Clipping indicator is circuit, which signalise with LED when the output of amplifier is in limitation and output transistors are fully open and audio signal is cutted close to power supply voltage. In this case the acoustic signal is distorted in a power amplifier. Sound volume must be set maximally that limitation of amplifier doesn't occure.
Circuit is from pages of author of Leachamp. It was described in an article by Chris Russell in Issue 3 of The Audio Amateur in 1975. I redraw it in a Eagle 5 and I create circuit board for two channels. I added place for two LEDs for power supply voltage indicators. I replace transistors with common types in our region.
Schematics in Eagle5 format: clip2.sch
| quantity | name | value |
|---|---|---|
| 2x | Q1, Q3 | BC639 |
| 2x | Q2, Q4 | BC640 |
| 6x | D1-D6 | 1N4148 |
| 2x | LED1, LED2 | LED 2mm flat face, red |
| 2x | LED3, LED4 | LED 2mm flat face, green |
| 2x | C1, C2 | 10uF/100V |
| 4x | R1, R2, R8, R9 | 12k |
| 4x | R3, R4, R10, R11 | 16k |
| 4x | R5, R6, R12, R13 | 1k5 2W |
| 2x | R7, R14 | 220R |
| 2x | R15, R16 | 22k |
This circuit with older PCB version works great in my Leachamp amplifier.
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