The Hartke HA2500 Bass Amp Head has a unique tube-emulation/solid-state circuit which faithfully reproduces every nuance of your bass performance with excellent clarity and punch. Ideal for live performance use in small and medium-size venues the Hartke HA2500 delivers 250 watts of power to a 4-ohm speaker system or 180 watts to an 8-ohm speaker system. Offering a number of advanced features including a 10-band graphic EQ High Pass and Low Pass contour knobs and a built-in compressor the Hartke Bass Amp Head provides outstanding tone-shaping for a range of musical styles. The Effects Send and Return jacks allow you to connect the HA2500 amp head to professional outboard effects processors while the effects balance control enables you to adjust the relative amount of send and return signal being routed to the speaker outputs. The silver-face chassis adds a clean stylish aesthetic to any setup while the rugged construction ensures the HA2500 is roadworthy and reliable. Additionally the advanced preamp features mean this amplifier head is suitable for use in studio performances too. Features 250 watts output at 4 ohms and 180 watts output at 8 ohms Tube-emulation and solid-state preamp circuit 10-band graphic EQ High Pass and Low Pass contour controls Built-in compressor Active and Passive inputs Protection relay circuitry Effects loop Send and Return jacks Unbalanced 1/4 speaker outputs Balanced direct out with ground lift and pre/post switches Rugged and roadworthy construction Specifications Input Sensitivity: Passive Input: 100k Ω 20 mv Active Input: 100k Ω 60 mv Rated Output Power: 250 Watts at 4Ω 180 Watts at 8Ω Total Harmonic Distortion: < 0.5% Equalizer: ±15 dB Center Detented at 30Hz 64Hz 125Hz 250Hz 500Hz 1kHz 2kHz 3kHz 5kHz 8kHz Contour Low Pass: ±18 dB at 100Hz Contour High Pass: ±18 dB at 10kHz Compression Ratio: 2:1 to Infinity