M133 Micro Amp review by MXR

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  • Sound: 8
  • Overall Impression: 9
  • Reliability & Durability: 8
  • Ease of Use: 8
  • Reviewer's score: 8.3 Superb
  • Users' score: 9 (4 votes)
MXR: M133 Micro Amp

Price paid: € 74

Purchased from: Guitar Shop, Bucharest, Romania

Sound — 8
Well, I'm using quite a few guitars (see the comprehensive list in my profile): a Tele-shaped one, two Strat-type and an LP-type, all in excellent condition and gig-ready. My amp is a Vox Night Train with cabinet, and the pedals are: Mad Professor Compressor, Seymour Duncan Lava Box, Hard Wire CR-7 Chorus, and, just in case, a Rocktron Hush Pedal. The MXR Micro Amp came in front of this chain, replacing a previous Seymour Duncan Pickup Booster (who only had an input impedance of 500 Kohms and it didn't serve its purpose, although being a good pedal itself). The MXR isn't noisy at all and it does its job, as I said, without altering the guitar's dry signal, unless you crank it up: then it shows some smooth distortion. I didn't buy it for the tone, but for its regulating function when placed in front of a pedals chain. That's a thing I've learned from David Gilmour, who's using a Pete Cornish LD to do that, but I didn't think it worths spending 200 GBP plus delivery, given my limited needs. The unassuming MXR does this regulation function in a most satisfactory way. I'm aware it's not a Pete Cornish: it distorts a little when pushed to high-gain, it doesn't have Pete Cornish's radio filter, and also its electronics are stock stuff. But, since I don't play in venues with persistent radio interferences and I don't need to crank it up, it is effective, thus helping me to preserve an even signal no matter how long my cables are, which guitar I'm using or how many of the effects in my chain are switched off.

Overall Impression — 9
I play Classic Rock, Progressive and Blues. It is vital for me to have a clean dry signal, whether I play clean or I use some pedals. The MXR Micro Amp proved to be a good choice, regardless the fact I'm not quite using it for its main feature (which is boosting the dry signal coming out of your guitar). Being silent and clean, it offers me a clear, neat dry signal that I can blend, subsequently, with my other effects, without altering the tone. It also helps me use different types of guitars (provided with single coils or humbuckers) without re-adjusting the pedalboard's settings. And, finally, it gives me an even signal regardless the number of effects are on and off. If stolen? Oh, Lord! I'm quite poor, so loosing it would be a real misfortune. I'd buy it again, unless meanwhile I get rich and afford a Pete Cornish (which is not likely to happen in my lifetime, maybe after!). I love it's clean and silent all the time. It doesn't ruin your tone, as many other pre-amps (I've also tried, just to make up my mind, a Carl Martin tube-driven pedal: same input impedance, but adding distortion right when you needed it the least). You might get fancy and go for a tube pedal, but, unless it has the same input impedance as the amp - usually 1 Mohm, - it might smooth your tone, but it might also add unwanted dirt to the signal. I wish it had a radio filter too, but, hey, it costs only a fraction of what David Gilmour can afford, and I can only play a little fraction of what Dave plays... Just joking: the MXR Micro Amp is good as it is. It is simple and effective, surprisingly quiet and clean. Good overall impression.

Reliability & Durability — 8
Since I don't want to pay 200 GBP, of course I depend on this little box who does miracles in front of my effects chain (my sound engineer gave me a bottle of Laphroaig, as a gift for helping him keep the signal even, during the gig). You can gig without a backup, given the fact it's an useful tool, but not a compulsory one. So, if it betrays you, you can keep on gigging by switching it off, the bypass being truly effective. It's too early to judge its reliability - I promise to keep you informed if anything bad occurs, - all I can say now is it looks sturdy in its metal case and, given MXR's good reputation, I assume there won't be reliability issues in the foreseeble future. I rated it an 8 for Reliability & Durability because it came without a manual, so I'm in the dark about the way it works, about the problems that might occur, and I hate this.

Ease of Use — 8
It's a very simple pedal and it's also hard to speak about it as an "effects pedal", since it doesn't add any specific effect to your sound. In fact, its main feature is to pre-amp your guitar sound as it is, without modifying it. It has only one knob, dubbed as "Gain": you turn it to the right, the volume of your guitar increases; you turn it leftwards, it decreases. Ideally, it would do all this without adding "dirt" to the dry signal. I bought mine in order to plug it in front of my effects chain, to take advantage of its input impedance (1 Mohm), identical to the input impedance of my amp, which makes all the chain work at an even level, without signal losses. In order to do so, it had to be a very "clean" pedal. And it is indeed. Only at the highest gain it adds a little clipping to the dry signal, but, since I don't need this gain, I only use 10% of the gain, keeping the dry signal as clean as it comes from the guitar. My MXR Micro Amp came with no manual at all. I couldn't find out where was it made or when, but, since the guy at the Guitar Shop told me they sell well (mine had to be brought from the warehouse, the last one in the shop being sold two days before), I assume it's a 2011 product, made somewhere in the Far East. It would be too cheap to be made in the USA, I reckon.

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