One of GB's greatest designs (and award-winning), this head combines an all tube driven pre-amp with a solid-state backend to deliver 600 watts of blistering bass punch and tone. This head is in great shape and never gigged, used primarily for silent home practice (another cool feature with audio and in and headphone out jacks) and some band practice sessions. It is super lightweight at only 6 lbs so transporting it is a breeze.
This from GB:
The Streamliner 600 STM-600 is Genz-Benz's 600-watt version of the Streamliner design. The Streamliner 600 has a 300 volt All Tube Class A preamp design is driven by three 12AX7 preamp tubes utilizing six gain stages. The preamp design features an intuitive and highly effective tone network which is a unique blend of a modified passive Baxandall network for the bass and treble along with an active tube driven mid filter, with selectable mid frequencies. This versatile all tube preamp exudes a fat and rich tone that remains articulate. It can be used to simply add warmth to your natural tone, or it can be dialed in to provide a wide range of natural tube overdrive.
Along with Genz-Benz preamp design that rivals that of many classic tube amplifiers, the Streamliner 600 also features Genz Benz's proprietary 3-Dimensional Power Management analog technology. Genz-Benz's 3DPM adds heft and girth to each individual note, while enhancing the amplifiers responsiveness and headroom. The Genz-Benz Streamliner 600 also provides the dynamic and 3-dimensional tone and feel of an all-tube power amp design.
With its solid extruded aluminum panels, CNC machined solid billet aluminum faceplate and smooth-radius edges the Genz-Benz Streamliner 600 chassis emanates the ruggedness and strength of a world-class touring machine. This brushed aluminum chassis is finished in an anodized Gun Metal Blue color.