
4
14
Falsche Zahlen
mid)
-
Mode (
F1+F2
activated)
(
Switch "
FSK
"
2
3
4
5 6
7
8 9
21
10
11
13 14
15 16
17
18 19
20
22
12
Objekt in Pfade:
4
4
14
Falsche Zahlen
low).
The oscillator frequency-shifts itself.
F1
and
F2
(
≙
falling and rising edges of the
triangle waveform) can be separately adjusted.
With external FSK control signal applied on "
FSK
in
"
(
Switch "
FSK
"
2
3
4
5 6
7
8 9
21
10
11
13 14
15 16
17
18 19
20
22
12
Objekt in Pfade:
4
4
14
Falsche Zahlen
middle position).
The oscillator switches between
F1
and
F2
,
depending on the logic control signal applied to
FSK in
2
3
4
5 6
7
8 9
21
10
11
13 14
15 16
17
18 19
20
22
12
Objekt in Pfade:
4
4
14
Falsche Zahlen
.
2
/
Output
ext. squarewave
signal on "FSK in"
F1
F2
...
F1
F1
F2
F2
Gain poti in
ccw positions of "0"
or AM-CVin < 0V
Gain poti in
cw positions of "0"
or AM-CVin > 0V
Squarewave
Output
/
Output
/
Output
...
Frequency 1:
"FSK in" = high
Frequency 2:
"FSK in" = low
/
- Output
/
- Output
/
Output
Ext. squarewave
signal applied
on "FSK in"
...
F1
F2
/
- Output
Gain pot in
ccw positions of "0"
or AM-CVin < 0V
Gain pot in
cw positions of "0"
or AM-CVin > 0V
/
- output
...
F1
F1
F2
F2
"FSK in" connected to - output:
-output
/
Output
Output
/
F1
F1
F2
F2
Gain poti in
ccw positions of "0"
or AM-CVin < 0V
Gain poti in
cw positions of "0"
or AM-CVin > 0V
Squarewave
Output
/
Output
/
Output
...
/
Output
ext. squarewave
signal on "FSK in"
F1
F2
...
/
Output
ext. squarewave
signal on "FSK in"
F1
F2
...
F1
F1
F2
F2
Gain poti in
ccw positions of "0"
or AM-CVin < 0V
Gain poti in
cw positions of "0"
or AM-CVin > 0V
Squarewave
Output
/
Output
/
Output
...
Frequency 1:
"FSK in" = high
Frequency 2:
"FSK in" = low
/
- Output
/
- Output
/
Output
Ext. squarewave
signal applied
on "FSK in"
...
F1
F2
/
- Output
Gain pot in
ccw positions of "0"
or AM-CVin < 0V
Gain pot in
cw positions of "0"
or AM-CVin > 0V
/
- output
...
F1
F1
F2
F2
"FSK in" connected to - output:
-output
/
Output
Output
/
F1
F1
F2
F2
Gain poti in
ccw positions of "0"
or AM-CVin < 0V
Gain poti in
cw positions of "0"
or AM-CVin > 0V
Squarewave
Output
/
Output
/
Output
...
/
Output
ext. squarewave
signal on "FSK in"
F1
F2
...
/
Output
ext. squarewave
signal on "FSK in"
F1
F2
...
F1
F1
F2
F2
Gain poti in
ccw positions of "0"
or AM-CVin < 0V
Gain poti in
cw positions of "0"
or AM-CVin > 0V
Squarewave
Output
/
Output
/
Output
...
Frequency 1:
"FSK in" = high
Frequency 2:
"FSK in" = low
/
- Output
/
- Output
/
Output
Ext. squarewave
signal applied
on "FSK in"
...
F1
F2
/
- Output
Gain pot in
ccw positions of "0"
or AM-CVin < 0V
Gain pot in
cw positions of "0"
or AM-CVin > 0V
/
- output
...
F1
F1
F2
F2
"FSK in" connected to - output:
-output
/
Output
Output
/
F1
F1
F2
F2
Gain poti in
ccw positions of "0"
or AM-CVin < 0V
Gain poti in
cw positions of "0"
or AM-CVin > 0V
Squarewave
Output
/
Output
/
Output
...
/
Output
ext. squarewave
signal on "FSK in"
F1
F2
...
/
Output
ext. squarewave
signal on "FSK in"
F1
F2
...
F1
F1
F2
F2
Gain poti in
ccw positions of "0"
or AM-CVin < 0V
Gain poti in
cw positions of "0"
or AM-CVin > 0V
Squarewave
Output
/
Output
/
Output
...
Frequency 1:
"FSK in" = high
Frequency 2:
"FSK in" = low
/
- Output
/
- Output
/
Output
Ext. squarewave
signal applied
on "FSK in"
...
F1
F2
/
- Output
Gain pot in
ccw positions of "0"
or AM-CVin < 0V
Gain pot in
cw positions of "0"
or AM-CVin > 0V
/
- output
...
F1
F1
F2
F2
"FSK in" connected to - output:
-output
/
Output
Output
/
F1
F1
F2
F2
Gain poti in
ccw positions of "0"
or AM-CVin < 0V
Gain poti in
cw positions of "0"
or AM-CVin > 0V
Squarewave
Output
/
Output
/
Output
...
/
Output
ext. squarewave
signal on "FSK in"
F1
F2
...
F1/com
F2
F1 Fine Tune
F2 Fine Tune
F1/com CV ins
F2 CV ins
+
Switch
"com"
Frequency
Control
VCO
FSK in
Switch "FSK"
F1
F2
Output
6
F1
F2
16
LO MID
HI
4
