It looks new. Only been used less than a few hours. Sometimes it only has been opened and tested.

Boss MD-500 Modulation provides 12 modes and 28 different mod effect algorithms, and every one of them has been newly developed specifically for this pedal. All the go-to standards are here: chorus, vibrato, flanger, phaser, tremolo, rotary, classic vibe, and ring mod. Auto wah and touch wah effects are on hand too, plus Boss originals like Slicer and Overtone. Slicer fans will welcome the ability to program custom patterns, an additional feature to the original SL-20 Slicer pedal. And with the MD-500’s spot-on recreation of Roland’s Dimension D from the 1980s, you can add amazing width and depth with one of the most revered studio rack effects of all time.

The MD-500 features 32-bit/96 kHz AD/DA, exceeding all industry standards for pedal-based effects. All internal processing is 32-bit floating point and runs at a 96 kHz sampling rate as well, delivering pristine sonic quality that goes beyond the highest-level digital processors used in top pro studios. And with selectable true-bypass or buffered-bypass operation, you can choose the best setting to suit the needs of any pedalboard setup.

Studio-level sound with first-in-class 32-bit AD/DA, 32-bit floating point processing, and 96 kHz sampling rate

12 modes and 28 modulation types, all with deep editing parameters

Classic mod effects and BOSS originals, newly enhanced with cutting-edge technology

A/B Simul mode for using two patches at once, with your choice of series/parallel connection and mixed or split A/B output

Insert Loop function allows you to use mod effects before, after, or around drive pedals

Graphic LCD and intensive real-time control options

297 onboard patch memories and hands-on controls

Selectable buffered-bypass or true-bypass operation

MIDI I/O for interfacing with MIDI control devices

USB-MIDI for connecting to the MD-500 Editor/Librarian or a DAW

Runs on four AA-size batteries or PSA-series AC adapter

Sampling Frequency: 96 kHz

AD/DA Conversion: 32 bits

Processing: 32-bit floating point

Modes:
12 modes
CHORUS
FLANGER
PHASER
CLASSIC VIBE
VIBRATO
TREMOLO
DIMENSION
RING MOD
ROTARY
FILTER
SLICER
OVERTONE

Memory: 198 (99 banks x 2 [A] [B]), 297 (99 banks x 3 [A] [B] [C])

Nominal Input Level: INPUT A/MONO, B: -10 dBu

Maximum Input Level: INPUT A/MONO, B: +8 dBu

Input Impedance: INPUT A/MONO, B: 1 M ohm

Nominal Output Level: OUTPUT A/MONO, B: -10 dBu

Maximum Output Level: OUTPUT A/MONO, B: +8 dBu

Output Impedance: OUTPUT A/MONO, B: 2 k ohms

Recommended Load Impedance: OUTPUT A/MONO, B: 20 k ohms or greater

Bypass: Buffered bypass or True bypass (with relays)

Controls:
A switch, B switch, TAP/CTL switch
DOWN button, UP button, EXIT button, EDIT button
MODE knob, RATE/VALUE knob, DEPTH knob, E.LEVEL knob, PARAM 1 knob, PARAM 2 knob

Display: Graphic LCD (128 x 64 dots, backlit LCD)

Connectors:
INPUT (A/MONO, B) jacks, OUTPUT (A/MONO, B) jacks: 1/4-inch phone type
CTL 1,2/EXP jack: 1/4-inch TRS phone type
USB COMPUTER port: USB type B
MIDI (IN, OUT) connectors
DC IN jack

Power Supply: Alkaline battery (AA, LR6) x 4, AC adaptor (sold separately)

Current Draw: 225 mA

Expected battery life under continuous use:
Alkaline: Approx. 4.5 hours
* These figures will vary depending on the actual conditions of use.

Accessories:
Owner’s manual
Leaflet “USING THE UNIT SAFELY”
Alkaline battery (AA, LR6) x 4

Width: 170 mm; 6-3/4 inches

Depth: 138 mm; 5-7/16 inches

Height: 62 mm; 2-1/2 inches

Weight (including battery): 1.0 kg; 2 lbs 4 oz