4ms Mesa: When Reverb Takes Over the Bassline

DivKid first introduces Mesa as a 20HP Eurorack version of Valley Audio’s VCV Rack reverb Plateau. More interesting than its origin is how he handles frozen reverb: a five-step envelope pattern rhythmically fades in the captured cloud. Alongside the original clap, this creates an additional percussion voice. The reverb tail is no longer just an accompaniment to an attack; it becomes the material for new sounds itself.

He then develops the idea further. He lowers the level of a wavetable source, uses Mesa’s input level control to dose individual notes into the freeze, and layers higher notes on top. Two downstream lowpass gates make the held sound playable as percussion. Here, the inconspicuous input level control takes on a musical role: it determines what gets added to the already captured sound.

Metamyther, in “The 4ms/Valley Reverb Mesa Reaches Higher Ground,” also pays attention to practical control details. He highlights the center detent of the dry/wet knob, where both signals are equally strong. Such orientation points are welcome when an effect becomes a playable voice. Not every interesting decision, however, is found in a large knob range.

When switching Diffuse Input, he describes a galloping character without input diffusion, but more smeared contours when the function is activated. DivKid demonstrates the same distinction on Rings: input diffusion softens the attacks, while the separate diffusion knob thickens the reverb itself. For a percussive voice, that’s essential: a softer attack and a denser decay are two different musical decisions.

Holding is only half the story. In the “Mesa Tutorial,” 4ms Company shows a groove from their own sampler, whose start, shaped by a downward envelope, gives the impression of a record speeding up. The same envelope controls Mesa’s size and modulation depth; a gate rhythmically clears the reverb via Clear. Source and space move together, while clearing sets clear breaks.

Clear is more than just turning down the output: according to the manufacturer, the reverb tail is erased and reset. DivKid even gets something he describes as a counter-melody out of it. A quarter-note pulse empties the reverb; depending on which notes fall in between, different ones are briefly sustained. The pauses become part of the composition.

DivKid demonstrates the most striking role change with Tuned Size. According to his explanation, this mode shortens the internal delay times into the audio range and reverses the polarity of the size CV input for normal pitch tracking. A short impulse at the audio input excites this network. Size now sets the tuning, decay the note length, and the reverb filter shapes the sound. More diffusion, in his demonstration, brings in dissonant, metallic components.

DivKid then pursues the bass aspect of this voice: he offsets the pitch sequence downward and varies the strength of the exciting impulses. Little modulation gives vibrato, more diffusion produces the tortured dissonance he explicitly highlights. Then the quarter-note kick and sidechain pumping return. This patch is refreshingly far from any attempt at realistic room simulation.