Electro Harmonix Nano Bass Big Muff

Pretty much the headline. When I put it in my signal chain (with bass, starting with Polytune's buffer and ending with Pure Tone buffer), I first engaged it, loved it, then disengaged to play something else... And I was stunned. Harmonics disappeared, my over-the top modded Sterling with EMG pickup lost its slight, funky growl... It made my bass dull in BYPASS!

Unusable for me, will return.