As our own Alvin Gold reported in HFC 327 in his review of Denon's new DCD-2010AE CD/SACD player and PMA-2010AE integrated, Denon have replaced their DCD-SA1 and PMA-SA1 predecessors in Japan with special domestic market models.

The PMA-SX is based on the same concept of simplicity of circuit construction as Denon's original Ultra-High Current MOS-FET amplifier, the POA-S1 of 1993, and the new PMA-2010AE. The push-pull output stage consists of a single pair of UHC-MOS devices in a cascode bootstrap arrangement, which Denon chose in order to minimise the impact of device junction capacitance and improve temperature stability. Like other manufacturers who adopt this single device pair approach, Denon claim the benefits are greater transparency and improved levels of detail.

Like the PMA-2010AE, the SX amp uses a large volume potentiometer claimed to offer better attentuation resolution. Vibration resistance is apparently improved by the fact that the control is housed inside a brass case.

The amplifier itself is split into six sub-sections - MM phono/line input stage, volume control, voltage amplification, power amplification, power supply, and control. The latter has its own winding on the mains tranformer, which is located on a sand-cast isolation block, along with the main reservoir capacitors, above one of the amp's feet to help 'drain' vibration out of the chassis. The capacitors used throughout the amp are audio-grade types, and the rectifiers Schottkies. All this adds up to a mass of 30kgs, 50 watts into an eight-ohm load, and 100 watts into a four-ohm load.