The Reverb pedal works and sound fine with my Ultrasound Acoustic amp. The reverb adds depth to the sound of the guitar. The reverb effect has a clearer tone compare to another reverb pedal I use to own. So a plus for this Align Reverb Pedal. I would suggest a potential buyer consider purchasing the LR Baggs Align Sessions Pedal. I ordered the Session Pedal after John's suggestion. I am glad I followed John's suggestion. Both pedals function well together.