BC Audio’s No. 10 Mk. II is company founder Bruce Clement’s ode to 50-watt British amplifiers of yesteryear. But while No. 10’s appearance is clearly influenced by older Marshall plexis, it’s not a straight clone. Its circuit departs from the original formula in several ways, notably in its 6SL7-based preamp section. The result is a fire-breathing 50-watt beast that generates power tube-like saturation at relatively manageable volumes.
Loud and Proud
At the heart of the No. 10 is a beautiful all-tube circuit, hand-wired point-to-point using top-shelf components. Two EL34 power tubes provide 50 watts of power. But instead of ubiquitous 12AX7-type preamp tubes, the No. 10 relies on four octal 6SL7 tubes. These, according to BC Audio, provide more open-sounding compression and more even-order harmonics when pushed into overdrive. The goal is smooth overdrive akin to a cranked plexi, minus the ear-bleeding levels needed to attain power-tube distortion on those amps.
The amp’s lone channel features gain, treble, midrange, bass, volume, presence, and depth controls. There are also footswitchable volume and gain boosts with independent controls and onboard LED indicators. The No. 10 also includes a tube-buffered effect loop with true bypass switching and dedicated send and return controls. The speaker load is switchable between 4, 8, and 16 ohms.
Awaken the Beast
As its red racing stripe implies, the No. 10 dishes tones with the muscle of a finely tuned late-’60s Shelby Mustang. I connected a Les Paul Custom and a Bogner 2x12 cab, setting the amp gain around 10 o’clock with the mids slightly scooped. Playing bluesy Zep licks, I was floored by how lively and full the amp’s clean tones sounded. The 6SL7 tubes provide plenty of breathing room without congestion or bitter edges. Switching to a Stratocaster, I relished the sparkling harmonics of clean arpeggios and clean-toned Keith Richards-style riffing.
Regardless of guitar type, the No. 10’s tones hit me in the chest more strongly than anticipated. The amp’s delivery simply feels more powerful than equivalent amps with 12AX7s. It almost seemed silly to have an optional volume boost at my disposal, since the amp was far louder than most 50-watters I’ve encountered. Meanwhile, the amp’s attack was less focused, but broader—sort of like the difference between a cut and a hard slap. I wasn’t put off by any means—far from it!—but it takes some getting used to.
When I advanced the gain and midrange controls to 1 o’clock, the No. 10 showed how menacing it can be. The overdrive’s heavy upper-mid emphasis gave my Les Paul an aggressive bite that left few doubts about the amp’s ability to cut through a mix. Alternating between speedy EVH licks and bluesy ’70s riffs, the drive’s grittiness advanced and retreated with a response similar to a fully cranked vintage non-master volume amp. When I backed off the guitar’s volume, the tone thinned out smoothly without compromising its treble bite.
BC Audio’s mighty No. 10 Mk. II delivers voluptuous tones, chest-caving power, and fantastic responsiveness. The build couldn’t be more rugged. The use of 6SN7 preamp tubes enables many cool tones for players seeking something a bit different from the norm. Factor in its user-friendly controls, independent volume and gain boosting, and full-featured effect loop, and the No. 10 is truly a force to be reckoned with.
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