The EasyEDA "Tesseract" DIY Guitar Practice Amplifier is an LM386 based low power amplifier designed to deliver up to about 500mW into an
8 Ohm speaker when run from a 9V battery.
- Selectable Bipolar or Junction FET input stage for different input overload effects;
- Adjustable gain and clipping 'hardness' in the Distortion stage;
- An adjustable fullwave rectifier stage, driven by the distortion output, that generates a type of fuzz and frequency doubling effect called 'Wreckage';
- An optional low frequency oscillator stage to sweep the
- A simple mixer to blend the 'Wrecked' and the 'Distortion' outputs;
- Selectable, adjustable low or high frequency boost (a type of tone control);
- An important aspect of the design is that all the features and FX can be tweaked for your delight and delectation.
- Most features are also optional and can be wire linked out if not required without affecting the other functions.
- The design could easily be modified to suit the LM380 2.5W or LM384 5W amplifier chips (although the Boost function would have to be omitted) or a range of other devices.
- The design also includes a headphone output jack.
- The PCB includes dual footprinting to simplify the choice of some of the components.
- All parts (excluding the PCB) are available from: http://www.bitsbox.co.uk/
(Bitsbox can also supply suitable small switches, loudspeakers and battery holders or clips.)
An alternative for J1 as an MPF102 is available from:http://www.tandyonline.co.uk/components/semiconductors/transistors/mpf102-jfet.html
- Simulations of the different stages of this amplifier - and a copy of the EasyEDA LM386EE spice model used in them - can be found here:
- Please note that this project is subject to the CC-BY-NC-SA 3.0 license. For more information please see: