I first had the FV-300L. It began to slip after about a year of moderate to light use ( 2 gigs a month ). The warranty had just expired. I purchased the FV-500L because it was updated and the promise was that the slip problem had been addressed. Worked great for 2 years of the same usage and then did the same thing. I really like the pedal. It has a smooth gain and other features set it apart. Unfortunately it is a disposable product. It is not built to last and it always makes more sense to buy a new one than to pay to have it repaired. The quest continues. Also, their service department is staffed by a snotty bunch.

I love this pedal, nice and smooth, and I would like to make a note about the impedance factor. Guitars output a high impedance, and you always want to match the output and next input impedances, HOWEVER, if you run your guitar to another pedal first, THAT pedal (and all other pedals) output LOW IMPEDANCE. So if you want to go into any pedal first (like an overdrive pedal), than this is the right pedal for you. If you want to go straight to the volume pedal, you need high impedance, unless you have active pickups.

Reading the other reviews about this pedal "eating up the tone" and "too big for my pedal-board" it became apparent that people are using this for their guitars. Uhhh, the FV-500L is the LOW IMPEDANCE version - especially designed for use with keyboards and specificaly NOT for guitars. And yes, low impedance WILL kill your tone. That's why guitar inputs on porta-studios (and the like) are labeled "HI-Z". With "Z" being the symbol for impedance.

If you would like to use this pedal for guitar, do yourself favor and buy the one that is made for guitars - that would be the FV-500H (the H is for HIGH impedance).

It's a great pedal. Works super with keyboards - which is what it is made for...but this is not the correct model to use on guitar.

I bought the Boss FV-500L as an expression pedal to work with my Boss PS-5 Super Shifter, as the aluminum casing appeared to be much more durable than the Roland EV-5. The addition of the volume control feature, which can be used either in mono or stereo, also prompted me to chose this product. On the negative side, this pedal is quite large and bulky (11" x 4"), making it unwelcome in certain pedal boards. Additionally, the moving parts of this unit are largely constructed of plastic, making it more prone to damage than its appearance would suggest. Having a cast-aluminum housing means nothing if the most important parts of the unit are plastic! I did have to return the first FV-500L that I purchased, as jolts during shipment were enough to render the unit inoperable. The replacement seems to function quite well, though; and I'm fairly happy with it. If I were to redo my order, I would choose the Alesis F2 volume/expression pedal over this Boss product, however.

Rugged but light. You can adjust the tension for smooth action. Little if any tone coloration. No noise. Minimum volume knob a nice feature. Looks sharp. Passive dual mono I/Os. Mono to stereo operation would require a splitter and buffer amp before the volume pedal. Good pedal.