To create its output, the PA-10 uses a combination of tube pre-amplification and solid-state, MOSFET power amplification. The idea is, as always with hybrid amplification, for the tubes to provide rich, warm tone while the MOSFETs concentrate on turning that into a strong, clean signal. The approach doesn’t work every single time, but when it does you usually get a great result.
And so is the case here. The sound the PA-10 puts out is perfectly lovable, with a warm, creamy tone, a strong bass response and a clear top-end. At first it’s actually a bit brash when it comes to treble; not enough to create a wearying noise, but enough to make the sound a little too bright for some tastes.
However, after a few hours that treble starts to round off nicely, and the PA-10 is just pure pleasure to listen to, putting in a strong performance with dance, electronica, classical , indie, folk and even country but especially – and maybe this is the tubes – old-school, classic rock.
I tried it out with four sets of headphones: the Grado SR125is, Sennheiser’s HD595s, a pair of BeyerDynamic DT770 Pros and my cheap and cheerful AKG K141 Mark IIs. The results with all sets was fantastic, but especially so with the HD595s, where the added warmth and low-end richness compensated for what few weaknesses there are in the Sennheiser’s controlled, well-balanced sound.
The PA-10 gets scarily loud before you even hit half volume, so there’s no problem driving the high impedance DT770 Pros, and my only worry was that, with bass-heavy tracks like Ladyhawke’s From Dusk ‘til Dawn, the bass was actually a bit too pronounced and boomy, to the detriment of the rest of the mix.
With the Sennheisers or the Grados hooked up, however, and some tasty tracks emanating from my iPod using a line-out dock, there were plenty of treats to be had. The PA-10 does great things with intimate, acoustic music, and tracks from k.d. Lang and Alison Krauss revealed gorgeous, rich vocals and a mass of instrumental detail.