Equipped with 2 channels and 4 modes, the Blackstar HT Club 40 is the ideal gigging valve amp for club sized venues. The 40-Watt EL34 driven power amplifier has amazing punch and dynamics that will easily cut through in a full band situation. Switching to the ISF equipped overdrive channel accesses a further two modes classic crunch’ and ?super saturated lead’. The Blackstar HT Club 40 is powered by two EL34 power tubes and two ECC83 preamp tubes (which are a European-designated variation of the 12AX7s that are more familiar here in the States). The Clean and Overdrive Channels are footswitchable. The Clean has Volume and Tone controls with a voice switch for what the company describes as “boutique” and “modern” voicings. The Overdrive has Gain and Volume controls, a three-band EQ, Blackstar's Infinite Shape Feature, and a voice switch that offers “classic” (tight and crunchy) and fuller-body voicings. The amp’s front control panel is rounded out with Master Volume and (digital) Reverb controls.The patent-applied-for Infinite Shape Feature: “The ISF control works in conjunction with the Bass, Middle and Treble controls. It allows you to choose the exact tonal signature you prefer. Fully counter-clockwise has a more American characteristic with a tight bottom-end and more aggressive middle, and fully clockwise has a British characteristic which is more ?woody’ and less aggressive.” The rear panel features a Speaker Emulated Output, a Dark/Light control for the Reverb, and an effects loop. The combo weighs in at 54 lbs.