Peavey PMA 70+ Studio Monitor Amplifier - Used
Peavey's AMR PMA 70+ uses a unique variation of Class G/H to deliver momentary levels of 100W from a 35W continuous-output amplifier. Unlike the typical Class G/H, the PMA70+ doesn't use multiple fixed-rail voltages. Instead, a specialized voltage doubler circuit generates higher rails on demand. The amount of peak power available is limited by the doubler's storage capacity and how fast you recharge the doubler's capacitors. To better match the power demands of typical musical waveforms, the boost capacitor is only recharged at a rate that supports 60 watts RMS, and this is thermally limited to no more than about 15 seconds of continuous boost. If you've ever looked at music on an oscilloscope or even on a peak-reading meter, you will notice that music only hits its highest peaks for small fractions of a second with average power levels 6-10dB below that. The PMA70+ delivers momentary output equal to a 100W amp but with a size and cost closer to a 35W amp. This amp is popular for driving headphone systems in recording studios and for small near-field monitor speakers.