Trinity Class AB - Trinity 504 Quick Specs - Model 504 - Class AB bridgeable Amplifier - RMS – 170W x 2 ch @4 ohms mono - 85 W x 4 ch @2 ohms stereo - 50 W x 4 ch @ 4 ohms stereo * Stable into 4 ohms bridged or 2 ohms load workable * 2 ohms bridged load workable at music playing * matched Bi-Polar output transistors * dual transformer * 12 dB low pass and high pass crossover * 18 dB bass boost equalization variable control * Input sensitivity variable: 7V – 250mV * 3 way protection Circuit: over voltage, speaker short and thermal overload * S/N ratio :> 105dB * THD: <0.1% * size – 9.0” x2.50” x 11.8”