MXR M87 Bass Compressor Pedal - Professional Bass Guitar Effects Pedal for Studio & Live Performance | Perfect for Recording, Gigs & Practice Sessions

I bought this at the advising of a bass player friend of mine. It works well, but you have to be prepared for a bit of fettling with it. Getting unity can be challenging because the controls are not that intuitive if you aren't a sound guy. If you combine it with any sort of DI analog amp simulator it can be even more challenging. That being said, be patient with it and it will give you the compression you need and control you desire.I use it as a mild dynamic range compressor, it generally is on for the E string and sometimes the A.The effect is subtle, evens out the note volumes and adds a little to the sustain the way I have it dialed in. You can use a compressor for other things, but that's what I wanted it for. Another reviewer said a compressor on bass is better felt than heard, that's exactly right, it makes you seem like a better player, and makes it easier on the sound guys because your peak volume is more consistent.I had to front-end it with the MXR-M81 preamp since I have a passive bass. This pedal is not intended to be used as a preamp from what I can tell, it adds some hiss and doesn't have enough gain to be effective for that purpose, my bass couldn't even light up the lights on highest gain. But if you hit it with line-level inputs it shines.It appears to draw power from the moment you plug in to the input jack, turning on bypass does not appear to stop current draw like the tuner and preamp pedal do, so keep that in mind when you are figuring battery life. I learned this the hard way. A nice feature is when the battery dies it silently goes into bypass mode. A few of the LED lights stick on for a while as a low battery indicator, but it's already in bypass mode when you see that.My settings are 12:00 for input, output, and attack, 3:00 for release, and 4:1 ratio. My low E string hit hard will almost light up all the LEDS, the A string not so much, and the D and E hardly at all, so mostly it stops the E from overpowering the rest of the strings. When played softly I don't hit the limit so my soft dynamic range is still accessible for expressiveness o soft parts, and cleans me up a bit on the loud ones. I love this pedal and won't play without it now. Wish I had bought it years ago.Great compressor once you know how to dial it in. Originally I was setting it up for tapping and somewhat required a relatively high setting on the Input and lowering of the Output. This resulted in a loss of the low end.At first I thought it was the pedal and was annoyed/irritated that even an expensive pedal such as this still had tone loss. Once I started to dial everything back for slap all my lows reappeared and was even able to find a setting the suited both.The easiest way to kill this pedal is by having your bass lows too high. It's better to have just enough and boost it after this pedal. Currently this is first in my signal chain followed by the B7K Ultra where I add just a touch of more bass.You'll know right away if you have too much low end or if the settings are too restrictive by looking at the Gain Reduction meter on the pedal. Depending on what you want, if you hit an open E and the meter shoots 25% that may work for you, but 50+% is probably worth evaluating what you have set up. Right now I have it to where slap will trigger it and an open E barely triggers, if at all.The M87 has a quite a few features that the others do not have. The first noticeable difference is the LED meter. While this is almost common nowadays on rack mounted compressors, it is not on pedals. I found the meter to be quite helpful in adjusting the input and output controls, along with the release, attack, and ratio adjustments needed to get the performance out of the pedal that I wanted.Another great feature of the M87 is the input and output ratio. I was able to adjust my input at a higher level, and keep the output at a lower level to give a more balanced and level sound for the different styles and techniques used. The M87 also has a foot switch that allows you to have the pedal on, or in true bypass mode with a blue light as an indicator to let you know which mode is currently functioning. The M87 can be powered with one 9 volt battery or with an adapter/power supply. The housing is small and durable. Everything is detailed to read in an easy way and this device is a powerhouse that everyone should have in their lineup. The instructions that came with the M87 are very thorough, which makes it easier for those that may not yet fully understand the aspects and effect that a compressor can have on your sound.3/5, great tone and adjust-ability but issues with degrading performance over time.I've owned this pedal for about 3 years and it still does a pretty good job however its performance has degraded over time. Initially, and for the first two years or so the pedal worked well. I love the tone and was able to get a good punchy sound and maintain attack. I like the many knobs that allow you to dial in precisely the amount and shape of compression that you want. After two years or so I noticed that when I plugged the pedal in, all the LEDs would light up, as if it was seeing a very hot signal at the input. This was strange but went away after about a minute and would go away more quickly if the release knob was turned all the way up. Additionally, I'm hearing more and more distortion as time goes on, especially if the input level is turned up. This prevents me from getting more compression and I'm forced to settle with medium/mild compression without significant distortion. I contacted support and they charge a flat $75 for out-of-warranty pedals which seems steep at 40% of the original price.This works well at making volume more consistent, or can be turned right up to add distortion. I used it at the end of the signal chain mostly to level out occasionally excessive volume from the envelope filter or from slap/pop and to make volumes of normal playing more consistent.However, I mostly just used it at home for practice and didn't particularly like not hearing where I had played something too softly/hard - not ideal for practicing and building a good technique. And I found that it took the life out of slap/pop, and killed the sub bass when I EQ ahead of it for a dubby tone, and it raised unwanted fret noise, and worst of all for practicing - it made me feel a bit disconnected from the sound.....all things that I'm sure many other players could deal with, or of course the compressor settings can be dialed down but by doing that I found it probably wasn't the best way to spend £171 and take up pedal board space.I returned it as it's not needed for the majority of what I do - practicing at home and recording to Laptop (via Logic that has a compressor), but it is well built and does what it is supposed to do well. I can see that it would be especially useful for playing live so I might well end up buying this again in a couple of years if I start doing that.I saved about £70 by replacing this with a Boss RC3 looper. Not something most 'must have' bass pedal lists include (whereas most would include a compressor) but I would recommend this more for someone more focused on practice rather than playing live.I upgraded from a cheaper compressor to this..the tonal control is a chalk and cheese difference. The adjustability offered may be too complex for entry level use but is worth taking the time to explore it's potential.Does a really good compression job but the input needs to be turned up quite high for even an active bass and on some of my piezo instruments I can't get the level high enough for any compression to take place at all. At these high input settings there's a noticeable clunk when I turn it on and off so I'm going to have to find some sort of preamp. pedal too.Great Bass Compressor. One of the best pedal ever.Doesn't change my bass tone at all. Just the dynamic of it.It is the only effect on my pedal-board ever on.The compression dynamic display is great too.Only issue: the "on" led is too bright, but this can be easily managed :-)Barely noticeable until you turn it off, at least thats the setting I like but it can also heavily compress. Handy for tone sculpting without sacrificing low end clarity. Good value