PotD - Return of the PLL Arabesque

Using a min/max analogue logic module as a phase comparator. Inspired by dougcl's classic PLL patches (1, 2) and this post by Giftnudel.



PLLs seem to be a hot topic again. The jury is still out on whether they're used in the Buchla 259. Make Noise and WMD have announced PLL-equipped VCOs. They form part of the Wogglebug's chaotic heart and can be heard sputtering in the Hertz Donut's bad tracking modes.

I'd read about the inner workings of Doepfer's A-196 and PLLs in general in Horowitz/ Hill's Art of Electronics, but only just tried Giftnudel's patch. The A-196 employs a linear VCO, but as you can hear, the patch works just as well with standard, exponential VCOs:


minmax-pll (master left, slave right)

Two VCOs are compared in a min/max module like the Doepfer A-172. The minimum signal is subtracted from the maximum and the difference fed back to the 'slave' via a slew limiter, thus generating a CV. Depending on the initial frequency difference between the two VCOs and the lag time, you can imitate the wonderful glitches made famous by dougcl.

One nice thing about using this method over traditional sync is that it doesn't affect the sound of the slave as much. The other is that the slew limiter offers control over how well, or poorly, the oscillator tracks.

Basic Electricity #2

Live electronic/ acoustic gig in Berlin, featuring Rastko on Ciat-Lonbarde instruments, Hayden Chisholm on alto sax and Sruti box & Richard Scott on Buchla Thunder.



(Click here for full-size flyer)

Auxxx is proud to present an all-star line-up for the second Basic Electricity night. It takes place on February 24th at 21:00. The venue is the small cinema on Kastanienallee 77, 10435 Berlin-Prenzlauer Berg.


http://rastko.info/

Rastko is a composer and improviser of electronic music based in Geneva, Switzerland. He has been composing music for contemporary dance, theatre and television since 1996. At BE#2 he'll be showcasing the unique Ciat-Lonbarde instruments. A video of him playing the Serge with the CocoQuantus can be found here.


http://haydenchisholm.net/

Hayden Chisholm is a New Zealand saxophonist and composer who has been at the forefront of European music scene for over a decade with his groundbreaking microtonal work and unmistakable sound. At BE#2 he'll be improvising a raga with his 'Well Tempered Sruti Box'. Here is a video of it in action.

Our very own Richard Scott needs little introduction. 'Mr. Wizard-Stix' will be wearing his magic wooly hat, casting sonic spells with his Buchla Thunder/ Wireless Gestural Instrument. You can find some of his recent videos here.

The artists will play a solo and a collaboration.

Basic Electricity #2 promises to be a very exciting night, mixing hands-on circuit manipulation, acoustic improvisation and gestural composition. We look forward to seeing you there!

Patch Tips #21 - Getting Animated

Doepfer's A-137-2 'Wave Multiplier II' does more than just super-saw.



This module uses a set of comparators to generate four 'fake' phase-shifted versions of the input material. The offset of each saw can be modulated, generating a large sound from a single oscillator. As the module is DC-coupled, it can also be used to process CVs.

When I first got the A-137-2, I considered building an expander to gain access to its pulse outputs and avoid having to unscrew the module from the system to remove stages from its output. Two discoveries I've made this week happily mean this isn't necessary.

The first relates to the manual shift knobs: when set at zero, a stage is effectively removed from the output. This is great news if, for example, you only want one additional animated saw. It also has implications when using the A-137-2 as a comparator-based timing delay.

Secondly, the A-137-2 will function without the usual input. Activate a stage by setting its manual shift to something other than zero and feed your signal to its CV input. The result: those hidden pulses! With some careful setting, you can get some mad waveforms:



I'm not sure if this is a bug or a feature - a comparator needs two signals - but, as you can hear from today's Patch of the Day, it offers an additional palette of sounds.



To use the A-137-2 as a shonky beat machine à la A-143-1, feed it a ramp LFO. I've found using a positive-only CV from Maths works best as the comparators switch on both the rising (on) and falling edges (off) of a wave. Patch its output to an A-162 or similar to get clean pulses.

The A-137-2 is another Doepfer gem, offering several uses for not much money. If you want to learn more about the workings of this module, read the ETI article on the Digisound Waveform Multiplier or, if your French is up to it, the Elektor article linked at the bottom of the Doepfer product page.

Audio files not playing

Having moved my content to the cloud, my audio files are once again not playing.

Sugarsync used to allow direct access to files, meaning I could stream my MP3s via the Google reader player. They've now added an intermediary page which means this no longer works. Looks like I'll have to pony-up for a dedicated server after all.

In the meantime, here is a workaround: on Safari, go to a blog post, click play on the player, open up the 'Activity' page (under the 'Window' menu) and look for the Sugarsync URL. Double-click this and it should take you to the download. On Firefox, right-click to 'View Page Source', then search for the Sugarsync link.

Patch of the Day - Highly Strung

Kicking off the new year with the rediscovery of the Doepfer A-137-2 Wave Multiplier and a frenzied take on a duet for two acoustic guitars:



I bought this module when it first came out, then sold it two years ago because I'd run out of space. I've been working on a track that needs a big fuzzy, 'super-saw' bass but wasn't getting the right sound with multiple VCOs and wondered if the A-137-2 might fit the bill. As you can hear from today's PotD, that's not what I ended up using it for: the A-137-2 will do phasing saw sounds, bar the subtle detuning, but I found it's also great for EML-sytle abrasive tones that can then be tamed with a filter.

The patch involves CV-ing the WM II at audio rate, LP filtering the result with the Cwejman MMF-1 and then accentuating various frequencies with a low-bandwidth setting RES-4. Gordon Reid goes into much detail about how to achieve this in his synth secrets, but I just used my ears. A Wiard/ Make Noise Wogglebug generated the timing and note information. It was kicked about by one channel of Maths, which received a mult of the stepped output, thus varying the pace and intensity of the ratchets and completing a timing feedback loop. I recorded two passes of the result, varying the patch by hand.

LeafAudio Noisefoc Samples

A free library of sounds for Ableton's Simpler made with LeafAudio's Noisefoc synth.



From Manu: "We created a free library for Ableton 8 based on sounds of the NOISEFOC Synth - a 3-oscillator synth that can be built in our workshops as a diy-machine. The library includes 16 Simpler-Instruments that show the possibilities of combining diy-machines and professional production. It doesn't sound like that but yes, you can do electro pop with the sounds ;-) All sounds in this song except the drums are made with the Noisefoc library."

Noisefoc Ableton-Library Demosong by LeafAudio

The library is available here. Look out for LeafAudio workshops in Spring 2012 where you can build your own Noisefoc, Fuzz-O-Mat or Bumsss.

4ms PEG Demo

Audio examples of the 4ms Pingable Envelope Generator. An update to this post.



Perfect for synced modulations, the PEG generates LFOs and envelopes which can be locked to a master clock. Once 'pinged', its variable slopes run at either the base time or are stretched/ shrunk to a divided/ multiplied rate. Here it is in action:

4ms PEG demo by navs

The PEG offers voltage control over most of its parameters, various trigger outputs, an analogue OR and a variety of triggering options. The toggle function can be a creative source of surprise, as it flips the activity of the two envelope generators. The curves can be extreme, especially when the skew is maxed in one or the other direction, so you might want to use a linear VCA. That said, a 'whiplash' setting is great with low pass gates.

I've only scratched the surface with this demo: you could try the PEG on drones, slow pans or feeding it to a quantizer for synced, stepped CVs. QNT trig mode allows gated repeats or trills like the Plan B Model 10 or Cwejman CTG-VC. When used with a sequencer, you could set different length envelopes per note, or use the toggle jack to combine the two.

The PEG is rich in possibilities, so make sure you read the extensive manual. Once you've grasped the concept, it's easy to use. If you've ever wanted to keep your wobbles in time, the PEG might be what you've been looking for.