Wednesday, December 31, 2014

Doepfer A-110-2 Basic VCO Demo

Warning: This is a hardcore technical modular synth post! I recently got my hands on the first copy of a Doepfer A-110-2 Basic VCO Eurorack module that was ever sold worldwide. It showed up at Schneidersladen in Berlin and I was the lucky one, the first one!

Doepfer A-110-2 Basic VCO and friends

The A-110-2 is the follow-up to the A-110-1 which has been selling for many years now. The A-110-2's basic features: Three waveforms (saw, square and triangle), 3-way octave switch, exponential FM (with attenuator), linear FM (without attenuator), pulsewidth modulation (with attenuator), hard and soft sync. It is only 8 units wide which is really cool. I decided to make a demo showcasing the basic and raw oscillator sound as well as two more musical snippets demonstrating various features of the A-110-2. In all examples whenever all three waveforms are presented they appear with their original volume in relation to one another. Warning: The audio files are big! Format: 44.1kHz, 16 Bit mono.

Let's start with the basic waveforms. You are hearing saw, square (50% duty cycle) and triangle in a range of 7.5 octaves. For pitch I used a Doepfer A-145 LFO (triangle waveform) through a Doepfer A-156 quantizer, set to output only 5ths and octaves:


Now let's add some pulse width modulation to the square wave. PWM source is a slowly moving sine wave LFO:


The A-110-2 has a nice feature: Linear FM. In this patch a Doepfer A-171-2 VC Slew Processor serves as the source for the modulation with a frequency modulated sawish triangle waveform. The result is not as dramatic as with Exp FM. Again saw, square and triangle:


Now for exponential FM. Modulation source is the Doepfer A-171-2 with the same configuration as in the Linear FM patch above:


Let's take a look at hard sync. With each of the 3 waveforms (saw, square and triangle) you first hear the A-110-2 slaved to a steady-pitch master oscillator while being pitch-modulated by an EHX 8-step sequencer. After a few seconds I add some LFO modulation via the EXP FM input. You can hear the timbre of the slaved oscillator changing along with the LFO swings:


Now it's soft sync. I must admit that I haven't managed to fully wrap my head around the theoretical implications of soft vs. hard sync. All I can say is that soft sync does not reset the waveform to 0 when the master oscillator finishes a cycle (unlike hard sync) so you won't get any such dramatic changes in timbre as in hard sync. Interestingly modulating the slaved oscillator's frequency does change the perceived pitch as well (again unlike hard sync). Same modulation as in the previous clip:


Now let's go "all in". I have put together two patches that are more musical than the above examples to showcase what the A-110-2 can do if you combine all those nifty features. What you hear in clip 1 is all three waveforms cycled through a Doepfer A-152 quad sequential switch (accounting for some clicking audio glitches here and there) with some random resetting. I have added PWM, Lin FM and Exp FM from various sources as well as hard sync. No filtering, just some amplitude modulation via MFB Megazwerg VCA (AHDSR modulated):


The following patch circumvents the VCA completely. However, there is some amplitude modulation on the saw wave. Later in the clip I start tweaking some of the parameters. Again, no filtering:


I hope I have managed to give you a good overview of the Doepfer A-110-2 basic sound and its most important features. Enjoy the demos!

1 comment:

  1. What a great bunch of demos!!! I have overlooked this module due to the other new modules Doepfer have (and are about to) released. Will have to get one later this year!!!