Here’s a neat little project for audio lovers—a 100W mono HiFi amplifier built using a PCB that fits in your palm. It’s based on the popular 2SC5200 and 2SA1943 transistors, which are known for their solid performance in power amps.
I designed this for clean, punchy output at 4 ohms, with a layout that’s easy to build and doesn’t eat up your workbench space. It's not overly complex, and with some basic soldering skills, you’ll have it up and running in no time.
🔍 Specs & Details
🧠 A Few Notes from My Build
Thick power lines on the board handle high current nicely. No major drops or overheating during tests.
There’s room for a decent heatsink, so don’t worry about cramming things in.
I kept signal lines. short on purpose—less noise, cleaner sound.
Everything fits. pretty snug, but there’s still breathing space for those chunky capacitors and the big transistors.
Honestly, it turned out better than I expected. Good balance between compact and practical.
🔌 Power Supply Tips
You'll need a center-tap transformer that gives you ±35V DC. Something around 3 to 5 amps should be plenty, unless you’re planning to blast music all day.
Oh, and don’t skip the thermal paste or heatsinks. These transistors get hot—protect your build. and your fingers.
🎯 Where It Works Best
🖼️ Want to See the PCB?
🔍 Specs & Details
- Transistors: 2SC5200 (NPN) + 2SA1943 (PNP)
- Channel: Mono (single speaker output)
- Power: 100W RMS @ 4Ω
- Max Power: Can push up to 150W (if cooled well)
- Voltage: Runs best at ±35V DC (can go up to ±45V)
- PCB Size: 80 mm x 50 mm
- Thickness: 1.6 mm
- Height (with parts): Around 35 mm
- Connector Pitch: 5 or 5.08 mm (for screw terminals or headers)
- Transistor Heatsink Gap: 47 mm between mounting holes
🧠 A Few Notes from My Build
Thick power lines on the board handle high current nicely. No major drops or overheating during tests.
There’s room for a decent heatsink, so don’t worry about cramming things in.
I kept signal lines. short on purpose—less noise, cleaner sound.
Everything fits. pretty snug, but there’s still breathing space for those chunky capacitors and the big transistors.
Honestly, it turned out better than I expected. Good balance between compact and practical.
🔌 Power Supply Tips
You'll need a center-tap transformer that gives you ±35V DC. Something around 3 to 5 amps should be plenty, unless you’re planning to blast music all day.
Oh, and don’t skip the thermal paste or heatsinks. These transistors get hot—protect your build. and your fingers.
🎯 Where It Works Best
- DIY speaker amps
- Custom subs
- Tinkering and learning analog audio
🖼️ Want to See the PCB?
.webp "100-watt amplifier PCB, top/front view (component side)")
%20(1).webp "Green circuit board with yellow dots, showcasing a 100-watt PCB layout from the back view.")
Tags:
Mono Amp DIY, HiFi Audio PCB, 2SC5200 2SA1943 Amp, DIY Audio Projects, Custom Amplifier Board
