Simple Guitar Amplifier Using TL071
This general purpose guitar amplifier uses the TL071 IC, which is very cheap and readily available, making it an ideal GCSE project. This circuit is ideal for guitars with low level output from the pickup, as it will amplify it sufficiently for feeding into a power amplifier. It provides voltage gain of around 13, which can be increased to 27 by changing R4 to 100 kΩ. An advantage of this circuit is that it is cheap and easy to make, and it operates on a single power rail, with a PP3 9 V battery. There is also a nice and simple stripboard layout, with minimal cuts and links so you can make a good job of it.
Board Layout
For the stripboard, I am using that cheap one I managed to get, which has 24-tracks × 56-holes. I then simply cut it to the required size.
Here is a view of the board when flipped over along the horizontal axis. This is the view you need when making the cuts to the tracks. There are cuts under C2, IC1, and C4. The rest of the cuts near the mounting holes are optional.
Component List
Type | Part Number | Value | Description |
Resistors | R1 | 56 kΩ | Metal-film, 1/4-watt, 5 % or better |
R2 | 560 kΩ | Metal-film, 1/4-watt, 5 % or better | |
R3 | 560 kΩ | Metal-film, 1/4-watt, 5 % or better | |
R4 | 47 kΩ | Metal-film, 1/4-watt, 5 % or better | |
R5 | 3.9 kΩ | Metal-film, 1/4-watt, 5 % or better | |
Capacitors | C1 | 100 nF | Ceramic |
C2 | 100 nF | Polyester, 5 % or better | |
C3 | 4.7 µF | Electrolytic, 50 V | |
C4 | 10 µF | Electrolytic, 25 V | |
Semiconductors | IC1 | TL071CP | PDIP |
Misc | Switch | SPST | Optional |
24-tracks × 56-holes per track | 14.5 cm × 6.5 cm |
All the components came from eBay and I had enough to make three such amplifier circuits for just less than ten pounds.