Audio Design Associates MPA-501

The MPA-501 is an incredible five-channel power amplifier with an impressive heritage. Introduced as the MPA-500 in 1992, it became the power amplifier that was utilized to assist in writing THX's original amplifier specification. Based on an audiophile configuration, where a mammoth power supply resides in its own chassis (MPS-500) independent of the chassis housing the five amplifier modules, the MPA-501 is one of the the most powerful multi-channel power amplifiers made. In fact, when operating on a standard 115V AC outlet, you cannot even force the amplifier into clipping because to do so requires 28 amperes of wall current. The MPA-501 incorporates a 2500 Watt custom torroidal power supply in combination with 500,000µF of capacitance. This huge power reservoir ensures that the MPA-501 has plenty of punch for even the most dramatic scenes. Suffice it to say, that the MPA-501 is as good as it gets.

* 5 Channel Power Amplifier
* 400 Watts Per Channel @ 4 Ohms
* 2 Ohm Minimum Safe Impedance
* 0.01% Total Harmonic Distortion @ 8 Ohms
* 3U Fan Cooled Chassis x 2
* IC Controlled Slow Turn-On Circuit
* Separate Power Supply With Military Grade Interconnect
* Torroidal Power Transformer
* Circuit Breaker Protected
* MPA-501 46 lbs. 5.25"H x 19"W x 19"D
* MPS-501 52 lbs. 5.25"H x 19"W x 16.5"D

The MPA-501 and the MPS-500 were sent to the ADA factory in White Plains NY to be refurbished and inputs and outputs  upgraded similar to the MPA-502. The cost with shipping was $1580. There is a depression on the rear of the MPS-500 were the ADA lettering is located. There are also several scratches on the top. Finally, aftermarket sorbothane pads were added for non rack mount applications.