Blackstar is a relatively new British company, launching in 2007, that boasts an R&D and engineering team that cut its teeth with perhaps the biggest amp name of all time: Marshall. Breaking out on their own in this new venture, Blackstar has its own range of range of amps as well as various valve-driven pedals. They're all devoted to that most satisfying of pursuits: distortion and drive.
The pedals share various features. Each is loaded with a single Russian-made ECC83 dual-triode preamp valve, backlit to glow red. More interestingly, that valve runs off a full 300-volt circuit, (hence HT in the name: HT for 'high-tension' meaning high voltage). This is thought by many to offer better tone, gain and overload characteristics than low-voltage valve pedals. After that, all except the HT-Boost offer a speaker-emulated out alongside the regular output for a direct-to-desk recording option, and finally, three of the quintet are loaded with what's called an ISF (Infinite Shape Feature) control. Unlike more familiar contour circuits, this enables you to move the entire EQ section voicing between what you'd expect of two classic amplifier tone circuits: Fender at one end and Marshall at the other.
"The ISF came about because we were looking for a way to voice testbed amplifiers for artists," explains Blackstar's technical director, Bruce Keir. "We needed a way to continuously vary the tone beyond what was available from existing amplifiers. This would enable the player to create their signature sound before we 'locked it off' in their preferred setting. The method we came up with gave the ability to not only get the standard reference tones, but also the 'in-between' never-before-attainable voicings as well. It worked so effectively and so simply that we decided to make it a feature available for all guitarists to use." Indeed, the ISF control broadly apes the tonal response of classic 6L6- or EL34-powered amps, plus many points in between. You'll find the other pedals reviewed on MusicRadar, but on test here is the HT-Dual DS-2
As its name suggests, this unit offers a pair of distortion pedals in a single chassis that are available via two channels, each with its own footswitch. The three tone controls plus the ISF pot are all master controls, while channel one has both clean and crunch modes, against channel two's single mode. Independent gain and volume regulators mean you can balance the two channels precisely to your needs.
Channel two offers a smooth, fluid drive that spans a meaty rock rhythm tone to a full-on searing lead. The overall frequency response is wide, so this is no nasal, mid-heavy screamer. The drives clean up well as you roll your guitar's volume back too. Channel one has a much wider range of gain thanks to its dual modes; a near-clean boost, through to a fuller, smooth drive.
The ISF pot is also a winner. It's relatively more punchy and cutting at one end, or thicker and more loose at the other - and everything between. The only downside is that it isn't obvious how to bypass the pedal; in fact, you press the activated switch a second time.
Still, as a way of turning your single-channel amp into a three-sound fire-breather, this is pretty special.