4ms Mesa
Stereo plate reverb with deep modulation and CV over everything
20 HP Eurorack module
Mesa is a stereo plate reverb designed in collaboration with Valley Audio (creators of the Plateau plugin). It runs a Dattorro-style plate algorithm at 96kHz/24-bit on a dedicated DSP, with CV control over every parameter and four phase-offset LFOs for deep chorused modulation. Mesa covers everything from tight ambient slap-back to cathedral-scale tails, frozen drone beds, and even tuned resonator voices when Tuned Size is engaged.
Features
- Stereo Dattorro-style plate reverb (Plateau algorithm, designed with Valley Audio)
- 96kHz / 24-bit DSP
- CV control over every panel parameter (-5V to +5V)
- Four internal phase-offset LFOs with continuously variable shape (saw → triangle → ramp)
- Tuned Size mode: 1V/oct tracking on Size CV for playing the reverb as a tuned resonator
- Freeze button (momentary or latched, mode selectable) for infinite-sustain tails
- Clear button instantly empties the reverb buffer
- Independent Input Filter (pre-tank) and Reverb Filter (in feedback path), each a tilt EQ
- Pre-Delay up to 500ms
- Diffuse Input toggle for transient-preserving slap-back vs smeared plate sound
- Dedicated Clip LEDs at input and output stages
- Bi-color Mod Rate LED indicates LFO rate and direction
Controls & Jacks (36)
- Pre-Delay — Delay inserted between the dry input and the reverb tank, from 0 to 500ms. Adds initial space before the wet signal arrives, useful for sepa
- Dry/Wet — Mixes between the unprocessed dry signal (fully counter-clockwise) and the wet reverb signal (fully clockwise). The red Clip LED above the k
- Input Filter — Tilt filter on the incoming audio before the reverb tank. Center = flat. Counter-clockwise rolls off highs (lowpass), clockwise rolls off lo
- Mod Depth — Amount of LFO modulation applied to the four internal delay sections. Fully CCW = no modulation (static plate); fully CW = deep chorusing an
- Input Level — Input gain trim from -infinity to roughly +3dB. The red Clip LED next to the knob lights when the input stage is approaching clipping. Set s
- Mod Rate — Speed of the four internal LFOs that modulate the reverb's delay lines. Each LFO is phase-offset from the others, producing rich chorus-like
- Mod Rate CV — CV input for Mod Rate. -5V to +5V, sums with the Mod Rate knob position.
- Diffusion — Controls how smeared or diffused the reverb is. Fully CCW leaves audible repeating echoes; fully CW produces a dense, washed-out cloud with
- Decay — Sets how quickly energy bleeds out of the reverb tank. Fully CCW = very short decay; fully CW = a near-infinite, slowly-dying cloud. Combine
- Size CV — CV input for Size. -5V to +5V, sums with the Size knob. When Tuned Size is engaged, this jack tracks 1V/octave so you can play the reverb as
- In L — Left audio input. Max input level approximately +9.6V / -9.6V.
- Out R — Right audio output (dry + wet mix per the Dry/Wet knob).
- Reverb Filter — Tilt filter inside the reverb feedback path. Center = flat. CCW darkens the tail by rolling off highs each loop, CW brightens it by rolling
- Out L — Left audio output (dry + wet mix per the Dry/Wet knob).
- Pre-Delay CV — CV input for Pre-Delay. -5V to +5V, sums with the Pre-Delay knob position.
- Clear LED — Blue LED next to the Clear button. Flashes briefly when Clear is triggered.
- Mod Shape — Continuously morphs the LFO shape across the four modulators: rising saw at fully CCW, triangle at center, falling ramp at fully CW. Differe
- Reverb Filter CV — CV input for Reverb Filter. -5V to +5V, sums with the Reverb Filter knob position.
- Mod Shape CV — CV input for Mod Shape. -5V to +5V, sums with the Mod Shape knob position.
- Decay CV — CV input for Decay. -5V to +5V, sums with the Decay knob position. Excellent for animating tail length with envelopes or LFOs.
- Dry/Wet CV — CV input for Dry/Wet. -5V to +5V, sums with the Dry/Wet knob position.
- In Filt CV — CV input for Input Filter. -5V to +5V, sums with the Input Filter knob position.
- Size — Large center knob controlling overall delay times inside the reverberator, perceptually heard as room size. Fully CCW = very short metallic
- Diffusion CV — CV input for Diffusion. -5V to +5V, sums with the Diffusion knob position.
- In R — Right audio input. Max input level approximately +9.6V / -9.6V.
- Diffuse Input LED — Blue LED indicating Diffuse Input is engaged.
- Mod Depth CV — CV input for Mod Depth. -5V to +5V, sums with the Mod Depth knob position.
- Input Clip LED — Red Clip indicator next to the Input Level knob. Lights when the input stage is clipping.
- Tuned Size LED — Blue LED indicating Tuned Size (1V/oct on Size CV) is engaged.
- Tuned Size — Converts the Size CV input to 1V/octave pitch tracking, so you can play the reverb as a tuned resonator. With Tuned Size engaged, sending a
- Mod Rate LED — Bi-color LED next to the Mod Rate knob. Blinks at the LFO rate; color indicates direction/phase.
- Dry/Wet Clip LED — Red Clip indicator above the Dry/Wet knob. Lights when the output stage clips.
- Freeze — Holds the current reverb tail forever, recirculating audio inside the plate while suppressing new input. Mode-selectable between momentary (
- Freeze LED — Blue LED next to the Freeze button. Lights when freeze is active.
- Clear — Instantly empties the reverb buffer so new echoes can build up cleanly. Adjacent blue LEDs flash when triggered. Useful for gating reverb ta
- Diffuse Input — Engages the input diffusion stage (a pre-tank smearing network). With diffusion on, transients are softened before hitting the plate; with i
How-To Guides
- Master Bus Glue
- Frozen Drone Bed
- Tuned String Voice
- Gated Reverb on Bar Boundaries
- Rhythmic Slapback Echoes
Explore the interactive Mesa panel on BleepDex — tap any control to learn what it does.
