Mesa/Boogie Triple Rectifier 3-channel, 150-watt Tube Amplifier Head Features at a Glance:MULTI-WATT 50-watt/150-watt, Class A/B powerTube complement: 6 x 6L6, 5 x 12AX7, 3 x 5U4Bias Select switch (6L6/EL34)Fixed bias for consistent, maintenance free performance3 fully independent channels with 8 m..