MXR Phase 90 pedal is a small analog stomp box (foot pedal) made of hard steel casing, with a 1/4 jack going in (from instrument) to output. There is one knob marked speed. This of course is the design, but older boxes will sound different from newer ones. My pedal is from early 2000's and is probably very similar to ones you will find for sale tody. The side of the pedal has a housing for a common 9V plug or battery will do; this pedal is one of the few that has never given me any powering problems.

This pedal is a pantheon in rock music. Chances are your favorite rock music is laden with phase pedal effects. For example, Led Zeppelin's "Ten Years Gone" -- that first hard rock lick in the beginning, there's some serious phase. Phase is excellent for most instruments, especially bass guitar, electric guitar, keyboards, even voice (probably from a rack module, though, unless your singer wants it live). As you can tell, phase is used when you want to add a 'washy' or 'warbly' tone. The box grabs the incoming tone and 'phases' the wave at a different rate and tone then feeds it out. The speed can make it seem very gradually whooshing or high speed for a sound similar to when you hum and tap your adam's apple. And for good entry level and pro type phase, in my opinion, this is an absolute must. These are the pedals Eddie Van Halen somehow turned into an incredible tonal fury. For funk, reggae, R&B, uptempo grooving and rhythm, this pedal is simply unbeatable. Try a Les Paul with the tone high on the neck pickup, phase it out at about half-way on the speed dial, and try a couple of 'bob marley' rhythm chops...home free, mon!

There are many companies manufacturing phase; it's a common effect. Even MXR tried to outdo themselves with a Super 90 which was a wider orange box, adding some different wave settings. Why doesn't it sound as rich and full as the simple 90? Who knows. There's no overstating the versatility of this pedal, especially when handling any kind of rhythm work on your instrument. Soloing with the pedal makes the notes sound too washy for my taste and I have a tendency to use it primarily in rhythm. And it doesn't mix well with a wah-wah (too much loss of control in cancellation). But for the $100 to $120 you'll pay for this pedal (maybe even cheaper), you'll be adding a very rich tonal variation to break up the thin tone of no effects.

MXR is one of the best of the analog pedal companies, both in their sturdy metal box design and the uniqueness of their sounds. This pedal contains the similar thin sturdy steel design with a simple in out 1/4 on either side. There are two knobs, the left is gain or volume the right is 'distortion.' Please note that there have been many versions of this little box made; I believe there was a corporate shift during the 80s and it is desirable to find the original MXR analog pedals. I found this one in a music shop in '07 for $100.00 and it was a deal. The originals are super rare and are considered the 'godfather' in 80s metal and hard rock. The one I'm reviewing is an original from 1981 and is essentially the same exact pedal Eddie Van Halen would be using during the time. This is a true "Fuzz Box," before the tone was called that. It was just DISTORTION +. Interesting, it's got a '+' on it, it means there's more distortion than one without the '+'? Let's find out...

The only problem with this pedal is that it isn't really powerful, or even very useful, at low settings. Undoubtedly there are resistors that can be added to boost the distorted signal (one shop guy added such a transistor to an old Dist+ and showed me the tonal difference), but you've essentially got to 'put it on 10' on both dials to get the magical effect its renowned for. Well, not ten. There's more headroom and tonal space in the last half-inch of dial than in the rest of it. Reasons for this is that whenever tone (i.e. from your pickups and your pick) the pedal catches it kind of squeezes (compresses) and this sort of compartmentalizes the tone, essentially making it 'sound' quieter. So that's what the volume or boost is for. This pedal is almost exclusive to the hard rock, heavy metal, goth/industrial side of things, though if you get a little washy with other settings, you can hear the more progressive side of rock as well. For example in the old prog rock they would kick out some serious fuzzy sustain, probably in combo with this kind of pedal and a delay. It's absolutely sturdy and mine is held together with rubber bands.

Take a gibson SG and run it right through a dist+ into a marshall amp. Put both knobs at about 4:30 on the dial and turn up. Give it a strum...there it will be. Sense-shattering teeth grinding gothic goodness. To test whether this pedal could turn anything at all into a 'heavy metal machine' I ran a thin strung Telecaster into a Blues Junior Fender amp. Not exactly Merciful Fate setup, if you know what I mean. Since Fenders have less 'mid-rangey' tone, they aren't the best choice for 'heavy metal;' well it still completely crushed. Seriously, one of these old pedals in good working order with the right gear and perhaps a tube driver and you won't NEED a distortion channel. You'll have one in your pedal chain already. I'm still trying to get that "Steve Howe" or "Steve Hackett" out of it and for that kind of music it's a little trickier. But for in your face crunch, this little box is stomp-ready.