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Boss MD-500 review

The ultimate pedal for multiple modulations?

  • £385
  • €398
  • $349

Our Verdict

A powerful machine with a flexibility that’s hard to beat.


  • Comprehensive range of modulation types.
  • A/B Simul mode’s combined effects, practical insert loop, good number of patch memories.


  • The setting up isn’t for all.

We all like a bit of the swirly stuff on our pedalboards and the MD-500 offers it in just about all the guises that guitar players crave. 

There are 12 distinct modulation modes with most having options to select several variations on the theme (there’s 28 algorithms in all). In Chorus mode, for example, you can have chorus unique to the MD-500, the chorus and vibrato sounds from a vintage CE-1 or a 1980s LA sessionman favourite. 

The whole footswitching/patch recall scenario and deep editing capability is the same as the RV-500 but there’s a different set of values assigned to the knobs - as well as the crucial Rate and Depth, you get Parameter 1 and 2 knobs with functions determined separately for each mode. 

Alongside the standard triumverate of Chorus, Flanger and Phaser the MD-500 offers more specialised variations on these themes, notably Dimension simulating Roland’s Dimension D studio rackmount that delivered its own unique spacious sparkle, and Classic Vibe, a tasty Uni-Vibe emulation. 

Incidentally, to answer that question of whether to have fuzz before or after a Uni-Vibe, an insert loop function lets you add another pedal into the MD-500 signal chain and flexible routing saved with a patch allows you to have it before or after the modulation or even between two modulation types in Simul mode. 

You won’t need to insert a dirt pedal for the Rotary effect though as one parameter adds a growly driven-Leslie sound. Smooth amp-style tremolo is on offer but if you want to get more extreme with amplitude modulation there’s the Slicer with its choppy on/off that can be so effectively used with tap tempo. On top of those there’s excellent auto-wah, ring mod and octave effects. 

As individual effects there’s excellent stuff onboard but the fact that you can combine two in A/B Simul mode takes this to a whole new place of creating stunning hybrid effects or just having a different pair of effects instantly available for every song in a set. 

The single pedal supplying a whole range of modulation needs is a very practical genre but some of them are limited to just one effect at a time. That the MD-500 can do two independent effects separately or combined gives it an edge over the close competition: it’s a powerful machine with a flexibility that’s hard to beat.