October 2015 Issue

A summary of this month's contents.

Digital Effects Processor for Guitars and Musical Instruments

This deceptively simple unit offers ten different musical instrument effects including echo, reverb, tremolo, fuzz, compression, flanging and phasing. Each effect is adjustable and can be defeated with an optional foot pedal switch.


Designed for electric guitars but will work with other instruments and vocals too. Optional headphone output and mic pre-amp.  PIC 32MX microcontroller powered, free source code available from our Library.


Surface mount design needs good soldering skills


Opto-Theremin (Part 2)

A 21st Century update on a historic discovery in electronic music making, our latest Opto-Theremin uses light sensors for a manual volume control combined with the original principle of using a vertical radio antenna for pitch control.


By manipulating one’s hands around the sensors, it is possible to produce a very exciting, intriguing and sometimes weird electronic music and sounds. It has a Line Out as well as an integral speaker.


In Part Two this month, assembly details are described.


Surface mount design needs good soldering skills


Courtesy LED Lights Delay for Cars

Designed with older cars in mind, this unit is specially designed to suit LED lamps but also works with conventional filament bulbs. It keeps the car’s interior light illuminated for a preset time after you shut the car doors, and they will be extinguished if the exterior lights or ignition switch are activated during the time-out period. PIC 12F micro powered, free code available from our Library.



After a decade of writing popular articles for our readers we bid farewell to Mike Hibbett who brought the power of the PIC microcontroller to many. We welcome our new PIC expert, Mike O’Keefe who takes over the reins this month with the conclusion of the LPLC Oscilloscope.


Teach-In 2015 (Part 9)


Our penultimate tutorial in the series devoted to discrete linear circuit design looks at classic designs for loudspeakers as loads, amplifier stability, amplifier thermal protection and more. TINA software is used to analyse circuitry. Then the design and construction of a high performance 10W audio power amplifier are described.


Also in this issue:

  • Net Work – Amazon’s acquisition of ‘Top Gear’, Flash vulnerabilities and trends in web site designs
  • Interface - Raspberry Pi and Pulse Width Modulation principles
  • Circuit Surgery – current mirrors and transistor matching explained, and SPICE modelling
  • Audio Out - our enthusiastic audiophile describes some test routines for RIAA equalisation.
  • Max’s Cool Beans  - more on using Tri-Colour LEDs
  • Electronic Building Blocks – adapting cheap and cheerful modules that cost next to nothing online. This month, a 9W stereo amplifier.
  • Techno Talk – the latest trends in solar power.


Next month:

The Currawong 2x10W Stereo Valve Amplifier (Part 1); Programmable Mains Timer with Remote Switching; 48V Dual Phantom Power Supply for DI boxes & Condenser microphones;Teach-In 2015 Part 10: practical measurement, adjustment and faultfinding in power amplifiers. Contents may be subject to last minute change.


EPE is packed with practical electronics projects and theory for the hobbyist. You can order a printed copy of EPE for delivery to your door (worldwide), or try the PDF Version (needs Adobe Reader for Windows), or the Pocketmags for your mobile device. Subscribe now!



Download file

Source code files Guitar FX Unit, Courtesy LED Lights Delay Unit (hex), updated 14/09/15 Theremin templates, Teach-In Part 9. Updated 21/9/15 PIC n MIX Templates 1015.zip


PCB artwork


As from July 2013 issue PCB artwork is available free to subscribers only.


Non-subscribers may purchase artwork files for a nominal sum. Please contact our Orders Dept for information or to place an order.


EPE Printed Circuit Boards


We can supply ready-made printed circuit boards (8-digit order codes) to the original design specification via mail order or from our Online Shop.

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