Turns out, the Classic 300 is a tube amp in all its glowing glory, but Markbass integrated some characteristically clever technology to improve on the archetypal concept. Similarly, the CL 108 is an 8x10, but its neo speakers and compact design represent a distinctly modern take on the old back-busting fridge. The Classic 300 includes a “Microcontrolled Amp Management System” that controls important parameters in the head and gives a real-time readout of a variety of components’ operational status. In doing so, Markbass has addressed the primary concerns most modern players have with tube heads: they’re temperamental, require periodic maintenance, and blow tubes with little warning. The system’s LCD display doubles as a digital VU meter and general informational readout when its diagnostic functions aren’t in use.
Classic 300
Unfortunately, Markbass didn’t provide me with a schematic, so I’ll have to make some guesses as to the amp’s architecture. Taking a peak inside the chassis revealed a fair smattering of transistors in what looked to be the preamp section, so I’d bet some elements of the EQ and gain staging are solid state. Excepting the microprocessor, the Classic 300 is a fairly straightforward Class AB design, with ECC99 phase-inverter and driver tubes fronting six KT88s. Although KT88s are often thought of as the European equivalent to the American 6550 (as found in Ampeg SVTs, for example) they differ in substantive ways, particularly KT88s’ capacity for higher plate voltage and anode dissipation (power output). In practice, the differences are subtle, although there is an audiophile constituency that thinks KT88s are slightly higher fidelity than 6550s.
The Classic 300 was well built and felt rugged, plus it looks the part, with a front-panel vented stout case, hardy steel corners, and little bits of flair, like Markbass’s trademark yellow text and piping. In addition to the simple EQ controls, the front panel also presents the standby and bias switches. The bias switch is an excellent illustration of the microprocessor’s myriad benefits. With it, the player selects between high fidelity and long life mode. When power tubes are biased to allow high plate dissipation, they operate in a more linear relationship to the input signal, resulting in less distortion, but shortening the tubes’ life because they’re operating near their meltdown point. By contrast, biasing a tube “cold” extends tube life, but the resulting sound is more distorted in comparison to a “hot” bias. Since the Classic 300 biases at each power cycle, it checks the real-time bias condition and allows the player to choose. In practice, the two settings don’t sound all that different, but there’s a bit more clarity in the high fidelity position, so in critical settings, it’s probably the better option.
The Classic’s 4-band EQ is a simple as it gets, but even so, it’s a bit unusual. Whereas most such systems utilize shelving filters at the opposite extremes of the audio spectrum, the Classic uses notch filters centered at low and high frequencies, so a boost or cut at either end doesn’t affect all the frequencies above or below the filter’s knee. The result? A bass boost didn’t yield much muddiness, and treble added sparkle, but not super-extended sheen.
The Classic 300 sounded buttery and thick, but not congested. Its unmistakably syrupy attack was tube-y indeed, but it was still dynamically sensitive and responsive to transients. Paired with the CL 108 8x10 it was easily capable of volume enough for any stage. It’s naturally a bit hirsute, with a furry edge to high-volume notes, but for dramatic effect, the preamp can be pushed into clipping by playing with the gain/master volume balance. True-to-form, low-frequency response was admirably big and lumpy, but it’s not the hugest sounding tube head—more rich and detailed than others, with a colorful midrange and balanced response.
Street $2,499
Pros Killer all-tube head with smart features that greatly enhance reliability.
Cons None
Bottom Line For a pleasantly postmodern mix of new and old, with sweet tone, look no further.
CL 108
Weight-saving neodymium speakers find an excellent home in 8x10s, which are inherently bulky and heavy. The CL 108 is the cutest little 8x10 I’ve seen, and its light weight is a trip—it felt like someone forgot to install the last four speakers. I dig Mark Bass’s concept with the 108: Save weight with neo, but keep the cab sealed like an old SVT, adding a defeatable tweeter for the cats that like a little tinkle in their low-end tickle.
The 108’s construction was solid, although a skid plate would better contend with the countless stairs and boot-toes it’ll inevitably confront in its unceremonious life. The major top handle and caster—coupled with the crazy light weight—made huffing it around no big whoop.
The 108 sounded like a slightly less wallop-y version of its obvious competitor. But what it loses in sheer intestinal disrupt-itude, it makes up for with a scintillatingly speedy attack and taut bottom. Its focused note envelope highlighted its well-developed midrange, accenting the 108’s sublime clarity and pitch definition. The stage spread was still large—as was its sound pressure level capability—but the 108 spoke evenly throughout the room.
The Classic 300 and CL 108 rig is a natural evolutionary step in tube amp design. Coupling modern diagnostic technology to a design that screams for automated maintenance just makes sense, and the resulting setup loses no mojo but gains tons of reliability and gives peace of mind.
Street $1,449
Pros An 8x10 that won’t punish you after the gig.
Cons Not the low-end king, but close.
Bottom Line If you must have an 8x10, and you actually care about your spinal column, it’s the only option.
CONTACT
(416) 763-1493
www.markbass.com
TECH SPECS
Classic 300
Power rating 300 watts rms into 4Ω or 2Ω; 175 watts rms into 8Ω
Input impedance 500kΩ
Tone controls low: ±12dB @ 80Hz; mid low: ±12dB @ 400Hz; mid high: ±12dB @ 800Hz; high: ±12dB @ 3kHz xlr direct interface output Differential op-amp driven with ground lift switch
Power amp topology Class AB
Weight 48 lbs
CL 108 8x10 Cabinet
Type 8x10 + tweeter, sealed
Frequency response 54Hz–20kHz
Power handling 1,200 watts rms
Impedance 8Ω
Sensitivity 103dB SPL (1W/1M)
Speakers 10"
Weight 90 lbs
Made in Italy
Warranty Two years limited
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