Sometimes, simple stuff matters. DJ mixers like Pioneer’s DJM-800 have simple, single-knob low- and high-pass filters. Laptop software often doesn’t. Enter FZero, with his free and open source Single Knob Filter to fill the gaps. (Windows-only, built in SynthEdit, but it’s open source and schematics of the basic signal processing are available, if anyone wants to translate this to Mac.) Drop this into an insert in a tool like Ableton Live and go play.

Single Knob Filter [Project Page]
SKF-VST at Google Code [Source, VST Download]

It’s apparently a big improvement on an Ableton forum solution that used 127 different filter instances in a rack.

I’m aware of the goodness of Single Knob Filter thanks to the Aurora open source DJ mixer project (see yesterday’s write-up); they assign an instance of the plug-in on each of the Aurora’s two mixer channels. Aurora’s Matt originally had the SKF plug-in in their Ableton template, but I encouraged them to replace it with Ableton’s Auto Filter for cross-platform compatibility and ease. That said, for plain DJ filtering, this it the One True Knob.

Now, go forth and use it on some crazy experimental noise soundscape you’ve been working on, just to spite cliche.

Not happy with what you can get off the shelf? Build your own. That’s increasingly the philosophy of people working on music hardware. But a second economy is growing around these unique, boutique projects. By open-sourcing the designs, they offer the opportunity to build upon their work, buying something from a small group of designer-musicians and then modifying it to your purposes. The latest addition is the Aurora, which just became available for sale this week. CDM got an exclusive hands-on look at the new hardware and a chat with one of its designers. Here’s our first look at open source hardware’s newest musical gadget.

The Aurora is called a DJ “mixer,” but it’s really a control surface. It connects via a USB jack for power and to transmit serial-over-USB data, then uses free software to translate that data to MIDI messages for use with software like Ableton Live. The project is the work of a three person team, with Matt Aldrich designing electronics, Mike Garbus designing firmware, and Maro Sciacchitano working on the form factor and look and feel. They have an impressive background in making stuff. I got to hang out with Matt in Boston, where he’s joined MIT’s Media Lab Responsive Environments group, so I expect more good projects out of him soon. Matt and I talked frankly over coffee and pastries about the strong suits, weak spots, and future of the device and other projects.

Kit Availability and Pricing

Availability of the first aurora224 model was announced today:

• Complete unit: This kit requires only basic assembly. The PCB is pre-assembled, as are top and bottom panels, and all parts are included. Basically, you just put those panels, boards, knobs, and button caps together using a hex screwdriver — no soldering required. US$340.00. ($420 international)
• DIY kit: This is the one with all the soldering — not recommended if you’re new to soldering, as there’s some tricky stuff in there. US$270. ($350 international.)

Aurora Mixer Project Site
Order Page
Previously: Aurora: Gorgeous, Open Source DJ-Style USB Controller; Details from the Creators

You don’t get that much of a price break via the kit, so I expect you’ll only want to do that if you really enjoy the smell of solder as much as I do.

Onto the hardware itself:

The Aurora 224 is a DJ-style controller geared for software like Ableton Live. The design is, as you can see, gorgeous: not only is it at the high end of aesthetics in open gear, but it celebrates its DIY nature by exposing the circuit board. It’s USB powered, and offers easy mixing control functions in a 2-channel, DJ-oriented layout. And it lights up and makes pretty colors.

Hack a Day broke the story –

Aurora open source hardware mixer

– but to be clear, it’s not actually a mixer; that is, it doesn’t mix audio signal. It’s just a controller in a mixer layout; any mixing and DJ functions are provided by your software. But it is freely-licensed from the ground up, under a Creative Commons license. (We’ve been seeing CC more and more in music projects, as opposed to the narrower and more programmer-oriented GPL and other licenses. There’s no word yet on which CC license applies to this project, whether it has non-commercial or ShareAlike restrictions, etc.; I’ll post an update soon. See discussion on the Virtual Turntable blog.)

A video with Ableton Live, plus CDM chats with the creators about more details: