The schematic that I would like to show you are Darlington Power 40V CRATE mean power amplifier for guitar made by SLM Electronics.
CRATE with number GT1200 is gave the audio output for 120 Watts at 4 Ohm load. It’s manufactured at 2000-s.
Table of Contents
SCHEMATIC DARLINGTON POWER 40V CRATE
The image below are result of edit and crop from the original one.
The circuit consists of:
- Preamplifier
- Voltage Amplifier
- Servo Driver
- Over Current Protection
- Darlington Power Amplifier
Preamplifier Q14 and Q20 are using transistors 2N5087. Its using 40 VDC symmetrical supply.
GAIN of the power amplifier are determined by Feedback resistor R65 ( 27K ) with Input resistor R100 ( 330 ).
Q19 ( MJE340 ) are Voltage Amplifier stages of this circuit.
Q12 working as Servo Driver to limit Idle current of Darlington Transistor Amplifier.
Q9 and Q18 are OCP transistor. Any over current at Final Power Transistor, the transistor will short the current to zero and The Final transistor will shut off.
TIP142 and TIP147 are Darlington Final Power amplifiers that can reach maximum power as big as 125 Watts ( DATASHEETS ).
SEE ALSO:
POWER AND MIXER BUILT UP SCHEMATIC ( HERE )
OTHER POWER AMP SCHEMATICS ( LINK )
BLOGSPOT POWER AMPLIFIER ( LINK )
