Ampeg PF-50T Bass Head, Electric Bass Head, All-tube amplifier, Power: 50 W @ 4 or 8 Ohm, 2 Preamp tubes 12AX7, 1 Power amp tube 12AU7, 2 Power amp tubes 6L6, 2 Inputs: 0 db and -15 db, Controls: Bass, mid and treble, 5-Step control for mids, Ultra hi/lo boosts, Input gain control, Pre/Post EQ, Ground Lift, Transformer balanced line out, Ideal for studio applications as load resistance (speaker) is not required, Adjustable bias controls, Dimensions: 382 x 190 x 260 mm, Weight: 8.8 kg