Used but works well - suit installation amplifier

http://www.toacanada.com/assets/files/500-A_Series.pdf

THE TOA 500 SERIES MIXER/POWER AMPLIFIERS are ideal for a wide variety of installed sound applications. Engineered with proven TOA quality and reliability, the 500 Series is simple to install and operate, saving you time and money. The A-503A (30 W), A-506A (60 W), and A-512A (120 W) Mixer/ Amplifiers each have six input channels to accommodate a variety of input sources and a built-in power amplifier with transformerisolated 25 V, 70 V and 4 ohm speaker outputs. Pre-Out/Power-In jacks allow connection of external signal processing between the mixer and amplifier sections. Other features include booster and tape outputs for connecting an external mixer, amplifier or recording device. A convenient +24 VDC input allows operation in remote applications.