Messrs. Schmitt, Trigger and APC (and other stories)


Just for the hell of it, I wondered if it was possible to substitute the 555 timers in an Atari Punk Console (APC) with some other component, or components.

After seeing some Schmitt-trigger inverters (CD40106) used in oscillator circuits, see Swingers, I thought that I would come up with an alternative design.

Continue reading Messrs. Schmitt, Trigger and APC (and other stories)


555 Noisemusick kit


A friend of mine sent me details of the 555 Noisemusick kit, which, while it looks like an Atari Punk Console (APC) – see Atari Punx… -it is essentially two astable multivibrators, with the first providing a CV input to the second, and with additional IR sensors and touch pads.

It is also available as an iOS app, source code is available on github:Noisemusick.

Continue reading 555 Noisemusick kit

Sequence Dancing


Following on from Atari Punx…, which was my first foray into the world of electronic sound generation, it seemed that a sequencer is a very useful piece of additional kit. One can be easily made using a CD4017 decade counter (or CD4022 octal counter)… However, other ICs can be used, to provide additional functionality. For example, a CD4510/CD4516 BCD/Binary counter and a decoder or 16 channel multiplexer, such as a CD4028 or CD4067, can add up/down sequencing, pre-loading and other features.

Let’s take a look at all of these ICs as well as some others.

VCO, VCF and VCA circuits are also touched upon, be are covered more fully in Banging noises…

Continue reading Sequence Dancing

Atari Punx…


A friend of mine, Pavel, from the group Bang Sue Electrix, told me about the Atari Punk Sound generator. I’d never heard of it before, and I initially thought that he wanted to re-create either an old Atari VCS games console, or Atari 800 PC. When he showed me the Wikipedia – Atari Punk Console page, I realised that he was actually referring to a Stepped Tone Generator, formed from an astable square wave oscillator driving a monostable oscillator, (or – if you prefer – an astable multivibrator circuit triggering a monostable multivibrator circuit) which uses two 555 timers (or a single 556 timer IC)…


Reminiscent of vintage Atari video games, the synthesizer’s output is a characteristic Forrest Mims, a popular electronics author, published the original Atari Punk Console schematic for a “Sound Synthesizer” in Engineer’s Notebook: Integrated Circuit Applications   and then a “Stepped Tone Generator” in Engineer’s Mini-Notebook: 555 Circuits.  Kaustic Machines took the circuit and popularized their version as the “Atari Punk Console”.

This article looks at a the basic Atari Punk Console design, and then some variations, and improvements, upon the original design. Finally, it takes a look at replacing the 555 timers with some other multivibrators based around Schmitt triggers, BJT relaxation oscillator, and the oscillator taken from a Stylophone.

This article also takes a look at some unrelated 4069 musical projects…

See also Banging noises… and Sequence Dancing.

Continue reading Atari Punx…