Skip to main content

A-137 Wave Multiplier

I might have underrated the A-137-1 Voltage Controlled Wave Multiplier a bit. Until lately...

The basic idea of a wave multiplier is to multiply the waveform of an incoming signal and add harmonics to a signal that contains none or only a few harmonics (e.g. sine or triangle waveform)
The A-137 can be used with signals rich in harmonics too (e.g. saw) but the effect is not as remarkable as for triangle or sine waves.
For rectangle signals none or only little effects are obtained.

The A-137 is a very interesting module, in a way it is quite similar to the A-136 Distortion/Waveshaper
You can compare it with four simple A136 modules in series. (The A136 is basically like a guitar distortion stompbox with different distortion levels for the positive and the negative parts of the signal.)
Only in this module you do not have separate access to the two half waves and to the parameters of the individual stages.

The parameters of the A-137 are:
- Multiples: defines the number of basic wave multiplications within one period.
- Folding Level and Symmetry: the upper and lower clipping levels of the wave folder units are controlled.
- Harmonics: adds some harmonic content by sharpening the waveform edges and adding overshoot peaks. It works a little bit like the resonance control of a VCF.

All 4 parameters can be manually adjusted and controlled by external voltages.
It is a lot of fun to experiment with this module, with all different parameters controlled by different CV sources like LFO, ADSR's, Ribbon Control pressure and sequenced triggers for example.

The only thing i dislike about this module is the unpredictability factor.
You should be carefull for a 'damping' effect that can occur when different parameters interact with eachother.
But on the other hand; the module is fully DC coupled, so even CV signals can be messed up with this module.

Check out the audio examples on the Doepfer site that explain the function of the module and its parameters.

Popular posts from this blog

DIY Modular Case Ideas

There are many ways to house your (eurorack) modular synth, i wrote about the pre-manufactured options from Doepfer earlier, find that post HERE, but of course you can also try to build you own case.
There are many ways to make your own A-100/Eurorack case if you start out with just the basic rails and busboard, and you can make it as cheap or expensive as you can.

Check out a few ideas;
Wooden cabinets and side-panels are still very popular amongst (modular) synth enthusiasts.
These simple case standards for the pre-manufactured LC9 cases are very simple, and can be sooo useful
http://synthesizerart.blogspot.com/2011/10/dual-doepfer-lc9-case-stand-v1-design.html Also check out the other great modular pictures on his site.
Matthew Goike (@Goiks) also has some nice wooden cabinets on display and for sale on his website: http://www.goike.com/node/5

...or do what Stretta did (or rather what his brother did), make a high-end wood/brushed aluminium cabinet with integrated LED-lights and some …

Doepfer A-150-8 Octal Manual/Voltage Controlled Programmable Switches Announced

Doepfer has just released some info on their new modules for NAMM 2017 (19-21 jan.) Besides some vintage editions of existing modules, the A-135ABC VC Performance mixer modules, the A-110-6Trapezoid Thru Zero Quadrature VCO and a new A-100LC1 case (economically priced small housing with 48 HP width) there was also one other interesting new module announcement:
Module A-150-8 contains eight manually/voltage controlled switches.  Each of the eight switches has a manual control button (Man.), a control voltage input (CV), a common Out / Input (O/I), and two In / Outputs (I/O1, I/O2).  The switches are bi-directional, i.e. they can work in both directions, so can connect one input to either of two outputs, or either of two inputs to one output. 
Two LEDs show which in / output is active (ie. which is connected to the common out / input).  In addition the LEDs are used for the programming of the module: For each unit the operating mode can be selected:  Toggle or Level controlled. In Toggl…

Happy New Year From PatchPierre

Hi there, it's me again... Happy New Year!

You might have noticed that I havent posted a lot in the last 2 years...
It's been a rough time for me since the sudden loss of two parents within a relatively short time-span and I really needed some time to get myself together... to set things straight, finding myself and selecting priorities... even my regular work suffered from this breakdown.

It took a while to understand it all, and to get a better grip on it, and it's sometimes still not very clear.
I think I have found a way to cope with most of it now... although the slight autism that I have (ADD-like) doesn't make it easy for, especially in crowds with lots of people I don't know...
On my journey I also (re-)discovered the beautiful woman that has always lived inside of me and that i need to accept and cherish... more on that maybe later... I'm not considering changing the name of the blog to PatchPetra.Net 😇 (...yet), but you might spot me somewhere at mod…