The Plus Audio AC1P is the plug-in amplifier module used in the Easytour (ET) series: Plus Audio describes it as the inbuilt amplifier module of the powered ET118BA subwoofer, and lists it as one of the ways to power the ET110L mid-high cabinet. The supplier lists this part 'for ET118B sub', i.e. as the amplifier unit that makes the subwoofer the amplification and processing hub of a small ET system. On the ET118BA, this Class-D module is built on a Powersoft amplifier platform and delivers 4 x 1600 W at 4 ohms, enough to drive four ET110L mid-highs plus an additional passive ET118B. It uses a universal regulated switch-mode power supply with power factor correction (100 - 240 V, 50 - 60 Hz) and has an integrated 64-bit DSP running at 96 kHz with 2 inputs and 4 outputs, input and output delay, six factory presets (100 total) and optional Dante. Connections are 2 x XLR inputs, 2 x XLR link outputs, 2 x Neutrik NL4MP speaker outputs and PowerCON in/out. THD+N is under 0.05% and SNR 115 dB(A). Intended for users building or upgrading a Plus Audio ET system.