Toppobrillo Matrixplexer
4x4 2D scanning matrix mixer with axis-independent transit modes.
24 HP Eurorack module
The Matrixplexer is a 24HP active 4-input by 4-output matrix mixer with built-in 2D scanning. Each of the 16 cross-points has its own attenuator and a low-noise linear VCA, so any input can be routed to any output (or to several at once) under CV control. Independent X (row) and Y (column) transit engines move the active scan position around the grid using one of three modes (Scan, Stack, Scroll), with shape control over the crossfade slope between channels. A clock input syncs all motion to your patch.
Features
- Active 4x4 cross-point matrix with low-noise linear VCAs at every node
- DC-coupled inputs and outputs (audio and CV both work)
- Per-output hard-mute switches (the four I/O toggles)
- Two independent axes (X = rows, Y = columns) each with their own slider, mode switch, shape, CV input and attenuverter
- Three transit modes per axis: Scan (exclusive), Stack (sequential), Scroll (through-zero LFO)
- Shape control morphs the cross-point crossfade from hard-switch to linear to gate-all
- External clock input syncs all transit motion
- Per-row Row CV inputs gate or offset rows individually
- Per-column Mix CV inputs gate or offset columns individually
- Global MIX CV In sums across all four column scan CVs
- Orange channel-active LED at every cross-point to visualise scan motion
- Through-zero scroll LFOs run in either direction continuously
Controls & Jacks (51)
- MIX CV In
- A Out
- B Out
- C Out
- D Out
- Y-SHP CV In
- CLK In
- A Mix CV In
- B Mix CV In
- C Mix CV In
- Y-SHP
- Y Mode
- Y Mode LED
- Y CV Attenuator
- IN 4
- IN 3
- IN 2
- IN 1
- Row 4 CV In
- Row 3 CV In
- Row 2 CV In
- Row 1 CV In
- A4 Level
- B4 Level
- C4 Level
- D4 Level
- A3 Level
- B3 Level
- C3 Level
- D3 Level
- A2 Level
- B2 Level
- C2 Level
- D2 Level
- A1 Level
- B1 Level
- C1 Level
- D1 Level
- X-SHP CV In
- X-SHP
- X CV Attenuator
- X CV In
- Y CV In
- Mix CVS Mode — Selects how the Mix CV inputs are routed: through (each Mix CV applies only to its labeled output) or summed (all Mix CVs act on every outpu
- A I/O Mode — Selects whether channel A's column acts as an input column (signal flows down through the matrix) or an output column (signals flow into A O
- B I/O Mode — Selects whether channel B's column acts as an input column or an output column.
- C I/O Mode — Selects whether channel C's column acts as an input column or an output column.
- D I/O Mode — Selects whether channel D's column acts as an input column or an output column.
- X Mode — Three-position toggle controlling the X fader's crossfade behavior: stepped (snaps to columns), interpolated (smooth crossfade), or single-c
- X — Horizontal crossfade between matrix columns. Sweeps the active column from A→D continuously (or stepped, per X Mode). Combine with X CV In +
- Y — Vertical crossfade between matrix rows. Sweeps the active row from 1→4 continuously (or stepped, per Y Mode). Combine with Y CV In + Y CV At
How-To Guides
- Static 4-to-4 mix
- Clocked auto-panning
- 2D morph between four mixes
- CV-controlled quad send/returns
- Feedback loop with row gating
Explore the interactive Matrixplexer panel on BleepDex — tap any control to learn what it does.
