Circuits

A highly modified Linear Feedback Shift Register circuit with a lot of oscillators. Sounds a lot closer to vintage Atari than the much-more-famous Atari Punk Console.

The Atari Punk Console schematic.

A simple circuit that allows for power to be switched between a 9V battery and an AC-DC Adapter. This snippet is useful for the beginning of power supply design for electronics that may need a backup power supply.

A very useful schematic to be used in all sorts of audio applications, including guitar pedal power supply circuits & analog synthesizers. Power is automatically switched from a 9V Battery to AC-DC Adapter, with voltage regulation down to a steady 5V. Includes a 5V voltage regulator, status LED, ON/OFF power switch and output leads.

I took some of my well-earned EE classtime experience and decided to use it for vintage Atari audio awesomeness! This circuit utilizes a Linear Feedback Shift Register along with an adjustable-rate Astable 555 Timer, resulting in Asteroids-like noise.

A quick way to make a flip-flop out of a 555 Timer IC. If your component cabinet is limited, you can avoid having to use two digital logic gates.

One of the most versatile components around, the LM317 Voltage Regulator allows you to power your circuit with voltages ranging from 2.5V to 15V. Try all all of those higher-voltage circuits you’ve been wanting to experiment with! Another great application is simulating voltage sag like an older battery (great for guitar pedals).

In the DIY audio electronics world, getting electricity to power your circuits is merely a matter of connecting the right wires and voltages to the right spots! In this tutorial, I hope that, by the end, you will have a firm grasp on how to make your own**Center Negative power supply.**I will go step-by-step through how to construct a circuit that accepts a Center Negative AC Adapter and/or a 9V battery to supply power to your own circuits. Once the basic circuit has been constructed, I will show you how to modify it: add an ON-OFF switch, add a Power Status LED, and build a 5V voltage regulator circuit for your next breadboard experiment session or DIY design. ...

This circuit is a fork of a great project that I found online while looking for information on Linear Feedback Shift Registers (LFSR). Here’s a video that inspired the fork: The circuit sounds much more like an Atari 2600 than the ever-popular Atari Punk Console, or Stepped Tone Generator for you Forrest Mims fans. While I was not looking to clone the circuit , it did lead me to use it as a base for building one that was little bit more fleshed out. ...

I was hoping to do a quick article on DIY reverse engineering, but was thwarted by a little bit of intellectual property protection! My subject of study was the Rhythm Bandit, a product by Lueken Innovations. I acquired this particular unit from a garage sale for cheap and was not impressed by the rhythm guitar isolation the box promised me. One of the input jacks needed a replacement, so I decided to open it up and take a look under the hood. After unsuccessfully finding screws that typically are used to hold plastic enclosures together, I realized that glue was involved. I drilled a tiny hole with a Dremel and used a screwdriver as a wedge. The glue was holding tight and I noticed something very odd as I pried the case open: the entire circuit was encased in a hard plaster-type material. No small obstacle, but I was determined to find the circuit. I decided to hammer and scrape to get to the circuit board until the circuit was revealed to me. I learned a couple of things about the Rhythm Bandit: 1) No circuit board 2) It’s mostly wiring 3) It’s a very simple circuit (probably a passive RC (Resistor-Capacitor) low pass filter, as it doesn’t require batteries) 4) It was encased in plaster It would probably be close to the truth to assume that the Rhythm Bandit design was “protected” by the plaster so that competitors could not reverse engineer the circuit and to give the box some weight. However, I think that Lueken did this to make a simple circuit appear much more complex than it actually is, and sell it for more. You’d be pretty pissed if you opened up an expensive guitar effect and found that all there was to it was a resistor and a capacitor. Anyway, a passive RC low pass filter costs less than $0.50 to make and gives some decent results. I’ll post one shortly, and then you too can become a Rhythm Bandit! Take a look at the pictures below if you’re curious! ...