Hi johnwholst,

In the CTS4200 and CTS8200 and I think the CTS600 (don't remember, can check tomorrow) there are 12V fans. I do not have a CTS2000. Check for Papst brand fan's, they are the best in my view. They should carry 24v fans.

If the airflow is noisy in the back you can also try to cut out the staped mesh in the rear of the amp and mount a round standard computer fan protector on the outside. They won't make any noice. I have done that in a few installation where the square stamped mesh in the back created noise.

Kind regards
//RoB