An alternative to the Tech21 bass flyrig and having owned two of the Tech21 I think this is better IMO.  TUNER: First in line is a big, bright, fast and accurate tuner so you can play confidently in tune. BOOST COMP: BOOST COMP is a booster and compressor combo. Set-to-forget knobs make it simply diabolical. DIRTY Q: The DIRTY Q module is an envelope filter with some interesting tricks. Tweak the knobs onboard until you find the vocal tone t