Hobby-Circuits (Page 2)

This is a Analogue Synthesizer Controller from The Peasant. It Aims to be an extremely versatile Musical Effects Equipment working with he “SynthCase System” which also can be found there.

SynthBend – The Electronic Peasant

SynthBend - The Electronic Peasant

Some of you may be aware of my Electronics Engineering community. A DIY question was asked by a young person …

“I wish to build a modular style analogue synthesizer . I was wondering if anyone had any relevant circuit diagrams for oscillators, filters or amps etc …..Im really interested in building good circuits but in my own design ?”.

This made me add some of the Analog Synth Enthusiast Sites in this blog. I also realized that this is a good starting point for young minds to learn analog design. If a student or hobby learner is enthusiastic about some idea, he gets the drive to learn the basics on his own.

When a person who is learning, or even a professional, is passionate about what he is doing; he achieves what is called as Resonance in that filed of activity. This is when Innovations Sparks, this is when an Invention Manifests. This is the beginning of R&D.

Getting back to The Peasant in his own words about this device he created …

“A classic control-voltage type keyboard and an Appendage ribbon controller would be the heart of the project, with many added features. A large quantity and variety of manual CV modulation controls, such as joysticks, potentiometers, and pressure sensors would also be included.”

Gainclone or chipamp is a type of audio amplifier made by do-it-yourselfers, or individuals interested in DIY audio. It is a design based on high-power integrated circuits, particularly the National Semiconductor Overture series.

GainClone Chipamp Audio Amplifier

The Gainclone is probably the most commonly built and well-known amplifier project amongst hobbyists. It is simple to build and involves only a few readily accessible, inexpensive parts. As an amplifier it is highly regarded by many in the DIY community.

GainClone Amplifier Rod Elliott (ESP)

“The amp is based on the Project 19 PCB, so uses a pair of LM3876 (or LM3886) power opamps, run from a ±35V supply. ………..The power supply is conventional in almost all respects. I used a 160VA transformer, a 400V 35A bridge rectifier, and a total of 20,000uF per supply rail – 4 x 10,000uF caps in all.”

GainClone Chipamp Audio Amplifier

“The Gainclone amplifier has proved very popular with hobbyists since construction is straightforward and the resulting amplifier has an impressive performance specification.

A Gainclone for the PC Age

Most designs discussed online are aimed at audiophile applications. Here is a design for connection the a PC. It powers up and down with the PC and audio input can optionally be taken over USB.”

Gainclone Monoblocks

“But it was the Gaincard that caught the imagination of audio diy-ers around the world and before long, copies of the Gaincard were appearing on internet sites and discussion forums. The Gainclone was born!”

incise.org: gainclone

“I had previously planned to build a small stereo amp using the amp6 kit from 41hz.com. After deciding I wanted a bit more power, I did some research and am now going to build a so-called gainclone amp based on the LM3886 chip.”

“First, check out this 3-channel buffer amp Darcy made! It uses the chipamp.com LM3886 amp boards! Feel free to send pictures of your amp and we’ll show them off for you.”

This is a educative and simple example to help learn about supercaps and white LED. It will also help you understand component behavior. If you are learning electronics, try this one out.

The goldcap-Dynamo Lamp idea is a DIY Tutorial by Kainka on Electrical Energy Harvesting. What may be this EH Thing ?

Supercap and White LED and Energy Harvesters

Energy harvesting (also known as power harvesting or energy scavenging) is the process by which energy is derived from external sources (e.g., solar power, thermal energy, wind energy, salinity gradients, and kinetic energy), captured, and stored for small, wireless autonomous devices, like those used in wearable electronics and wireless sensor networks. – EH at Wikipedia

Then the Cycle Dynamo may not be the ideal choice for furthering this research. The reason being, this is quite a powerful source of energy, especially when going downhill!

Electric Double Layer Capacitor – EDLC

We need a more fussy source of Electricity. Like the waves of the sea, that could splash onto Large plates of Springy Beryllium Copper Cantilevers, which moves an Array of Magnets in coils (Reverse of Solenoids). This gives Random Spurts of High Energy Pulses which have to be Harvested.

Piezoelectric Energy Harvester – Mide Technology

That is for you to dare and do …….. Now let me give some things you can read, before you start this epic Adventure…

Electric double layer capacitor an eFlywheel

Now Move ! There is so much Abundant Energy to be Harvested. You can Even Setup a Roadside Electric Trike Recharging Station. – Gomier Electric Tricycle

We need more contests, An LED Lighting Contest and a Sponsored Elekrik Vehicle (Non-Car) Super-Contest.

This was made by me when i was a kid, it was even published in a magazine, i think it will work, it was used on a very old huge ornamental valve philips stereo system in the remote speakers.

Recently i captured this circuit in eagle to publish online, it seems to have a small design error. It worked well for many years. The step-down transformer is used as a step-up here. The secondary winding was around 50mA so the resistance was protecting the 2N2222. (SL100 was used in the original one). C1 and R3 may need tweaking to get the desired adjustment range in R2.

The voltage across the speaker is fed to C1-Gnd, which blocks DC component. R1, R2, R3 form a threshold bias for T1. 2N2222 chops the 12V DC in tune with the music. The chopped DC current flowing in the 12V winding of TR1 is stepped up into AC pulses over 100V, this lights the Neon in flashes synchronizing in real-time with the beats. Known Issues – It does not perform well at low Bass like 20Hz.

Music Sound to light converter

The Source file in CadSoft EAGLE format is here del00005.zip

Here are many Audio Effects and Music DIY electronics Articles with Schematics and idea behind the concept. Electronic Music Enthusiasts will find these useful for learning.

Runoffgroove – DIY Articles and Schematics

Some Entertaining Projects are –

Mr. EQ – A simple, yet potent DIY equalizer. Schematic, PCB/perfboard layouts, and photos.

Little Gem – Two 9v battery-powered amps based on the LM386. Schematic and PCB/perfboard layouts.

Eighteen – The Marshall 18W adapted for use as a distortion stompbox. Schematic, PCB/perfboard layouts, and photos.

Tonemender – An ultra-flexible tonestack with clean boost. Schematic, photo, and PCB/perfboard layouts.

Thor – The legendary Marshall 100W Super Lead adapted for use as a distortion stompbox. Schematic and PCB layout.

The Thunderchief project, released in March 2004, was the first runoffgroove.com circuit that was developed using the tubes-to-FETs process. Enlightened and inspired by Doug Hammond’s excellent Meteor circuit, we used the same approach in an effort to capture some of the legendary magic of the Marshall Super Lead. The circuit’s performance pleased us, but there were issues.


Splitter-Blend – Dual parallel buffered effect loops with blend control. Schematic and perfboard/PCB layouts.

Professor Tweed – The Fender Princeton adapted for use as a distortion stompbox. Schematic, PCB/perfboard layouts, and photos.