Although there are many purpose built panning modules on the market, such as the very excellent Make Noise X-Pan or Verbos Scan and Pan, some might view a specialty module dedicated to panning as a waste of one of our most precious resources: horizontal pitch, or more commonly known as HP. This instinct may be especially true in a smaller case, one with plethora of VCAs, or for someone who likes to patch in more methodical ways, and that instinct would be correct.
Panning is a simple concept. The audio appears to move back and forth in the stereo field creating a sense of motion in space. If done well, this technique of utilizing space can be very effective. In fact, it was a track by the always experimental Ras Thavas which lead me to seek out panning techniques because his use of it was so compelling. With Ras Thavas serving as the destination, I needed a guide. Allen Strange to the rescue, 1 and with a simple patch at that (huzzah!).
If you’re looking to pan a signal back and forth in the stereo field, all you need are an audio signal, a function generator, an inverter, and 2 VCAs. You start the patch by first multing an audio signal and patching each copy to their own individual VCA inputs. Use a function generator (an AD generator works great for this) to create an envelope. Even Attack and Decay (or Rise and Fall) times work best. Send a copy of that envelope to the CV input of VCA 1, while sending the other copy to an inverter en route to the CV input of VCA 2. Turn the gain or bias of VCA 1 to 0 (full CCW), and the gain or bias of VCA 2 to 1 (full CW). Both CV attenuators should be fully CW. This setup will ensure that as the volume rises in one channel, it lowers proportionally in the other channel.
Many envelope generators will output both a positive and negative version of the envelope. A negative output is great for patches like this because it means you can streamline the process and use fewer modules and patch points. In the panning patch above, simply route the negative version directly to the CV input of VCA 2 and eliminate the intermediary inverter.
If you use a cascading VCA, such as the excellent Intellijel Quad VCA, this patch is made even easier. The underlying principals remain the same, but this type of VCA allows you to cut out at least 3 cables and 2 modules from the patch and achieve the same results. Simply send your audio source to a mult and then to Inputs 1 and 2. Next send an envelope to CV Input 1. Turn the CV attenuator to full positive on CV Input 1, and full negative on CV Input 2. The design of the Quad VCA is such that incoming CV normals to the following channel unless something else is patched in to that channel’s CV input. The CV attenuverters do the rest. Be sure to set your bias to full CCW on Ch 1 and full CW on Ch 2.2 Monitor from outputs 1 and 2 as L/R channels.
This panning technique can be further enhanced by substituting a random signal from a stepped random generator or sample and hold. Simply replace the envelope with a random signal, and you’ll end up with pans that put notes in random spots across the stereo field. This method works particularly well with individual notes. Send the same gate or trigger for your note envelope to a mult, and also to your random generator/sample and hold module. Now every note is in a different spot across the stereo field. In Chapter 13 of his book, Allen Strange writes,
Complementary random voltages by means of an inverter produces a unique effect. Since the gain on one channel will constantly be the complement of the other, the sound will appear to move randomly back and forth in the stereo field. The previous patches involved continual motion of the sound on the stereo axis. [One can also] process the control LFO through a Sample/Hold before being applied to the invertor and VCAs. The effect here is that the sound will appear to jump from point to point across the field with each new timing pulse. The sample commands could be at a steady rate from any available timing pulse source, or the timing pulse source could be programmed by a sequencer, random voltage source, etc., to create various panning rhythms. The sampling pulses might also be generated from some external source via an envelope detector.
Other VCAs also have mechanisms that make panning a cinch, such as the Malekko Heavy Industries Quad VCA. Their method uses even fewer cables than the Intellijel VCA, requiring only 1 audio and 1 CV cable. Much like a dedicated panning module, when set up properly the Malekko Quad VCA handles the bulk of the work. They even provide the patch for you on page 6 of the manual.
Panning modules are great. I have of 3 of them (WMD AXYS, Verbos Scan and Pan, and Make Noise X-Pan), and recently ordered another (Metabolic Devices Papomi). But not all of us have the space or cost luxury for a dedicated module for panning, especially when it can be patched so easily, and with such fantastic results. Simply put, you can get great results with the building block tools you probably already have (you do have a function generator, VCA, and an inverter, right?). You don’t need a dedicated module.
**********
1 – All of the patch diagrams in this post were either directly ripped off, or else lightly modified from those found in Chapter 13, “Panning and Sound Location Control”, of Electronic Music Systems, Techniques, and Controls by Allen Strange (1983, reprinted 2022). You really should think about buying a copy. Its contents are proverbial gold.
2 – These settings will create movement starting from the far right of the stereo field to the far left, and back again as long as it’s running. Switch the outputs if you want left to right movement.