last update: 18.Jan.2017
works best with Scope and good DMM (4,5digits with less than 1% tolerance)
make sure your device works without smoke, smell, all LEDs are on, your VCO/VCF/VCA works.
before you start, let the TTSH in a room with stable temperature, power on the TTSH for 30 min. before you start the calibration.
make sure you have no jumper on kbd/cv pcb header (was used in TTSH rev.1 buildguide)
Table of Content
Powersupply (for rev.3)
trim to excactly -15V/15V by usage of the Powersupply Multiturn trimmer, measure between -V and 0 and +V and 0
use a 12V - 24DC powersupply at the input.
Ring modulator
Positive Null
01) Put switch in DC position
02) Raise VCO 1 slider only
03) Monitor output with oscilloscope and adjust POS NULL for minimum output
Negative Null
01) Put switch in AC position
02) Raise VCO 1 slider only
03) Monitor output with oscilloscope and adjust NEG NULL for minimum output
Gain
01) Raise both sliders into Ring Modulator and set switch to DC
02) Adjust GAIN trimmer for 20Vpp maximum
VCO 1 to 3
V/oct adjustments (own Info: start with VCO1 - use the Mixer to doublecheck the same initial frequency and lowest/highest frequency to get the same values on all VCOs)
01) Monitor output with frequency counter or tuning standard
02) Depress low C and adjust frequency for 100Hz using coarse or fine tune slider
03) Depress high C and adjust 1V/OCT trimmer for 1600Hz
04) repeat 2 and 3 until C are correct
Frequency calibrate
01) Monitor output with oscilloscope or frequency counter
02) All FM sliders down
03) Remove keyboard CV from selected VCO
04) Put frequency slider far right (maximum)
05) Put fine tune slider – mid range
06) Adjust FREQ CAL for 8.33kHz
VCO-1
Pulse width
01) Monitor square wave output with oscilloscope and adjust SYMMETRY trimmer for 50% duty cycle.
VCO-2 Wave shape adjustments
Symmetry
01) Monitor triangle output with oscilloscope
02) Adjust TRI trimmer for best triangle waveform
DC offset adjust
01) Adjust OFFSET trimmer so the peaks of the triangle waveform is not flat or either end
Gain adjust
01) Monitor sine wave output with oscilloscope
02) Adjust GAIN for 10Vpp output
Purity adjust ( if you don`t get a SIN, give more gain/voltage, if you haven´t tested with a transistortester your 2N3958 - should be defect)
01) Adjust PURITY for best sine waveform
It might b e necessary to readjust calibrations after performed in the order listed.
VCF
Frequency calibrate
01) Monitor VCF output with an oscilloscope or frequency couter
02) Initial frequency slider – left
03) Fine tune slider – mid range
04) Resonance slider – right
05) All VCF inputs sliders – down
06) Disconnect or use dummy plug for KYBD CV in
07) Adjust FREQ CALIBRATE for 10Hz output
V/oct adjust
01) Repeat steps for frequcny calibrate but reconect keyboard
02) Depress low C (0 volts)
03) Adjust initial frequency slider and fine tune slider for 200Hz
04) Depress C three octaves higher and adjust 1V OCT trimmer for 1600Hz
05) Repeat step 2-4 until low C remains at 200Hz and C3 remains at 1600Hz
Output offset
01) Monitor VCF output with oscilloscope
02) Initial frequency, fine tune, and resonance slider – left
03) All input sliders down
04) Adjust OUTPUT OFFSET for minimum DC output. Movement of the initial frequency slider should not cause more than 1V deflection
Gain adjust
01) Open VCF initial frequency slider – right
02) Resonance slider – left
03) Raise VCO1 input slider and adjust GAIN for same amplitude as measure at VCO1 output
VCA
Linear gain
01) Monitor VCA output with oscilloscope
02) Patch VCO3 saw to VCA ‘VCF Input’ jack and raise audio slider fully
03) Put initial gain slider – left (minimum)
04) Raise VCA AR control slider all way
05) Depress and hold the manual start button and adjust LINEAR GAIN for 10Vpp maximum signal output
Control rejection
01) Repeat steps 1-3 for linear gain adjustment
02) Patch VCO2 LF sine wave (2Hz) into VCA AR control input
03) Close VCA VCF input slider
04) Adjust CONTROL REJ for minimum output
High frequency reject
01) No adjustment necessary
Exponential gain
01) Set EXP’L GAIN trimmer fully clockwise
Experiment with exponential setting…
Internal Clock
Init frequency
01) Monitor Internal clock output with an oscilloscope
02) Put rate slider at max
03) Adjust INIT trimmer so the square wave doesn’t disappear at max rate setting
Pulse width
01) Monitor Internal clock output with an oscilloscope
02) Put RATE slider at max
03) Adjust WIDTH trimmer for 50% duty cycle