Beautiful sounding. Very-very little feedback....none when facing away from speakers. Just one minor issue: Installation, if your guitar has a small hole or close to the measurements of the M80, you will need to take off one, if not both, of the support pads. It took a little doing, but I got it to work and fit in the hole. If you have big-hands/fingers.....forget about it. Drilling the hole for the plug in was a little crazy (I was installing this on my first "good" guitar I purchased in 1980.....was nervous as hell). TAKE YOUR TIME. Start small and work your way up....little by little. No problems. Again, the M80 truly reproduces the sound of your guitar; clear and crisp sound! If you love the sound of your guitar, you'll love the sound of the M80.