Since the arrival of my Insight 240 amplifier (built in a compact chassis, very nice!), I've been able to use the headphone feature of my OmegaStar PAT-5 preamp. My previous amplifier, a Linn LK2, was not a common ground device, so I used the EPL button to send the signal to a Grado RA-1 headphone amplifier. Despite the easy-to-drive character of my SR 125 headphones, the Grado RA-1 took the listening experience to a level well beyond any headphone jack I'd used. Amazingly, listening through the PAT-5, which simply drives the headphones from the power amp, is even better! Records I had previously excused as simply not of the best recording quality have taken on added richness, spatial quality, and dynamics. Especially enjoyable have been the previously-ignored choral works in my collection. The increased spatial and tonal separation of a choir's different sections, and even individual voices, make their interplay easier to follow, musically comprehensible, and, for the first time, actually enjoyable!!