MXR® Bass Compressor

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.

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.

Bass compression is a subtle tool/effect that is easily misunderstood, misused, and underrated. After lots of time debating the hundreds of compressors out there, I decided on this one for 4 things:1) Functionality - the kind of controls that you get here aren't usually found at this price. The LED metering is great and lets you know how much input to dial in, I only know of a couple other that do this, and they go for $250+.2) Ease of use - the manual gets you up and running in minutes, but patience and more use will allow me to fully utilize this effect3) Sound - fattens my tone like a compressor should, but will also work as a limiter when the situation calls for it.4) Reliability in the manufacturer - I've heard about a number of these not turning on, not responding to inputs, hissing, etc. For my money, I wanted peace of mind in a trusted brand like MXR.P.S. While the manual won't tell you, this pedal will also accept higher voltages, and I run mine through my 18V voodoo. I'l put a picture up soon.