Sunday, 21 December 2008

Doepfer A-137-2 Wave Multiplier II Demo



A quick demo of Doepfer's A-137-2 Wave Multiplier II.

The module uses comparators to generate four phase-shifted copies of the incoming signal to provide a robust, multi-oscillator type sound. Think 'super-saw' without any of the phase cancellation issues usually associated with mixing multiple VCOs.

In the first example you'll first hear the source saw, then the A-137-2 and lastly three VCOs.



The next clip shows that the input level clearly plays a role in the resulting sound. At the beginning you can hear the comparators struggling to lock-on. I found the sound to be most pleasing around the '7' mark.



You can get some very nice effects if you have tempo-sync'd LFOs. In this example I used two S&H outputs of my Kenton Pro 2000 II.



This shows what happens when you feed the A-137-2 with a sine and then a triangle (it won't work with pulses). A nice buzzy sound, but not quite the same as mixing multiple sines or triangles.



And finally, a short demo of what two 'five-VCO' parts can sound like in the mix. Apologies to 808 State ...

7 comments:

Anonymous said...

very cool. So for instance the first demo, are you using any modulation on that? I'm wondering whether it'll do its thing without a bunch of LFO hogging.

Navs said...

Cheers! You can set the four offsets manually, but to get the most out of it you'll need LFOs, envelopes or random CVs. I fed it with the outputs of my Cwejman VCO-2RM in LFO mode (2 +ve, 2 -ve) or for tempo sync'd modulation, two LFOs from my Kenton which I fed to two inverters to get +/-ve modulation.

Göran Sandström said...

Hey, I've been thinking, can you use it to create like quadrature-ish slow randoms? Or is the input ac-coupled?

Navs said...

Hi Göran - sorry for the late response! The input seems to be dc-coupled as it will react to an LFO, so feeding it a random should be possible. The problem would be tapping the quad-outputs: you would have to build an expander to access the individual outs, cos the stock A-137-2 has just one 'mix' out. I mailed Dieter Doepfer about this and he said it should be easy: the individual pins exist on the board. The only warning he gave me was to use some resistors on the outputs as they are 20Vpp! The product page mentions they would consider building and selling the expander if there was enough demand.

Elan Hickler said...

I would love to hear the demos, but when I press play on any of them, they do nothing. Play button becomes a pause button... that's it :(

drip.feed said...

Where did the audio files go, Nav? :(

Navs said...

Google have canned Reader, so I'm going to have to re-link all files. Again! In the meantime, mail me for specific files.