Sequential Pro One - Oscillator B; Oscillator B Sawtooth and Triangle Output

2-3 OSCILLATOR B
OSC B is similar to OSC A except that besides being a pitch source it can be a
modulation source and can therefore operate as an LFO with or without keyboard
control. Only the differences between OSC B and OSC A will be mentioned. 5116 LO
FREQ switch extends the range of R139 OSC B FREQUENCY knob by connection to -
15V. The KYBD CV path through R142 contains 51 17 for disabling keyboard tracking.
The unused S SYNC input is bypassed by C115 to prevent synchronization to noise.
OSC B's output circuitry differs from OSC A by having the SAWTOOTH and PULSE
outputs amplified by differential buffer U105-1 with a gain of 1. For the TRIANGLE
output, R197 contributes enough negative dc voltage to pull the triangle level down to
be symmetrical about ground level (rather than positive-going) so as to not offset
modulation destinations, Figure 2-5 shows how the waveforms normally add together.
Besides
driving R1133 MIX OSC B knob, the OSC B output is tapped for the
MODULATION circuitry, discussd below.
TRIANGLE
SAWTOT1
TRIANGLE
Figure 2-5
OSCILLATOR B SAWTOOTH and TRIANGLE OUTPUT
AND SAWTOOTH
3: