Acid Rain Maestro (Discontinued)

Six-channel Eurorack modulation controller with SD card preset storage and real-time performance features

Overview

The Acid Rain Maestro Performance CV Generator is a 20hp Eurorack module made by Acid Rain Technology. It functions as a clocked modulation controller with six independent channels, each capable of looping or one-shot modulation waveforms. Designed for live performance, it allows real-time control via buttons to switch waveforms, chains, and modes without breaking sync. The module is inspired by automation lanes in digital audio workstation software and supports internal or external clocking.

Specifications

Model	MAESTRO
Width	20hp
Depth	25mm
Current Draw	65mA @ +12V, 18mA @ -12V
Power Consumption	+12V: 65 mA, -12V: 18 mA, 5V: 0 mA
Voltage Output Ranges	0–5V or -5 to +5V (bipolar operation)
Channels	6
Waveform Modulators	8
Modifiers	2
Preset Storage	Save up to 14 preset states to SD card
Original Price	$399.00 USD

Design

The Maestro features a performance-oriented interface where nearly every function can be adjusted in real time with minimal button presses. It generates multiple modulation types including LFO shapes and random voltages, each with time multipliers, divisors, smoothing, and bi/unipolar options. Waveforms can be chained sequentially for evolving modulations or rhythmic patterns. A synchronized clock system tracks elapsed pulses from reset and maintains phase coherence across all six channel outputs, even during manual waveform switching. Each channel supports live-switchable looping or one-shot modes, and any channel can become a complex CV source via the One Shot function. Presets are saved to and loaded from a uSD card, with recallable slots cached in internal memory.

Context

The Maestro is part of Acid Rain Technology’s modular lineup, which includes Chainsaw, Navigator, Junction, and Switchblade. It shares the brand’s focus on performance-centric clocked modulation tools.

Market

The Maestro was originally priced at $399.00 USD. A used unit in "Excellent" condition was listed for sale at a price of $347. Demo units were available for $359. The module is discontinued, as noted on Modulargrid.