Check the listing for details. ENGL Amplifiers Poweramp 50/50 E840 Rackmount Power Amplifier. Condition: New. Listed at 1650.00 USD. Pro-level Power for Your Rackmount Rig The perfect centerpiece for any rack-based guitar rig, the ENGL Amplifiers Poweramp 50/50 E840 is a 100-watt, 2-channel rackmount guitar power amplifier with much to offer. The E840 comes loaded with four 6L6GC power tubes and three ECC83/12AX7 preamp tubes, offering rich overtones, optimal attack, and ample headroom for every application. You get per-channel Presence controls for maximum tweakability, along with A and B Volume controls, enabling you to call up two different volumes with individual sonic characteristics. The guitarists here at Sweetwater also appreciate the E840's footswitchable operation. High-level players with professional guitar racks need a pro-level power amplifier, and the ENGL Poweramp 50/50 E840 more than delivers.