If youre looking for a toneful all-valve bedroom boogie box but want more than three knobs, the weeniest Blackstar is aimed right at your jugular. Review by Dave Petersen
Blackstar‘s Artisan amps, reviewed in Guitar & Bass last summer, have become firm favourites with a wide variety of players, both famous and less so. The HT-5 is following in their footsteps, but instead of the wide-open plug-in-and-blast applications favoured by the bigger models, it’s catering to the growing demand for very low power valve amps, popular in home studios based on hard-drive recording gear. There’s hot competition from directly-connected PC modellers, but many recording players favour the amp/mic/A-to-D method for its authentic Sun Studios liveliness, even if results are a little less predictable. So small valve amps are very much today’s order of business, and recently bigger amps are also sporting power selectors that allow half-power or less, some going below the one-watt mark.
Far from being a simple single-ended version of the Artisan 15 – which, given the 15’s popularity, it must have been tempting to produce – the HT-5 is a brand new design with some original and interesting technical touches. It incorporates in its preamp much of the circuitry from the HT valve-driven pedal series, coupled to a novel power stage that uses an unusual twin triode push-pull arrangement for power rather than the conventional single-ended pentode power valve. The reason, Blackstar says, is that it sounds closer to a big class AB amp being driven to its limit, and there’s a good deal to support their philosophy. Push-pull has an inherently different harmonic spectrum to single-ended operation in overdrive, and can sound less nasal and narrow-banded. Those seeking clarity without resorting to feedback circuitry often advocate the use of triodes, although these valves demand more from the power supply for a given amount of output power. Interestingly the HT-5 uses an exotic valve, the 12BH7, better known as the power-driver pair in the Ampeg SVT bass amp, in a fixed-bias set-up with a high supply voltage that has fed into the amp’s name. Triodes used as output valves are also notoriously drive-hungry, and Blackstar has adopted a Music Man/Peavey-like configuration of driver transistors to provide enough swing where a conventional driver valve would lack the required oomph.
For a small amp, the HT-5
doesn’t lack ambition. The channel switching arrangement of one clean
and one overdrive channel isn’t unusual, but the four-function EQ with
its conventional tone-stack is augmented by a control marked ISF that
awoke our inner tonehound. Its effect is to shift the overall contour
between an American-style ‘U’ and a more British mid-accented sound,
but it doesn’t work like the Mid control – instead it seems to shift
the centre-frequency of the tone stack, and you can hear a phaser-like
effect as you sweep it manually. There’s also a phone jack with a
selection of cabinet types.
The rear panel offers a
level-switchable effects loop, series-wired upstream of the tone stack,
which can thus be used to filter the post-effect sound. A small quirk
is that the loop is wired between the Gain and Volume controls when the
amp is in overdrive mode, so that the effects are included in the
saturation chain. This could be difficult to deal with or an
opportunity for creativity, according to your temperament. Results
would vary according to the individual effects in use.
on, and nothing is audible but a very low level buzz from the
transformer. The preamp is gated off, but there’s no need because even
with a guitar connected there’s no noise to concern even the pickiest
recording engineer. The Clean channel volume needs to be advanced to
around half to get room level with a Strat, so we’re not dealing with Fender Deluxe
early saturation, and at full volume the level is lively and recordable
but wouldn’t upset a drummer. The sound is clean, open and bright, and Fender users may well want to fill in with the Bass control.
tone bands are nicely tuned without much overlap or interaction, and
the ISF control sweeps the contour from twangy and riff-friendly
through neutral to bluesy and woody. We had fun using it to emphasise a
guitar’s tonal peaks rather than squashing them – the SG with full Brit on the ISF becomes a smooth George Benson-style jazzer, while the Strat with minimum (US) settings does a mean Robbie Robertson clank, morphing into a woody mid-pickup warmth on British – think Toe Tapper by the Shads.
switching to Overdrive gives us the full range of the well-received HT
overdrive pedal, with its drive smoothly adjustable from clean but
aggressive to legato super-sustain. One standout HT-5 trick is the
SG/overdrive/maximum ISF sound – it drives like a fuzz through a wah
stuck on its low range. A quick check of the phone socket confirms
clear and pleasingly unfizzy lo-fi performance, with a perceptible drop
in bass when selecting 2×12 cab contour after listening on 4×12.