Circuit Descriptions Power Supply

-15 Volt Supply The -15 volt supply derives its regulation from the +15 volt supply through R8. When the output of the -15 volt supply is at the correct voltage, the junction of R8 and R12 is zero volts. The base of Q2 is referenced to zero volts through R9. Should the output of the minus supply increase, the voltage on the base of Q3 will also increase which begins to turn off Q3. Q2 conducts more current which requires Q4 to conduct more. Q4 drives the pass transistor (Q5) which then conducts...

Assemblydissassembly

NOTE These two screws MUST be replaced n the correct places. SECTION 2 CIRCUIT DESCRIPTIONS Board A-1 Each key on the keyboard has its own capacitor-resistor-diode network. The capacitors are normally charged to 15 volts until a key is depressed at which time the capacitor discharges through the diode creating a trigger pulse on the trigger bus rod. Q1 through Q4 are a monostable multivibrator which delays the trigger pulses 15 milliseconds to allow the gate and CV to stabilize. P1, the pitch...

Arp Odyssey Ii Front Panel Trim

Arp Axxe Filter Input Broken

Put the VCF RESONANCE slider at MAXIMUM. 2. Monitor pin 10 of the 4023 module with an oscilloscope. 3. Put all other sliders on the front panel DOWN. 4. Adjust the VCF FREQUENCY slider for a sine wave of about 1000 Hz. 5. Measure the peak to peak amplitude of the sine wave on pin 10. 6. Measure the peak to peak amplitude of the sine wave on pin 9 of the 4023 should be about half the amplitude of pin 10 . 7. Adjust the BAL trimmer on Board C until the sine wave on pin 9 is exactly half the...

A V V lTt15

4023 Vcf Schematic

1.4.3 TYPES OF VOLTAGE CONTROLLED FILTERS The 4023 voltage controlled filter is no longer available from the Factory. Instead, the newer 4075 filter can be used to replace the 4023 with the following modification see Field Change Notice 007 The earlier model Odyssey-lls used a 4035 voltage controlled filter, which has since then been replaced by the 4075. No modifications are necessary when replacing a 4035 filter with a 4075. The newer style Odysseys use a zener diode as a noise source instead...