MXR Blue Box

MXR Blue Box

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It takes your signal, fuzzes it up, then duplicates it two octaves down. You can control the output and also the mix between the dry signal and the effect. Using the 100% wet is quite an experience, but more recognizable sound will appear as the dry signal increases. The Blue Box is known for having a somewhat chaotic persona that can make each session of use a totally unique experience.


Manufacturer’s Suggested Retail Price: $115.50

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User Reviews of the MXR Blue Box

  • Submitted by el_hombre from Auckland (26 points) on Nov 5, 2009
  • I bought this after reading the reviews and watching the demos. Looking for some rumbling drones to add to my chain. So I bought the blue Box. I've had it for a couple for months now, so far I love it. I really like the fuzz you get from this thing. and the noises, well those have been covered nicely already. Currently I use it with the output on full due to the volume drop. I have the blend at about 3 0clock to get some of the octave drop in there as well, knowing that total chaos is only a twist away. I'm looking at doing the C11 mod to get rid of the volume issue so I can look at moving it around the chain a bit. I play heavy drone stuff so this is a good lil addition to that. One thing I'd like to look at is this pedal vs the DOD Buzz Box. I have a buzz box and hate it. Can't stand it at all and I still shudder when I think of it. The Blue Box for me is a warmer pedal than the buzz which I find to have anasty, harsh digital sound. I'd recomment the blue box over the buzz any day without hesitation.
  • Good Points: Warm sounding fuzz, insane chaotic octave drop. Solid build.
  • Bad Points: The volume drop, the awkward battery access.
  • Price Paid: US$60.00
  • Purchased At: ebay
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  • Submitted by Most from Erie, PA (18 points) on Nov 27, 2008
  • I did the C11 mod, first clipping one prong of the capacitor and listening and then clipping both - removing the thing completely. What I want to know is, WHAT THE HELL are people talking about? Maybe MXR is doing something new (bought this in mid 2008,) but clipping that C11 off was a DISASTER: the box barely makes noise now AT ALL... OUTPUT must be all the way up or pretty close to that, and the BLEND knob now has no noticeable effect whatsoever. So: what the hell is everyone talking about?, what went wrong?, and does anyone know anyone who does a professional modification of this pedal? Something must've gone wrong???
  • Good Points: unpredictability is interesting and engaging for the player
  • Bad Points: Easy to overdo things with all the noise involved.
  • Price Paid: US$85.00
  • Purchased At: Ebay
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  • Submitted by chadwick from Cathedral City, CA (14 points) on Aug 20, 2008
  • well i use this as my one and only "gigging" dirt box with the bass; a/b'ed coming out of a boss pn-2 into two amps...i can create a wall of sound for 80's japanese noisecore that i just could not get with a proco rat or a big muff...maybe because this is a fuzz and not a distortion box...the gating on this eliminates the tick-tock of the pn-2 when the pn-2 is off...the c11 mod is essential with this pedal in my opinion...when i plug this into my copilot antenna2 (lo-fi ring mod/bit crusher) it goes nuts whether before or after...also likes reverse delay too for some reason
  • Good Points: has no eq nor gain knob to fool with which keeps things simple...when i want to twiddle knobs i break out my king capitol punishment glamour box...this is nice and simple and tiny!
  • Bad Points: the stomp switch on these reissues is sub par/flimsy in my opinion just imploring to break
  • Price Paid: US$60.00
  • Purchased At: second hand/classifieds
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  • Submitted by provera from Waterloo, IA (156 points) on Feb 22, 2007
  • Not a lot to add here except Shawn has a handy ultrasimple guide to removing the c11 capacitor which will solve all your volume problems: http://www.noisefx.com/article/mxr_blue_box_mod Keeping it on a switch might seem like a pointless idea, but it's actually good to have the potential to use the blue box as a limiter now and again.
  • Good Points: Definitely unique Can be good for traditional uses Great for weird lofi/8bit/555 freakouts
  • Bad Points: Was kinda pricy but getting better thanks to reissue
  • Price Paid: US$40.00
  • Purchased At: ebay
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  • Submitted by Iain David from United Kingdom (140 points) on Sep 21, 2006
  • As stated already this is basically a synthy square-wave fuzz that blends yr signal with a duplicate two octaves lower. Apart from the obvious tracking issues which make it ideal for noise music it's other intriguing characteristic is the way it gates the signal. You can get some really wierd whoosing sounds by using this with a guitar and just rubbing yr fingers quicky up and down the fretboard without depressing the strings. Alternatively, when used with certain modulation devices this starts to sound really synthy and pixellated. These effects are incresed when the blend knob is turned further anti-clockwise. With the blend turned clockwise past around 12 o'clock the signal starts to even out and the random octave jumps become far less frequennt to the point where you eventually just have a wierd gated fuzz sound. One major drawback with this pedal is the chronic loss of volume. This really needs tro be used in conjunction with a distortion pedal if yr looking for a strong output signal (although it can just be useful on it's own if you want the sound to be a little more "blurred"). Personally I never encountered any of the battery life problems mentioned below. Not really a concern now i'm running it from an adapter. I consider myself lucky because the battery placement couldn't really be more inconvenient!
  • Good Points: - Nasty synthy fuzz sound. - Wierd gating. - Octave jumps my make it sounds like an audio halucination featuring an army of 8-bit Nintendo consoles marching through a thunderstorm.
  • Bad Points: - Volume drop. - Terribly battery placement.
  • Price Paid: US$0.00
  • Purchased At: ebay
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  • Submitted by Frank from Chicago, IL (52 points) on May 8, 2006
  • First of all, contrary to popular belief this thing is completely controllable. Feed it a signal w/ strong sharp volume peaks, especially one w/ lots of treble and it goes buck nuts and glitches, tracks poorly and generally has noisy good time. Give a mellower signal at a constant volume and you can get it to track perfectly. Admittedly, it takes practice but it will if you get it right. You want higher register pitches but w/ the treble cut if you want it to track right. When you feed low pitches into it, it tends to just rumble--which is cool in it's own right. It doesn't generate a two ocatave lower-tone strictly. The circuit is based on a really simple ring mod and that's why it will behave unpredictably. It makes it do some fun things beyond a straight octave down. If you feed it a sliding pitch going upwards, at some point, it will actually jump down an octave. Fun stuff. Experiment w/ it and you'll get a lot more uses out of it than putting it in a feedback loop and letting it take over. You'll probably want two things to use w/ this at leas. One is either mod it to be true bypass or buy a seperate pedal that can take it out of your signal chain when it's off. The other is something to boost the signal when it's on. The advantage of getting a pedal that can take it out of you chain is you can put a distortion pedal (or whatever to boost the signal) right in line w/ it and turn them both on and off w/ the press of a button.
  • Good Points: Sturdy, sleek, simple and crazy.
  • Bad Points: Noisy and sucks tone when off, loses volume when on.
  • Price Paid: US$50.00
  • Purchased At: Some pawn shop
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  • Submitted by kinetic turtle from Oakland, CA (162 points) on Mar 9, 2006
  • Not a lot to add to the existing reviews. Unpredictable in a good way, especially in a feedback loop. Very enjoyable. Reacts great to sound sources that are already moving all over the place.
  • Good Points: Tough construction. Unpredictability.
  • Bad Points: Useless in many settings; this pedal frequently has to be cranked all the way to get anything meaningful out of it.
  • Price Paid: US$0.00
  • Purchased At:
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  • Submitted by tapesss from Brooksville, FL (336 points) on Jul 17, 2005
  • i finally shelled out for one of these, and i must say it was a good investment. this pedal is awesome. all kinds of clicks, sputtering, poorly tracking octave effects, and a really strange gated squarewave fuzz. the volume drop is kind of irritating, but throw a DOD death metal after it and there you go, problem solved. in a feedback loop, it makes some pretty unique rumbling sounds. the blend control was kind of odd to me at first; turning the blend knob all the way counter-clockwise is the full on, no-original-signal octave effect, turning it clockwise adds more of the signal, and all the way clockwise is just an odd fuzztone. combine this with grunge pedal and you have a buzz box(basically).
  • Good Points: great sounds, the gating gives your sound an interesting texture, poor tracking on the octave is a lot of fun to mess around with. it's enexpensive, and coupled with a grunge pedal, it's a really cheap alternative to a buzz box. the case is super heavy duty, built like a tank.
  • Bad Points: the pop that the footswitch makes, volume drop can be irritating.
  • Price Paid: US$75.00
  • Purchased At: eBay (tunnelvisionmusic)
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  • Submitted by fran from Nottingham (64 points) on Mar 17, 2005
  • I was looking for an evil fuzz type pedal and the MXR Blue Box delivered! This is a fuzz box with a built in noise gate and a two octaves down added effect depending on how much you dial in on the blend knob. this pedal oscillates and goes mad if the blend is over halfway, i asked an old MXR rep. why this is & he said it was a design flaw...but because of this the pedal had gained "cult status". If you dial in blend on full it resenbles the end of the world, the fuzz is nasty too, instead of sustaining out gracefully it splutters because of the noise gate. This is a great pedal. The only complaint is the volume drops when in use, there is a simple mod. for this (cutting one leg off the C11 capacitor above the level/volume pot) this increases volume and treble.If your sick of sweet valve sounds or crystalline digital purity get a blue box!
  • Good Points: Evil fucker, unpredictable, vicious fuzz to nintendo-playing through a distorted knackered amp, nuclear-proof case, looks cool and a definite head-turner...this pedal will get you noticed and frighten sound engineers!
  • Bad Points: The usual bad battery access, drop in volume.
  • Price Paid: US$0.00
  • Purchased At: ebay/music store
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  • Submitted by Marco from Brescia (134 points) on Oct 25, 2004
  • Sick and nasty sound. The blend knob is like a road to hell: turn it and go from a huge low fuzz to a total madness. One thing: the volume knob is USELESS. There is an horrible volume drop. Must be used with a boost (I use an FZ-2 or the controls of my line selector)
  • Good Points: -great crazy noisy sounds -awesome octave tracking -good fuzz distortion with blend at max
  • Bad Points: I hate the volume drop!!!
  • Price Paid: US$60.00
  • Purchased At: E-Bay
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  • Submitted by Brandon from Collinsville, IL (100 points) on Oct 10, 2004
  • To be quite honest, I wasn't exactly thrilled with this unit when I first got it. Sucks the hell out of the volume in your chain, and more often than not with the effect on full blast pretty much everything you feed into it sounds the same. What made me decide to keep it was the way this fucker behaves in a feedback loop. My god! This thing goes absolutely apeshit in a loop. Totally unstable and mutilates like all hell.
  • Good Points: Unstable and oftentimes random. Good for keeping you on your toes. Built to take abuse. Chanked out distortion
  • Bad Points: Sucks volume like a cheap whore. Needs a different style of knob to be used for hi speed twiddling. Generally only fun when used in a feedback loop
  • Price Paid: US$0.00
  • Purchased At: Swing City Music
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  • Submitted by gr-eh? from Detroit, MI (374 points) on Sep 27, 2004
  • dunno what that d&d dude is going on about, but he's right. totally unpredictable octave distortion grossness. bass/synth/vomit sounds erupt from this thing at the mere though of sending some signal through it. really do prefer it with an extra distortion after it to give it that boost.
  • Good Points: sounds totally sick, perfect for that bass gnarl. oh yeah, and king buzzo uses it..
  • Bad Points: unpredictable?! might be a bad thing to some..
  • Price Paid: US$0.00
  • Purchased At: chuck d owns it
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  • Submitted by fat cobra from Seattle, WA (6 points) on Sep 22, 2004
  • Most effect pedals only do what you tell them. Turn knob A and get this sound, turn knob B to alter sound blah blah blah. But this pedal stages its own revolt/temper tantrum within its ablities. Some times it will randomly throw in octave effects. Tuning the blend knob can only control it so much. Its a wild stallion that cannot be bridled. Its a d+d random encounter table, it might be orcs or a pile of +3 swords.
  • Good Points: its crazy, makes most everything sound like 1970s arcade games or 2-bit earthquakes
  • Bad Points: eats batteries in about 2 hours
  • Price Paid: US$89.00
  • Purchased At: local guitar store
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  • Submitted by ck3 from Portland, ME (390 points) on Sep 21, 2004
  • This little blue tank of a pedal is capable of producing anything from glitchy 8-bit Nintendo sound fx to throbbing industrial rumbles. If you don't want to lose volume, it can help to place another fuzz, an eq, or a preamp after it in a feedback loop ... and it sounds awesome placed in a chain after an Oscillating Fuzz.
  • Good Points: The octave tracking becomes more gloriously abominable as you lower the "blend" setting ... perfect for keeping you on your toes when soloing or making your guitar or keyboard sound utterly septic.
  • Bad Points: For those who prefer a screeching feedback loop or blasting high gain sound, this pedal can be a bit of a buzzkill. The onboard gating prevents it from oscillating on its own in a feedback loop with lower blend settings ... and it can severly hinder output volume when engaged wthout a post boost of some kind.
  • Price Paid: US$80.00
  • Purchased At: American Musical Supply
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  • Submitted by D/A A/D from Halifax (398 points) on Jun 22, 2004
  • I can't say much that hasn't been said, so I will only saw what hasn't... FEEDBACK LOOP!.. This thing not only brings out some lovley character in a feedback loop - it acts as a limiter!.. Really well I may add... Tames my wild and crazy R-Mod...
  • Good Points: Everything... ITS HAS A LIMITER BUILT IN!..
  • Bad Points: Its quite... On its own...
  • Price Paid: US$60.00
  • Purchased At: e-bay
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  • Submitted by nkondi from Portland, OR (570 points) on Apr 25, 2004
  • described as a poor mans buzz box, and since im not the richest kid on the block, i cant compare it to a buzz box. but also said it would make atari noises, and this i can confirm. this thing is wonderfully loud. coupled with a super american metal (i swear that pedal is the love of my life) it sings sweet punctuated highs, and deep fucking balls out distorted lows. do yourselves a favor, dont sit around for that once in a lifetime deal-of-a-buzz-box to come along, go out and get one of these.
  • Good Points: easily adictive compact size great sounds ala loud solid construction
  • Bad Points: battery is a bitch to get at...
  • Price Paid: US$0.00
  • Purchased At: trade at old town music
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  • Submitted by m00k13 from Grand Blanc, MI (40 points) on Mar 16, 2004
  • I've been drooling over the Blue Box for a while and finally picked one up. I run everything from contact mics to vocals through this and the result is very unpredictable. Has a very harsh edge to it. I tend to go through the Blue Box before my delays and can come up with some great sounds.
  • Good Points: Makes just about anything sound like an Atari 2600.
  • Bad Points: none I have found so far
  • Price Paid: US$70.00
  • Purchased At: eBay
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  • Submitted by Kalaab from Chillicothe, IL (24 points) on Feb 9, 2004
  • The MXR Blue Box is a top-notch noisemaker. It's an unruly, uncontrollable fuzz box that does an octive and two octaves below your original and switches between with erratic tracking. Apparently, there's a built-in compressor of some kind to somewhat cage the mayhem this pedal unleashes. An excellent 'secret-weapon' pedal for neat Atari-esque noises.
  • Good Points: Completely unique tones and impossible-to-replicate performances. A one-way ticket to the land of uniqueness. Neat monophonic synth quality.
  • Bad Points:
  • Price Paid: US$70.00
  • Purchased At: eBay
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  • Submitted by d. l. from Wakefield, MA (200 points) on Jul 26, 2003
  • This beauty already has plenty of reviews here but I'd be committing a crime if I didn't submit mine for one of my favorite boxes. It has just two knobs, but you can use the Blue Box as a straight fuzz (sounds more modern and mechanical than typical fuzzes)with the "Blend" fully clockwise, and introduce the very fat sounding bass double octave when turned counter-clockwise. The octave is sometimes stable, but mostly just jumbled chaos =) It's great for wonderfully shit-ifying any sound and turning any instrument into a bass synth. Maybe another knob like "color" or something would've been cool??? I'm being greedy. The Blue Box is the only pedal of which I'd like to get another just because it's so fucking awesome and industrial.
  • Good Points: the size, the solid construction, the look, doesn't eat batteries, inexpensive
  • Bad Points: the typical (but satisfying) on/off footswitch
  • Price Paid: US$50.00
  • Purchased At: ebay
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  • Submitted by Beavis from Afghanistan (254 points) on Feb 15, 2003
  • Very cool pedal. makes things murky and dark fat sounding, though has some volume issues. I don't think you can compare this with the Buzz Box. This is much more useable and signal friendly. Buzz Box just destroys all. None shall pass
  • Good Points: Reliable. Battery friendly. Available. only one bad sound available (blend knob maxed)
  • Bad Points: Can seem a little quiet. Missions to change battery
  • Price Paid: US$69.00
  • Purchased At: Denmark St. London
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  • Submitted by J. from Atlanta, GA (44 points) on Sep 3, 2002
  • This is a great fuzz/octave pedal for darkening and muddying your sound. The sound is warmer and less crisp than the Buzz Box. This pedal frustrates me sometimes because it needs a lot of volume to reach its full effect. Low-volume practice sessions can be unfulfilling. Other than that it sounds great and adds some raunchy sustain and chaos. I have run all sorts of instruments through it to good effect. It's a good noise pedal, and easier to find than the (in my opinion) out of production and inferior DOD Buzz Box.
  • Good Points: Sturdy, easy to use, good chaos generator, reliable, doesn't eat batteries.
  • Bad Points: must remove the bottom of the whole unit to change the battery, needs a lot of volume to drive it properly, can muddify things.
  • Price Paid: US$70.00
  • Purchased At: guitar center
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  • Submitted by K. from Sealy, TX (508 points) on May 23, 2002
  • I tested one out at a local music store w/ a grunge pedal and a minidisc w/ a wide variety of sound sources. If I didn't already have a couple of DOD Buzz Boxes this would make a suitable replacement, just remember it has to be used in conjunction w/ another distortion to get that Buzz Box sound. As stated by many before, the output level on this thing when used alone is pretty weak, and one thing I did notice w/ the unit I tested was that adjusting the blend control didn't change the output sound much, regardless of the type of sound fed through it or whether the Grunge pedal was placed before or after the Blue Box. Not that it's a bad thing, the result was everything was turned into harsh, rumbling noise, w/ little relation to the original sound source. As I said before, if I didn't already have a couple of the DOD boxes I'd buy one of these in a heartbeat, and considering the scarcity and expense of the DOD units, the MXR Blue Box (reissue) is quite a bargain.
  • Good Points: Used w/ another distortion can approximate the sound of the much sought after DOD Buzz Box, more readily available and reasonably priced than the DOD units.
  • Bad Points: Output is rather weak if used by itself, can yield a similar sound regardless of the input signal.
  • Price Paid: US$0.00
  • Purchased At: test driven @ Fuller's Music
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  • Submitted by Gus from San Francisco, CA (266 points) on Apr 6, 2002
  • The fuzz on this is the raspy, square wave type. Very artificial, and somewhat synthesizer like in quality. As a previous reviewer stated, you've got to keep the level knob maxed or you'll get a volume drop. This is also the type of fuzz that kills sustain. This can be kind of neat to create semi random chirps and farts, but it's not too good in a feedback loop. Use with other high gain devices if you want to use it in a loop. The low octave is very synthy, and it tracks when it feels like it (which is almost never). The randomness of the tracking is tailor made for noise (how exactly did they market this to guitar players again?). The octave can generate some real Richter scale lows when the proper kind of signal is fed into it. Unfortunately, even if you keep the controls set on one setting the results you'll get will vary with the mood of the box that day. It'll do something amazing while you're at home, and sound like shit when you're using it in a live situation. It's best to have the sampler handy so you can capture anything good that the box does.
  • Good Points: Buzzing, square wave fuzz combined with a low octave that tracks semi randomly. Atari explosions on tap. A real noise bomb...
  • Bad Points: Not nearly loud enough. Fuzz can kill sustain. Tempermental, so recreating a good sound with it can be difficult.
  • Price Paid: US$0.00
  • Purchased At: Birthday Present (Thanks Mom!)
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  • Submitted by Rob from London (354 points) on Mar 22, 2002
  • Two knobs, one of whcih you have to keep maxed or else you get a volume drop. With the blend knob all the way right you get a sick noisy fuzz, about 1 oclock you get a octave fuzz, 10 oclock it starts jumping randomly from octave to octave and all the way left you get a burbling sound with doesn't let any original signal through. Great for noise, you can get all kinds of jumping about noises and REALLY heavy sounds with another fuzzbox. Replicate a DOD buzz box with this and a DOD grunge pedal! Great little pedal, very reliable too.
  • Good Points: Great for noise, can get really heavy sounds with other pedals. Bizzare jumping sounds and nintendo music.
  • Bad Points: Can't reduce the fuzz. Very little gain - not a main distortion, more of an effect. Bizzare AC socket and you have to open it up with a screwdriver to change the batteries.
  • Price Paid: US$85.00
  • Purchased At: Shop
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  • Submitted by stk from melbourne (8 points) on Nov 4, 2001
  • Very idiosyncratic fuzz box / octave shifter. Seems to pitchshift yr signal down then distort the hell out of it. The actual pitch tracking is, shall i say, 'selective', which of course is great for noise. Creates great waves of sickly bottom end crunch, evil static, and incorporates some kind of noise gate which rudely cuts ot the signal when it gets too low. (That annoys me as I like the hum and hiss that pedals make). I use it thru a bass amp, but there's a lot more (heaving, fuzzy and generally sick) bottom end to be had when DI-ing. The output is pretty low, so best used with some kind of level-boosting device after it.
  • Good Points: noise, noise and noise. Who the hell thought up this thing? Whoever, bless their wicked soul.
  • Bad Points: low output, don't like the gating effect.
  • Price Paid: US$50.00
  • Purchased At: ebay
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  • Submitted by Nick from United Kingdom (14 points) on Sep 19, 2001
  • think 80's computer games. think great big fat deep growl. Think violently unstable octave effect. This pedal is a one-off. It;s not foe everyone - it's probably not for most, but the effect is so unique you have to admire it. It ranges from relatively clean distortion to spidery epyleptic fits. I use it with the sustain from a Big Muff to make it sound a little more human, or without if I'm feeling robotic.
  • Good Points: it's blue, it's a box. it's the angriest sounding pedal ever.
  • Bad Points: your neighbours will hate you forever
  • Price Paid: US$80.00
  • Purchased At: Regent Guitars - UK
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  • Submitted by john from Shelton, CT (12 points) on Aug 12, 2001
  • Cute little pedal. It works much better if you use it in conjunction with another gain boost or distortion. I use mine as the first fx in my line right before a Jekyl and Hyde and a bunch of phasing/shifting fx.
  • Good Points: Its a unique two octave fuzz. The blend knob allows for a subtle octave fuzz, an off the wall mutated, almost random pitch-shifting fuzz, or something inbetween.
  • Bad Points: Kind of a one trick pony. You have to have the output knob cranked all the way in order to maintain amp output. Your amp should be turned up as well.
  • Price Paid: US$80.00
  • Purchased At: musictoyz
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  • Submitted by Johnny from Waterloo, IA (14 points) on Aug 4, 2001
  • It drops what you play by a few octaves. Depending how you set it you will get a really cool tone. The knob on the left is best when you have either all the way up or all the way down. if it's all the way down it an awesome mush of noise and all the way up it sounds like an old Atari or something.
  • Good Points: Sweet noises.
  • Bad Points: You have to play kind of rough with your guitar to get the really cool noise out of it.
  • Price Paid: US$79.00
  • Purchased At: musicicians friend
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