This headphone amplifier receives a favorable review from TechRadar, it offers good detail and extremely revealing sound.

"Firestone specialises in miniature hi-fi, so the diminutive Cute is very much part of the overall range. Its features are very simple, though it does include a gain switch mounted at the rear, which gives 15dB extra boost – this could be of use when driving high-impedance headphones. Inside the unit is a further feature and a most unusual one at that: a pair of switches which allow one to configure the volume control for series or shunt operation, thus giving a slightly different slope to its attenuation. Interesting to try, though it doesn't seem to have any effect on sound quality as such."



Link: TechRadar