Zoom A1 Four Multi-Effects Processor WAV Upright Basses An external audio source can

An external audio source can be connected to the control box for play-along practice

TAP Footswitch and LED

but only slightly and if left on for unamplified playing

And with the expressive Freeze function

so the WAV viola works best when plugged into an amp with a Hi-Z input

Zoom A1 Four Multi-Effects Processor WAV Upright Basses An external audio source canWith specially engineered effects, built in looper and drum machine, the Zoom A1 FOUR is the first Multi Effects Processor designed for a variety of acoustic string and wind instruments, including bowed strings! The A1FOUR is preloaded with over 80 effects, including more than 35 new groundbreaking effects designed and engineered for acoustic instruments. The A1 FOUR comes with 8 additional pedal controlled effects to adjust volume, pitch, reverb,