Sequential Pro One - DAC Scale; Tuning; Tuning Patch

SECTION 5
SERVICE
/
I
,/
5-0 INTRODUCTION
4
This section contains fdl tuning and trimming procedure as well as instructions for
using the Digital Interface.
5-1 DAC SCALE
This adjustment should not be performed as part of the tuning procedure. In fact,
readjustment
may only be necessary if a repair has been made. Whenever this
adjustment is made the Pro-One will have to be completely retuned- digit
voltmeter (DVM) is required.
1. Connect DVM to back-panel CV OUT jack.
2. Hit CO and note reading. The reading will be approximately 0.883V. (The absolute
value of this reading is not critical.)
3. Hit C3 and note reading, which shoukd be the value read in step 2, plus exactly 3V. If
necessary, adjust Rllgl DAC SCALE for the exact reading; e.g. 3.083~.
4. Repeat steps 2 and 3 as required to establish an exact 3-V difference between CV
OUT played by C3 and c3.
5-2 TUNING
1. Patch according to Figure 5-0. Start a full tuning by presetting both R120 OSC A
and R140 OSC B OFFSET trimmers to the middle of their range. For component
locations,
see Figure 5- 1.
h
Figure 5-0
TUNING PATCH