150 watts per channel is more than sufficient provided that the amps can safely drive 4 ohm loads. The only reason I mention this is I believe the Transcendents are an OTL design. I can drive Songtowers(1 db more efficient) with one AVA Ultimate 70(35-40 tube wpc) to unreasonable levels. If I bridge my U70s(2 to 3 times the wpc), I can run my HT3s(8 ohm speakers) as loud as I can stand, but still a safe load using the amplifiers' 4 ohm taps. If I use the amplifiers bridged with the 4 ohm Songtowers, I use Speltz Zeroformers to increase the load.