more about donuts

The Hertz Donut VCO has become my favorite source of noise and tones. At one moment nice and calm and soulful, the next minute with a few tiny knob-twists or introductions of voltage, it rips your head off. That’s a good thing, and surprising to me since the main reason I like synthesizers is distinctly not for the head-ripping-off that they’re capable of (re: blinky boopity subtractive synths).
I spent an hour the other night working on variations to the church donut sequence I posted previously. The main difference is in the use of the Noisering as the clock source, and to a lesser extent, modulation of the FM index of the Hertz Donut’s second oscillator. These three sequences were outtakes from that hour of recording. On a synth forum I frequent, I was informed by James Cigler that when nothing is plugged into the clock-in jack on t he Noisering, the randomness of the clock is controlled by the EXT RATE knob, which leaks the random signal from the 2nd output into the clock. The EXT RATE knob basically attenuates this signal, allowing for full-on crazy clock, or when turned counter-clockwise, barely any random signal. This is great, and turns the Noisering into a very useful clock source for me. The only problem with it that I see is that the randomness isn’t voltage controlled, and when something is plugged into the CLK IN jack, it breaks the connection. It would be the monkey’s uncle if somehow the source plugged into the CLK IN somehow controlled the amount of that randomness. Instead it’s the other way around, the EXT RATE attenuates whatever signal is plugged into the CLK IN. Both are useful, but I suppose it would take a second jack and knob to make this work.

In any case, this first sequence is the Noisering clock being rate-controlled by a slow LFO sine wave into the CLK IN jack. (When a trigger source is plugged into the CLK IN, that becomes the source of the clock. This merely controls the rate of the internal Noisering clock).

This next one has nothing plugged into the CLK IN jack. About halfway into the sequence I start turning the EXT RATE knob which adds the random signal to the clock.

And this last sequence is longer at eight minutes. It’s also clocked by the Noisering, with some randomness in the signal. In this one there are a lot of different kinds of tones with various modulations being applied to the Hertz Donut and to the Maths, lengthening and shortening the envelope (which for you non synth-heads, means shortening and lengthening the note itself). Near the end the Plan B model 10’s ramp output is all over the second Hertz Donut oscillator, which adds that audible rise in the tone behind the decay of the sound itself. I love that.

All the delay is provided by the Boss DD-3 pedal. It’s convinced me that I need a voltage controlled delay like the Flight of Harmony Sound of Shadows real soon…

how kids draw synthesizers

I recently was asked to drop by the third-grade science class of a local elementary school and show off/explain my modular synth. The class was studying sound and it seemed like a perfect fit. Modulars are graphic, in that they have the shapes of the sound waves printed right there on the VCOs, and they are easy for kids to understand since everything is right there and accessible. This is opposed to, say, digital synthesizers where one knob might do eleven things and everything is hidden beneath multi-layered menus. The visit was a bunch of fun and as I expected the kids just loved pulling cables and turning knobs and hearing the immediate results. I’m sure that the subtleties of the way a four-pole filter resonates vs a vactrol filter was lost on them, but they seem to grasp some of the fundamentals.

In return for my visit, I later received a pack of thank-you cards that the class made. This is one of the perks of visiting schools (which I do often in my “real” job as a children’s book illustrator). Kids love writing and drawing thank-you notes. The cool part of these particular thank-you notes is that many of the students drew modular synths on their cards. Some of the drawings are fairly accurate representations, but most of them are more abstract. It’s wonderful to see what the kids took away from this — matrices of dots and lines representing the knobs, jacks and cables.

So here for your viewing pleasure, I’ve scanned my favorites. I posted a photo of the synth as it looked when I took it to the school at the bottom. Just to show what the kids were looking at.

100215_modular with seq02_006

uLFO

Got a couple of new modules this week. The MFB Dual ADSR will replace the Doepfer A140. It’s got two ADSR envelopes, each with a “hold” state as well as the expected attack, decay, sustain and release. The envelopes can be triggered individually or together, and they each have two outputs. This is all great.
The Bubblesound uLFO is at its heart, as its name suggests, a low frequency oscillator. But it’s more than just that. It can go really really slow — something like 20 minutes per cycle — and it can be tracked at 1v per octave at audio rate, which basically makes it a secondary VCO. I’ve been wanting to learn more about FM synthesis and this is my first module that has a linear FM input. Both of my VCOs, Doepfer A110’s, only have exponential FM (at some soon point I plan to replace the 110s with a Cwejman VCO6 and a Harvestman Hertz Donut but they’re hard to come by right now).

uLFO and MFB dual ADSR

One funny thing about the uLFO. On Monday I noticed that the response of the SIne Shaped output seemed odd. This is a unique feature of the uLFO. It’s got a regular sine output but it’s also got a “shaped” sine, which basically creates what the Bubblesound website calls positive/negative biased non-linear triangles. The wave forms look like waves as drawn by a kid on one side, and bumps or the McDonalds logo on the other. However, I noticed that the shapes it created were the opposite from the icons indicated on the panel of the uLFO. I made a little movie to send to send to Bubblesound to make sure that I was hearing it right.

I posted this to the Muffwiggler forum, which got mixed replies. To make sure I wasn’t going nutty I ran the waves through my CueMix oscilloscope which proved that yes, I was hearing it correctly. Later, David at Bubblesound wrote and confirmed my observation. Regardless of this little quirk, this is a terrific module and I look forward to posting more here from the uLFO.