Oscillator B Test; Osc B Test Patch - Sequential Pro One Technical Manual

1-4 OSCILLATOR B l F 5 T
Figure 1-2
OSC B
TEST
PATCH
1. Patch according t o Figure 1-2.
2. Check t h a t
OSC B FREQUENCY knob range
exceeds
one octave. For reference,
play C2 and remember pitch. Then hold C1 and raise OSC
B
FREQ. The pitch should
increase smoothly, approaching t h e reference tone at 7
-
8 on t h e dial. A t 10 t h e pitch
should be
at least a whole s t e p above the reference.
3. Turn OSC B FKEQ
t o 0.
Check OSC B
OCTAVE switch by playing C2 and switching
octaves
down
t o 2, 1, and 0. NOTE: When
switching
octaves
with
a
key depressed, it is
normal to hear the pitch "jump"
between octaves.
4.
Switch
OSC
B
OCTAVE
to
2.
Switch
OSC 0 SAWTOOTH off.
Switch
OSC B
TRIANGLE on. The
difference between
the ''brassy"
sawtooth and
"dull1'
triangle wave
should be obvious. The triangle waveshape
has
very little harmonic
energy. Switch
OSC
I 3
TRIANGLE
off.
5. Switch
OSC B
PULSE
on. Rotate OSC B PULSE WIDTH knob
0
-
10,
listening f o r t h e
timbral effect of
varying harmonics. The pulse will
degenerate to
dc
(or
very
nearly
dc--99% duty
cycle)
at the extreme knob settings, resulting in no (or
very little) sound.
Find t h e setting where t h e second harmonic drops out (50% duty cycle). This normally
occurs
between dial markings 5 and 6.
6 . Switch OSC B LO FREQ on. Raise 6SC
B
FREQ t o about 6 t o more easily hear
OSC
B
"track" the keyboard at
lev$
frequencies. NOTE:
he
OSC B LO FREQ switch
extends
OSC
B's FREQ range
t o sub-audio. I t is
therefore
normal qhat
if
OSC
B FREQUENCY
is set to 10,
t h e LO
FREQ
s w i t c h will appear
to h a v e nd effect.
Switch
0 5 C B LO
FREQ to NORMAL.
/
7. Switch OSC B KYBD off and c h e c k t h a t OSC B
ceases "tracking" t h e
keyboard.