PLD 4.2 Input Clip Before Output Limit

Max Warasila

Feb 20, 2013
Richmond, VA
Hi, all!

I'm having a strange issue with the QSC PLD 4.2 amplifier we are using to drive 4 Danley Nano Cubes for a theatrical production. For some reason, the input clips long before the output even reaches the limiter, which is kind of wild in my mind, since the Nano's are limited at 20W/12V RMS. Additionally, the output only increases a few dB when the input goes from -20dB to clipping on the display. Does anyone have any idea what's going on? I'm totally at a loss and about to just call QSC before I lose my mind.

Also, quite strangely, the Nanos are reading with an input impedance of above 20 ohms, which seems higher than what I should expect from power compression, but maybe I'm wrong? Let me know if that's about right. It's not something I've really looked into before.

Thanks in advance!