The best re-amp box. The debate is finally over. United’s Replay Box offers the very best performance and options for re-amplification. Whether you’re producing the most tone-savvy musician or experimenting with sound design, the Replay Box performs on a level all of its own — with an ultra-quiet design and flexible tone voicing. With two different custom transformers for two unique sonic fingerprints and all of the gain you need, the Replay Box raises the bar for all recordists.Replay Box features two independent reamplification circuits: Transparent and Harmonic.The Transparent circuit features our custom-wound, US-made, 5043 step up transformer, which provides extraordinary signal isolation and noise rejection for mastering-grade quality.Harmonic mode engages an alternate transformer specifically designed to add character. This transformer is wound to offer a steeper gain ratio alongside a very gentle rolling-off of the uppermost high frequencies.The Replay Box was designed from the ground up to solve the two most common problems found in re-amping: noise and low gain.