Open Source Hardware

Ladybug LB-202
Portable Mixer

A compact, battery-powered audio mixer built for square dance callers. Works with any powered speaker. Affordable, quiet, and ready for the road.

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Ladybug LB-202 Portable Mixer — front and top view
Click image to enlarge
~$150
Affordable
150 hrs
Battery Life
12.5 oz
Light Weight
−80 dBfs
Noise Floor
Why Ladybug?

Everything you need. Nothing you don't.

Designed from the ground up for beginning and intermediate square dance callers.

🔋

Long Battery Life

Up to 90 hours on a standard 9V alkaline, or 150 hours with a Tenergy lithium. One battery, dozens of dances.

📦

Ultra Portable

6.9″ × 2.5″ × 3.75″ and just 12.5 oz with battery. Slips into any gear bag.

🎙️

Dual Mic Inputs

Two combo inputs accept Lo-Z XLR or Hi-Z Hilton™-compatible ¼″ — great for 2-caller events.

🎵

Dual Music Inputs

Two 1/8″ stereo music inputs, each with its own balance control for quick level matching.

📡

Flexible Outputs

Balanced XLR mono main out, plus a stereo 1/8″ monitor jack (Music L / Voice R) for monitor speakers or hearing assist.

🔓

Fully Open Source

Hardware schematics, firmware, and mechanical drawings are all freely available. Modify the design however you like.

Specifications

Under the hood

Professional-grade specs in a compact, affordable package.

Noise Floor −80 dBfs
Music Bandwidth (±3 dB)20 Hz – 20 kHz
Voice Bandwidth (±3 dB)50 Hz – 20 kHz
Music EQ Bass & Treble controls per channel
Mic EQ Tone control per mic channel
Music Inputs 2× 1/8″ stereo, with per-channel balance control
Mic Inputs 2× Combo (Lo-Z XLR or Hi-Z Hilton™-compatible ¼″)
Remote Volume 20 kΩ Hilton™-compatible 1/8″ plug
Main Output Balanced mono XLR (male)
Monitor Output 1/8″ stereo — Music (L) / Voice (R)
Width 6.9″ (175 mm)
Height 2.5″ (65 mm)
Depth 3.75″ (95 mm)
Weight (with battery)12.5 oz (355 g)
License Open Source Hardware, Software & Mechanical
Battery Type Single 9V
Amazon Basics Alkaline (~$1.50) ~90 hours
Tenergy Lithium (~$6.50) ~150 hours
Typical dances per battery ~30 (alkaline) / ~50 (lithium)
Getting Started

Simple to set up

Add a microphone, a pair of XLR cables, and a powered speaker — and you're ready to call.

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FAQ

Common questions

The LB-202 works with any powered (active) speaker — one with a built-in amplifier. Its balanced XLR output connects directly. Popular choices: Alto TX308 (350W, ~$150) for smaller halls, and Alto TS408 (2000W peak, ~$275) for larger venues.
It depends on your powered speaker. With an Alto TX308 (350W), expect coverage for up to 4 squares. Swap in an Alto TS408 (2000W peak) and you can scale up to 8 squares.
A single 9V battery powers the unit. An Amazon Basics alkaline (~$1.50) provides about 90 hours of use — roughly 30 dances. A Tenergy lithium 9V (~$6.50) extends this to about 150 hours.
Absolutely. The LB-202 has two independent mic inputs (MIC 1 & MIC 2) and two independent music inputs, each with its own volume control. Both callers connect their mic and laptop, and the mixer blends everything to a single balanced output.
Yes — fully open source. Hardware schematics, firmware, and mechanical design files are all freely available so anyone can build, modify, or improve the design. Follow the project at github.com/mpogue2/ladybug-mixer.