Dogbotic Workshops
Shaped Dual EnvVCA - 4ms

Shaped Dual EnvVCA - 4ms

by Ellison Wolf

If you’re a fan of envelopes, there’s a pretty good chance—like 99.999%—that 4ms has what you need. With a lineup that includes their classic Pingable Envelope Generator [PEG] and the Mini PEG, their new line of envelope modules covers a lot of bases with the EnvVCA, Dual EnvVCA, and their Shaped Dual EnvVCA.
The Shaped Dual EnvVCA is indisputably the powerhouse of this group, with the most modulation options and opportunities. It’s a two-channel 100% analog envelope generator and slew limiter, with an onboard DC-coupled stereo VCA, and full waveshaping capabilities. The SDEnvVCA sports 4ms’ sleek new-ish black/white look with an elegant facade that makes for an intuitive tour around the landscape, especially when it comes to the ins and outs; inputs are framed in black, outputs in white. Easy peasy. The time range of the envelopes can go from a zippy 2.5kHz all the way down to a leisurely twenty minutes, and with so many input and output options for modulation, SDEnvVCA is beyond multi-function; it’s multi-muti-functional. It can be an envelope follower, LFO, VCO, slew limiter, waveshaper, envelope generator, VCA [x2], and even sidechain processor due to its ducking capabilities. I’m certain I’ll discover even more functions and uses as time goes on. The feature that makes the SDEnvVCA so different from the other 4ms envelope modules is the ability to control the waveshape of each envelope via sliders or CV, all without affecting the timing of the envelope.
Since it’s dual-channel, both CHANNEL A and B are nearly identical. There is a light up CYCLE pushbutton for triggering each channel by hand as well as a TRIG input. A three-position toggle switch determines the behavior of the envelope with CYCLING, an AR response, or an ASR behavior. I really love the inclusion of the ASR option, since the envelope will sustain as long as the input trigger/gate stays high; it brings in a totally different feel that’s completely usable, and not as commonly found on other modules as the CYCLING and AR are. The RISE and FALL slider sections for each channel take center stage here, with LED faders that show the strength and duration of the shape at each stage, and SLOW, MED, and FAST rate toggles for each stage as well. You can really mix and match your rates here to get any feel imaginable, from short snappy percussive shapes, to sleepy, slowly evolving movement.
You can further sculpt the shape with the OFFSET and LEVEL pots and there is a SHAPE slider that can adjust the waveshapes from exponential, to linear, to logarithmic and every point in between. This can also be modulated with external CV, and there is an attenuverter for this as well. I like modulating the SHAPE with a slow moving sine wave to really hear the change taking place, but it was also fun to do with a fast moving square wave synched in time with a melody or kick drum in a patch to throw some accenting in there. Both the RISE and FALL rates can be controlled via a single shared CV input, with each phase having an attenuverter for further control of the shape. Since you can dial in positive or negative amounts of the CV for each, it opens up a lot of options in a small space, and there are LEDs that show the strength and polarity for each stage, which is helpful. The FOLLOW input, which almost gets lost amongst the flashier sections, allows for an input to do some slew limiting and can be used for a ducking effect, envelope following, glide, and much more. Self-patching from one channel into the other makes for interesting modulation opportunities, and having an onboard way to duck/sidechain is pure modular gold, especially for clearing out percussive space in a dense patch.
As mentioned, there is a dual-stereo VCA that is normalled to each channel’s outputted waveshape, but both can be used independently of what the rest of the module is doing, by patching in external CV. The input of VCA A is normalled into the input of VCA B, giving the ability to use both sides of the module with/for one audio input, though some really cool stereo action can happen if you cross-modulate or use a familial TRIG for both channels and use outputs from the same sound source for each VCA input. This is where SDEnvVCA really shines—with these fun, shaped stereo hits where there’s some self-patching going on. The shapes and rhythms that you can get with just this one module and a sound source can be mesmerizing; it’s where I spent most of my initial time, just bouncing around in stereo.
Aside from the VCA outs, there are two ENV outputs that output the waveshape of each channel, and an OR output that emits the highest voltage output of either ENV A or B at any given time. These outputs are directly affected by the LEVEL and OFFSET controls; whereas the other two envelope outputs, the LIN 5V outputs, are not. There is also an end of rise [EOR] output on CHANNEL A’s side, and an output for end of fall [EOF] on CHANNEL B’s side. These are gate outputs that go high any time each respective feature is ending, and remain high until the next stage begins, as indicated by LEDs, and are great for triggering synched up events. With the module’s controls and the CV modulation possibilities, it’s almost like an Etch-a-Sketch for waveshaping, and while there are plenty of ways to get surprises here—so many places to patch CV [whether random or not]—it’s the preciseness of this module that I find most appealing. This is something that 4ms modules excel at overall: they’ve perfected the art of precision in their modules, which I’ve come to have a deep faith in.
One of my favorite things to do was to feed a synched up triangle wave into the SHAPE CV input with the RISE and FALL attenuators pointed full inwards and with the sliders even with each other and about halfway between fast and slow and on the medium setting with the SHAPE being in the exponential position so that the resulting wave would stutter and lurch a bit, like a rollercoaster; then go long on the incline with an extremely sudden drop before being more linear, more even keeled again. It’s this aural anticipation that gets me and feels so satisfying.
Some of the controls, such as the LEVEL pot, are really touchy and there were times when I couldn’t figure out why I was getting sound coming out of the VCA when I thought they should be slammed shut, letting audio squeak by. It was because the LEVEL control wasn’t quite dead center, and there was in fact, some voltage creeping through into the output. What was I saying about precision? Exactly. It’s the reason you can sculpt, shape, and skew waveshapes into so many different formations.
Not that I’m ever looking [I’m usually much too busy losing myself in some addictive patch], but I just can’t find fault with anything 4ms puts out, and SDEnvVCA is one of the most fun playgrounds for envelope shaping that I’ve come across, and have been geeking out with it since putting it in my rack.
20 HP +12v 255mA -12v 230mA
Price: $339