this amp that much warmer, true guarantee of pure class A is tightened price (it is minimalist: 1 single RCA input LED + a + 1 + knob headphone jack 6.3 female) and still book with two cables sector which an EU (France). It is preset to 220 US sector. WARNING! Among 3 "Seinnhesser" reference, only the HD 700 headphone (150 ohms / 105 dBSPL) will marries well (very very good even) with the HA 200 NuForce. The latter did not drive out the HD 600 that I own (300 ohms / 97 dBSPL) and probably not much better HD 650 (300 ohms / 102 dBSPL) that I did not ...