I wanted to build this project a long time ago but I have no time to do it. Today I decide to make a PCB design for it. Unfortunately I do not have any time to make the actual prototype. I will post my design so that anyone can build their own prototype.
About the Circuit
The circuit is not my own design but it is from Eliot Sound Products website. The circuit is published there and if you want more info, you can visit this link: 500W Amplifier from Eliot Sound Products
Here are the published spec from Eliot site:
Figures shown are measured with ±56V nominal, with the figure in (brackets) estimated for ±70V supplies.
| 8Ω | 4Ω | |
| Voltage Gain | 23 (27dB) | 23 (27dB) |
| Power (Continuous) | 153W (240W) | 240W (470W) |
| Peak Power – 10 ms | 185W (250W) | 344W (512W) |
| Peak Power – 5 ms | 185W (272W) | 370W (540W) |
| Input Voltage | 1.3V (2.0V) RMS | 1.3V (2.0V) RMS |
| Noise * | -63dBV (ref. 1V) | -63dBV (ref. 1V) |
| S/N Ratio * | 92dB | 92dB |
| Distortion * | 0.4% | 0.4% |
| Distortion (@ 4W) * | 0.04% (1 KHz) | 0.04% (1 KHz) |
| Distortion (@ 4W) * | 0.07% (10 kHz) | 0.07% (10 kHz) |
| Slew Rate | > 3V/µs | > 3V/µs |
Power Supply
The recommended power supply is +-56V. That can be produced by using a transformer with 40V output. However at this supply, you can only get up to 240W continuous power. If you want to get 500W, you need to supply it with +-70V, you need to use 50V transformer.
PCB Design
Bill Of Materials
| Ref | Value | |
| R1 | 1k | 1/4W resistor |
| R2 | 22k | 1/4W resistor |
| R3 | 10 | 1/4W resistor |
| R4 | 1k | 1/4W resistor |
| R5 | 22k | 1/4W resistor |
| R6 | 560 | 1/4W resistor |
| R7 | 560 | 1/4W resistor |
| R8 | 560 | 1/4W resistor |
| R9 | 1k | 2W Resistor |
| R10 | 22k | 2W Resistor |
| R11 | 3k3 | 1/4W resistor |
| R12 | 3k3 | 1/4W resistor |
| R13 | 220 | 1/4W resistor |
| R14 | 220 | 1/4W resistor |
| R15 | 3R3 | 5W Resistor |
| R16 | 3R3 | 5W Resistor |
| R17 | 0R33 | 5W Resistor |
| R18 | 0R33 | 5W Resistor |
| R19 | 0R33 | 5W Resistor |
| R20 | 0R33 | 5W Resistor |
| R21 | 0R33 | 5W Resistor |
| R22 | 0R33 | 5W Resistor |
| R23 | 0R33 | 5W Resistor |
| R24 | 0R33 | 5W Resistor |
| R25 | 10 | 2W Resistor |
| Ref | Value |
| Q1 | MPSA42 |
| Q2 | MPSA42 |
| Q3 | MPSA42 |
| Q4 | MJE15033 |
| Q5 | MJE15032 |
| Q6 | MJE15033 |
| Q7 | MJL4302A |
| Q8 | MJL4281A |
| Q9 | MJL4281A |
| Q10 | MJL4302A |
| Q11 | MJL4281A |
| Q12 | MJL4302A |
| Q13 | MJL4281A |
| Q14 | MJL4302A |
| Q15 | MJL4281A |
| Q16 | MJL4302A |
| D1 | LED | green 2mm LED |
| D2 | 1N4004 | |
| D3 | 1N4004 |
| Ref | Value | Part | |
| C1 | 10u | 50v | electrolytic capacitor |
| C2 | 100u | 100V | electrolytic capacitor |
| C3 | 100u | 100V | electrolytic capacitor |
| C4 | 0.1u | 100V | Mylar Capacitor |
| C5 | 0.1u | 100V | Mylar Capacitor |
| C6 | 220p | 100V | ceramic capacitor |
| C7 | 0.1u | 100V | Mylar Capacitor |
| C8 | 100u | 100V | electrolytic capacitor |
| C9 | 220p | 100V | ceramic capacitor |
| C10 | 100u | 100V | electrolytic capacitor |
| C11 | 0.1u | 100V | Mylar Capacitor |
DOWNLOADS
You can download the PDF file here: