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.