Have a classe CA-100 and have owned CA-150. 150 smoked the 100 in the bass. Classe has now gone back to the older style transistors again. They have gone full circle on their output design. The "rear Heatsink" models are no longer in production. The same model CA-200 is available pre 2002 with rear heatsink set up. The newer model went to more output devices with side heatsinks. I called classe and they said the new models control bass a bit better and the older style are a "Tad" warmer.
