Posted 27 July 2012 - 04:00 PM
The CTS4200 has a Clip light on: This may indicate two things: either the amp is clipping normally or the amp is limitting (thermal condition). We'll go with the assumption that the signals are appropriate and of program material (NOT SINE GENERATED!). Verify that the loads (min 4 ohms in dual, 8 ohms bridge, distributed) are appropriate for the output (speakers or distributed). Reduce input levels until the Clip condition is removed (cool unit off). Then, bring input levels until you start to have Clip events and reduce levels until no more Clip is seen and bring down the levels a notch.
Same thing for the CTS1200: Hopefully you're not testing with Sine! That doesn't bode well with SMPS supplies. There areoutput Thermal and Clip events that must limit output current and input signals to the max! Again, start off by reducing input levels and cool off the amp. Then gradually increase levels until Clips events start to appear and reduce levels until no more Clips are seen. Then reduce one notch.
There is a new calibration protocol for the JTS circuit (CTS1200) that seems to have a better thermal tolerance. I would perhaps make an appointment with an authorized Crown service center to have the JTS re-calibrated.
Hope this helps!