Elka synthex schematics

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schematic diagrams

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HOW TO RECALIBRATE ELKA SYNTHEX' OSCILLATORS.
The board you have to look at is n° 5840, which is at the bottom of the 4-board-group
on the left side.

SOUND GENERATOR (OSCILLATOR) CALIBRATION.

The 16 oscillators of Synthex' voices are digital, their tuning ls controlled only by
number codes that cannot change as time passes by, so the tuning is stable and reliable.
Since the voice - oscillators must be frequency-controlled by means of the LFO and the
pitch bend, 4 reference frequency generators are used to which the voice-oscillators
link; they can be imagined as 4 electronlc diapason that can be modulated by the LFO
and by the bend. We can refer to these 4 generators as: Gen A, Gen B, Gen C, Gen D.

In SPLIT and DOUBLE mode the assignation is as follows:

Gen A: OSC-1 upper ( 4 voices)
Gen B: OSC-2 upper ( 4 voices)
Gen C: OSC-l lower ( 4 voices)
Gen D: OSC-2 lower ( 4 voices)

In NORMAL mode the assignation ia as follows:

Gen A: OSC-1 upper ( 8 voices)
Gen B: OSC-Z upper ( 8 voices)

board | ------------------------------------------------ --
-------------- | 5840
| T10 T9 T8 T7 T6 T5 T4 T3 T2 T1

Gen D Gen C Gen B Gen A

OSC-ZL OSC-1L OSC-2U OSC-1U

The generators calibration is divided into 4 steps:

step-1: starting settlngs

step-2: calibration of Gen B: OSC-2 referring to Gen A: OSC-1
step-3: calibration of Gen C: OSC-1L referring to Gen A: osc-1u
step-4: calibration of Gen D: OSC-ZL referring to Gen A: OSC-1U

If for some of these steps you reach the limit of one trimmer, you can solve the problem
by using the corresponding Gen A trimmers 1or 2, repeating of the three steps;