Abusing Doepfer's A-137-2 Wave Multiplier as a quad comparator and event timer.
This had me laughing my head off: the results are just too unpredictable and the patch needs some explaining.
Have a listen first:
The background:
I'm currently attempting to build a quad event timer along the lines of Plan B's Model 17 Triple Event Timer and have so far bread-boarded a working dual comparator using an LM339. This works quite nicely, but is not ideal.
Taking a break and looking for an alternative (read: quick, cheap fix. I'm lazy, right?) I realized my A-137-2 Wave Multiplier is itself a quad comparator. Happily it will accept a DC input, output triggers of a sort and the threshold levels are voltage controllable. Unfortunately it only has a mix out but I overcame this by using a sequential switch to feed a trigger to each envelope generator.
The patch in detail:
Bananalogue VCS paces the A-137-2, A-137-2 mix out to A-151 sequential switch, +5V to its common input is fed to each of the A-143-1 Complex EG's four envelope generators, individual outs to a Cwejman VCA-4MX gating four VCOs, mix out to a CGS52 Lockhart Wave Folder and on to a VCA-2P for panning which is controlled by the mix out of the A-143-1. Still with me? I then took two LFOs (positive and inverted) and patched them to the CV ins of the A-137-2 to modulate the timing of the events.
Two oddities about using the A-137-2 for this sort of application: it's totally imprecise and the input level of the pacing CV has an effect on the timing. You can hear this in the first thirty seconds, where all I am doing is changing the input level. The Lockhart really made this patch for me: when the spacing between events is tight, in effect producing a chord, the wave folder churns out a lovely clangorous noise.
While not as precise as the M17, it's close enough for Rock 'n' Roll and, if it saves me from the soldering iron, then it'll do for now!
Showing posts sorted by relevance for query a-137-2. Sort by date Show all posts
Showing posts sorted by relevance for query a-137-2. Sort by date Show all posts
Wednesday, 28 January 2009
Tuesday, 17 January 2012
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.
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.
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 ...
Wednesday, 11 January 2012
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.
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.
Thursday, 29 January 2009
Algebraic Shift - Patch of the Day Update
A quick update to yesterday's Patch of the Day - Los Comparadores - pressing Doepfer's A-137-2 Wave Multiplier into event timing duties à la Plan B Model 17.
I mailed Dieter Doepfer to ask him whether a modification was possible to allow access to the individual outs of the A-137-2. He pointed me in the direction of this PDF of the module's PCB. I Should have read the product description properly! According to the website, an expander module is in planning and will go into production if there is enough demand. This could provide access to the pulse and saw outputs of each stage as well as toggle switches to take any one of the outputs out of the mix.
In the meantime, I removed the jumpers for all but the first shift unit's saws to test the timing range. Here's the result:
The left channel is the original timing pulse from a ramp LFO, the right is the shifted ramp. Keeping the input level to about 3, the useful delay range seems to be about from 3 to 7. Not bad considering it wasn't intended for this purpose!
I mailed Dieter Doepfer to ask him whether a modification was possible to allow access to the individual outs of the A-137-2. He pointed me in the direction of this PDF of the module's PCB. I Should have read the product description properly! According to the website, an expander module is in planning and will go into production if there is enough demand. This could provide access to the pulse and saw outputs of each stage as well as toggle switches to take any one of the outputs out of the mix.
In the meantime, I removed the jumpers for all but the first shift unit's saws to test the timing range. Here's the result:
The left channel is the original timing pulse from a ramp LFO, the right is the shifted ramp. Keeping the input level to about 3, the useful delay range seems to be about from 3 to 7. Not bad considering it wasn't intended for this purpose!
Friday, 29 March 2013
Super Sawtor Demo
A review of Happy Nerding's Euro-format sawtooth animator.
As the name suggests, the Super Sawtor is designed to produce the sort of multi-oscillator unison sounds known from certain Roland synths and dance genres. Feed it a single saw, triangle or sine to get a dense, buzzing cluster. Too Trance for you? Have a listen:
The two tracks should give you an idea of the Sawtor's sonic scope. If you want to hear more, pay as-you-like to download the source files (10 tracks, @ 25 mins).
The Sawtor is solidly built and simple to use - the only parameters are the dry/ wet mix and the amount of spread. Its internal LFOs change speed in response to the incoming signal's pitch. That keeps the amount of spread even for most of our hearing range. The result is rich, vibrant and less prone to the phase-cancellations I know from my Roland Super Jupiter. Indeed, although it is analogue, the Sawtor emulates the beating of a digital super-saw.
It's this 'intelligent' modulation that sets the Sawtor apart from Doepfer's sawtooth animator and draws a parallel to Cyndustries'. It also limits its use. The only parameter you can affect is the 'spread' i.e. the number of stages. Once activated, the saw-multiples are constantly in motion. They can't be 'stopped' and spaced statically to produce new waveforms as is possible with Doepfer's A-137-2. To improve audio fidelity, the Sawtor is AC-coupled. This rules out certain CV-processing tricks.
So, does that make it a one-trick pony? Yes, but only in the sense that spring reverbs or fuzz boxes are too. Because you can't independently influence the modulation speed, the choice of input becomes important. Gated, sync'd, FM'd or even polyphonic sounds can make interesting fodder if you want to go beyond the Hardcore Hoover. But maybe that is to miss the point of the Super Sawtor: it makes one VCO sound like many and does so without fuss.
Many thanks to Igor for the module and for answering my questions.
As the name suggests, the Super Sawtor is designed to produce the sort of multi-oscillator unison sounds known from certain Roland synths and dance genres. Feed it a single saw, triangle or sine to get a dense, buzzing cluster. Too Trance for you? Have a listen:
The two tracks should give you an idea of the Sawtor's sonic scope. If you want to hear more, pay as-you-like to download the source files (10 tracks, @ 25 mins).
The Sawtor is solidly built and simple to use - the only parameters are the dry/ wet mix and the amount of spread. Its internal LFOs change speed in response to the incoming signal's pitch. That keeps the amount of spread even for most of our hearing range. The result is rich, vibrant and less prone to the phase-cancellations I know from my Roland Super Jupiter. Indeed, although it is analogue, the Sawtor emulates the beating of a digital super-saw.
It's this 'intelligent' modulation that sets the Sawtor apart from Doepfer's sawtooth animator and draws a parallel to Cyndustries'. It also limits its use. The only parameter you can affect is the 'spread' i.e. the number of stages. Once activated, the saw-multiples are constantly in motion. They can't be 'stopped' and spaced statically to produce new waveforms as is possible with Doepfer's A-137-2. To improve audio fidelity, the Sawtor is AC-coupled. This rules out certain CV-processing tricks.
So, does that make it a one-trick pony? Yes, but only in the sense that spring reverbs or fuzz boxes are too. Because you can't independently influence the modulation speed, the choice of input becomes important. Gated, sync'd, FM'd or even polyphonic sounds can make interesting fodder if you want to go beyond the Hardcore Hoover. But maybe that is to miss the point of the Super Sawtor: it makes one VCO sound like many and does so without fuss.
Many thanks to Igor for the module and for answering my questions.
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