The MD-500 includes 12 modes with 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.

For the MD-500, standard effects like chorus, flanger, phaser, and others have been refreshed with BOSS’s advanced new Prime algorithms. Using ultra-fast, high-powered DSP and the latest technology, BOSS engineers have reimagined these essential effects for enhanced expression, extended range, and maximum transparency. With an array of adjustable parameters per type, you have a massive range of sound-shaping potential at your fingers. Some effects even have all-new parameters never seen in BOSS effects before, such as the “Bell” and “Sweetness” settings included in the Prime Chorus algorithm.

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.

The MD-500 is equipped with a large LCD that clearly shows the patch name and other vital performance information. It also makes it easy to view and adjust the unit’s deep editing parameters and advanced control features. With the grab-and-go panel knobs, you have top-level access to essential adjustments like depth and effect level, plus two parameter controls that change dynamically with the selected effect type. And via USB, you can connect with the free MD-500 Editor/Librarian on your computer for remote editing, patch backup, and more.

A/B Simul mode further extends the MD-500’s versatility by letting you run two patches at once. A selectable series or parallel connection enables all sorts of tone-shaping possibilities, and you can even send each effect to its own separate output if you like. The MD-500 also features an external loop that lets you insert gain and drive pedals and set the ideal effect order on a per-patch basis. For example, you can place a phaser or classic vibe before a drive pedal in one patch, and a chorus or flanger after the drive in the next. And when you’re in A/B Simul mode, it’s even possible to position the loop between two different mod effects.

With its freely assignable switches and extensive real-time control support, the MD-500 delivers unmatched expression and performance flexibility. By default, the A, B, and TAP/CTL switches offer control for patch/bank selection and bypass, plus tap tempo or real-time adjustment of one or more parameters. If you like, the switches can be customized to access three different mod patches, A/B Simul mode, and other functions. Via the rear-panel CTL 1,2/EXP jack, you can plug in up to two footswitches for further control, or an expression pedal to adjust wah, effect rate, and other parameters. MIDI I/O is also included, enabling further creative possibilities with advanced setups.

Chorus—Four types: Prime, CE-1 Chorus, CE-1 Vibrato, and TRI-CHO.