SC200 Power Amplifier Behavior With Capacitive Loads and High-Frequency Oscillation

I read the spec on the SC200 amplifier and looked at the frequency response plot, which showed it was flat to roughly 50 kHz with a slight roll off to 100 kHz.
My question is, is this amplifier sensitive to loads that have significant capacitance?  My experience with these kinds of amplifiers is that some will go into high frequency oscillation when connected to loads that have some capacitance, and sometimes the capacitance and the resulting oscillation cause the amplifier to fail.
I know of a commercial amplifier that had a 3 db point at 70 kHz, and when loaded with speakers connected with shielded cable, oscillated somewhere near the frequency of 70 kHz.

Kenneth Ciszewski

Kenneth I am not up to doing fancy analysis of this sort of problem.  But one thing I have seen fairly often is a capacitor in series with a resistor across the output (ie the speaker terminals) of amplifiers.  The resistor is usually comparable with the speaker impedance that the amp is designed for (say around 8-10 ohms) and the cap will start coming into play at the highest frequencies that the amp is required to output.  A 1uF cap will be 8 ohms at 20KHz, a bit over 2 ohms at 70K.  So at 70K you'd effectively have a low resistance across the output which should damp oscillations of this sort.  Not guaranteed to work but a quick easy possible solution to try.

I'm aware of this method of changing the high frequency roll off. I was just wondering if anyone had come across this particular problem.

Oh, and make your 10 ohm resistor fairly beefy.  If the amp is putting out 200W at 20KHz it will take a fair bit of power.  In normal use this would not occur, but in testing it might.  Put the cap and the resistor directly across the speaker terminals.