Modular
4. Adjustment
The VCO is already carefully adjusted to 1V/Oct.
If you realize that the XR22 VCO isn't in tune with your other analog synthesizer equipment, it may be
necessary to adjust it.
Procedure (Suggestion)
1. Switch on your equipment and the XR22 VCO and
wait ½ hour until the oscillators have the right
temperature.
2. Bring octave switches F1 and F2 in middle
position. Adjust F1 & F2 knobs & to ≈ middle
position (≈5-6 on scale)
3. Connect a CV from a keyboard (or similar) both to
your favorite VCO's 1V/oct. input and to the XR22
VCO F1/com 1V/oct. input .
Put switch "com" and switch "FSK" in upper
position ("F1").
4. Play a note on your keyboard in the middle range,
e.g. "C", or "c". The note should be nearby to the
tone you have adjusted on the XR22.
5. Adjust pot "F1" until the pitch of the XR22 is the
same like that of the 2nd VCO.
6. Play a note ≈ 2-3 octaves higher. Adjust trimmer "F1
1V/oct" (see above) until the XR22 VCO is tracking
to the 2nd VCO.
7. Go back to step "4" and repeat all other steps until
both oscillators are in tune.
8. Repeat the same procedure with "F2" (with "FSK"
in middle position and F2 1V/Oct. Input ).
9. After this it is necessary to readjust the octave
tuning for switches F1 and F2 , too.
10.Disconnect the CV from your keyboard to the XR22
and bring FSK switch in upper position ("F1").
11.Turn F1 pot in fully counterclockwise and octave
switch in middle position.
12.Tune your 2nd VCO until it pitches with the XR22
VCO.
13.Play a note 2 octaves higher on the 2nd VCO and
bring the octave switch in right position ("+2)
14.Adjust trimmer "+2 Octaves" until it matches.
15.Repeat step 11and the following until the trimmer
no longer needs to be adjusted.
16.Turn F1 pot in fully clockwise and octave switch
in middle position.
17.Tune your 2nd VCO until it pitches with the XR22
VCO.
18.Play a note 2 octaves lower on the 2nd VCO and
bring the octave switch in left position ("-2).
19.Adjust trimmer "-2 Octaves" until it matches.
20.Repeat step 16 and the following until the trimmer
no longer needs to be adjusted.
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