PRS HDRX 50 Head Features: 50W tube guitar amplifier head based on a vintage British non-master-volume amplifier Heavily inspired by Jimi Hendrix's Woodstock-era amp Late-1960s tube configuration: 3 JJ ECC803S preamp tubes; 2 New Sensor EL34EH power tubes Custom-designed Straight Edge output transformer lends an in-your-face quality to your playing 100W power supply mirrors the sound of the original 100W amplifier Incredible dynamic range — achieve everything from clean chime to crunchy grime by altering picking pressure Updated power supply and filament design safeguards against unwanted hum and hiss Familiar 3-band equalizer gives you ample tone shaping 3-way bright switch and High Mid Gain switch offer further sonic customization Presence control for dialing in your upper harmonics Internally bridged channels eliminates the need for external jumping Per-channel Volume controls for easy blending of channels