Eric Archer, an electronics designer and musician who builds unique electronic sound generators, has posted a collection of samples made using one of his latest projects, the Mini Space Rocker drum machines.

Here’s a preview:

See also our earlier posts on Eric Archer and his Mini Space Rocker drum machines.

Sunday Synth Jam: This is a semi-autonomous synth jam, via Eric Archer:

I’d like to make music free of the cliched compositional motifs I’ve picked up from years of listening to pop tunes in America. Still, I grew up in the 1980s, and the sonic qualities of electro/new wave/industrial are dear to me.

Entertain the notion of playing an “automatic composing machine” that can synthesize sounds like this. The system in this video was built between 2007-09, using 1970’s and 80’s technology. Its analog sounds are controlled by digital algorithms that generate rhythm and melody.

When playing it, my role is to set the tuning, sculpt the tones, and create flow by switching elements in and out of the mix.

This video, from Handmade Music Austin, features a discussion with Eric Archer about his new drum synths and more.

via EA78751:

Handmade Music Austin – a series of DIY music workshops for 2009-2010 presented by Church of the Friendly Ghost.

In a workshop setting, we’ll build a series of miniature electronic instruments called Andromeda Space Rockers. No bigger than a credit card, these projects are designed for DIY’ers. They can be built in a couple of hours to make a working drum machine, bass generator, or micro-synthesizer. These fun little instruments love to jam together, and they do it by forming a wireless network to keep the rhythm!

Of course, there will be an open jam / performance once the instruments are built.

Workshop dates 2009-2010
Location: Austin, Texas October 18 – November 15 – December 20 – January 17 – February 28 – March 14 – April 18

Registration is $45 and includes materials.

Eric Archer demos four tiny drum machines with analog sound, IR wireless network, and photocell control.

One drum is running through a DigiTech Synth Wah pedal. The other three are mixed dry. The mix is playing through a guitar amp.

See the recent post on minimal drum machines for more info.

This is a video demo of Eric Archer’s Minimal Drum Machines – a DIY preset beatmaker that can communicate wirelessly with other minimal drum machines, sync and create more complex rhythms.

Details below.

via EA78751:

I’m testing the definition of “drum machine” with these fun little prototypes. They have only two chips, (TL06x opamp and CD4089). No microcontroller. One knob (tempo). One button (reset). Sixteen rhythm presets on a DIP switch. Light reactive circuits to bend the sound.

Even though the machines can play alone, they’d rather play in a group. Thats because each machine has an infrared transmitter and receiver. This lets them form a wireless network to play at the same tempo. The IR link is limited to about 12? and does not work under bright incandescent light. (the video was shot with compact fluorescent)

At the end of the video I show how interrupting the IR link affects the sound. In theory, many of these machines could be networked.

Both machines in the video share the same sequencer design. It is based on the CD4089 binary rate multiplier. Their sounds are different though. The unit in the foreground uses a pair of bridged-T oscillators to make clave / rimshot / bongo sounds. The unit in the back generates filtered noise bursts with a classic “swing VCA” mechanism.

Once finalized the designs are intended for use in a fun educational workshop setting.

Image: ALH84001

Eric Archer’s Drone Commander is a $325 portable synthesizer housed in an awesome Riot Control Agent box.

With a total of 9 knobs, the Drone Commander offers two manually-tuned oscillators and two LFOs, plus an unusually colorful and nasty filter. LFO1 is an analog variable-shape oscillator, and LFO2 is a pulse waveform that auto-synchronizes to LFO1 at a ratio of 2x, 4x, 8x, or 16x. Both LFOs can be routed to the filter for rhythmic patterns. A line-level output jack is provided for connection to amplifiers or effects.

Six of the Drone Commander’s nine knobs double as push-pull switches to control signal routing and waveform selection.

The Drone Commander is housed in a dark green military ammunition case with engraved aluminum control panel. The case is welded steel with an easily removable, rubber gasketed lid.

The unit is powered by a 9V battery accessible through a slide-out drawer in the side, as well as a 9VDC adapter.

You can preview the sound of Drone Commander below:

Details at Archer’s site.

via the Synthtopia Flickr Group

Eric Archer’s Light2Sound is a DIY project that lets you create a synthesizer that turns light into sound:

The pickup is a photodiode on 8? flexible cable. It connects to LITE2SOUND with an RCA plug. Its detachable so you can experiment with making your own pickups – just cut an RCA cable, strip the cut end, and solder a photodiode to the leads.

To hear LITE2SOUND, plug it in to a guitar amp, effect pedal, mixer, or the mic input of a recording device.

LITE2SOUND reveals unusual sounds. For instance, pointing it at a computer CRT yields a strange humming tone that varies depending on what the screen is displaying. The LED in an optical computer mouse plays strange chirping whistles. Infrared remote controls make wild bursts of noisy data. You’re hearing frequencies from lines of code executing in a microprocessor… stuff that was never intended to be heard. When you combine LITE2SOUND with a laser pointer, things get really interesting. There is bizarre audio from a vinyl record as it spins on the turntable, using a laser instead of the needle. Listening to reflected laser light as you move it over the surface texture of objects is often a surprise; it plays the texture like a phonograph needle. You can even pick up unusual sounds from a guitar string as the laser reflects off of it. There are still many things to try…

Kits start at $55. Details and audio demos are available at Archer’s site.

Eric Archer has come up with a new music sequencer based on the Fibonacci sequence.

Here are the details behind it:

Fans of the Golden Ratio know that it is built-in to the Fibonacci Sequence, being the ratio of S(n)/S(n-1) when n is very large.

But lets make it more complicated.

The Lagged Fibonacci Generator is a generalized version that looks at a wider “history window”; instead of the two previous numbers, it lets you go back farther in the list with parameters j and k.

S(n) = S(n-j) + S(n-k)

These numbers are limited to whatever bit depth you choose to represent them. Whenever the addition generates a “carry”, it rolls over at zero again and outputs a carry flag. For example, if you’re using 8 bits, the m value is 2^8, or 256. What happens then is magic because instead of an ever-increasing string of numbers, you get a set of numbers that hop around back and forth between zero and m. The complexity of the sequence grows rapidly with larger j and k values, but its never random or chaotic.

Here’s the details on Archer’s demo video, above:

Here is an excerpt from my unreleased videotape “Thirteen Meditations on the Meaning of the Tao”.

The patterns are synthesized with a Lagged Fibonacci Generator (LFG) circuit built with discrete logic chips (CD4000 CMOS). The LFG is an algorithm sometimes used in cryptography to generate encryption keys.

I’m exploring it as a pattern generator for algorithmic art and music.

Although cryptographers like the LFG because its output is similar to white noise, I find that through creative electronic filtering, the intricate details of its cyclic patterns become visible, and we can appreciate the details.

Digital patterns from the LFG are converted to two analog outputs with separate hardware of my design. These analog waveforms were processed through an Electrix Filter Queen resonant filter, and visualized on a high resolution Tektronix X-Y monitor. The video was recorded to VHS with a camera pointed at the screen. The audio was recorded directly, and contains the same waveforms being displayed.

via EA78751, Make

Eric Archer’s ABot (Another Box o’ Techno) is an interesting collection of DIY experimental synth circuitry. 

It features:

• Dual VCO w/ digital sub-bass sinewave
• 12dB/oct VCF
• SyncLFO
• LFO-Sequencer
• WaveFucker (1-bit pitch shifter)
• Analog-controlled speech synthesizer
• Generative CV sequencer for melody control

The ABot synchronizes with Archer’s BBoT (Big Box o’ Techno).

Continuing with Archer’s BBoT ethos, there is no computer interface, storage, MIDI, etc.  Improvisation is the only approach. There is no alternative.

You can preview the ABoT sound below.

Speaker Warning: Massive bass ahead.