Finally, the Cambridge did a gutsy job with the sound of bassist Tracy Mortimer’s electric bass, which sounds clean, clear, and absolutely thunderous on the Untapped Blues Festival disc. Even though four-string basses don’t reach down into true low-bass territory they are still difficult to reproduce, partly because they have deceptively complex timbres, and partly because they impose abrupt large-scale power demands on amplifiers. The trick is that amplifiers must answer those demands without losing composure or detail in the midrange and treble regions. Even when I cranked up “Let’s Set The Time” to quite invigorating volume levels, the Cambridge took Mortimer’s propulsive bass lines in stride while keeping the rest of the band in sharp focus.
Thus far, we’ve focused on the 840A’s strengths, which are wonderful and exciting, but we should also discuss two areas where the amplifier’s performance is good, but not great. First, the amplifier’s treble response, though clear and well-detailed, is shelved downward a bit, at least relative to the treble regions of some of the more transparent-sounding power amplifiers I’ve heard of late (e.g., the Spectron Musician III or the NuForce Reference 9 Special Edition—both of which cost far more than the Cambridge does). This doesn’t mean the 840A’s highs ever sound “soft” or diffuse, but rather that they are just slightly recessed in the mix.
Second, the 840A fails to achieve the sculptural three-dimensionality that competing integrated amplifiers such as the YBA Designs YA201 provide. Though I would normally call the Cambridge a very detailed amplifier, it tends—for whatever reason—to downplay small sonic cues that can reveal the acoustics of recording venues, and the size, depth and body of instruments. You can maximize the 840A’s performance potential by equipping the amplifier with a good aftermarket power cord (e.g., the Furutech Alpha Reference) and by pairing it with speakers that are inherently strong soundstagers (e.g., the Mirage OMD- 28s). Even so, the French-designed YA201 does a better job of conveying depth and dimensionality. Listening to the 840A is like gazing at a high-resolution photograph, while hearing the YA201 is more like viewing a sculptural object. Good though the photograph may be it never conveys the substance and smooth, continuous shadow detail that the sculpture possesses.
The Azur 840A is beautifully made, and its power, clarity, detail, and life-like dynamics make it a blast to hear. For those ready to embrace the world of multi-zone audio the Cambridge’s flexibility may also prove irresistible. In the areas of dead-neutral treble response and of holographic three-dimensionality, the 840A can be outperformed, but only—in my experience—by amplifiers that cost more. Even taking minor shortcomings into account, I regard the 840A as one of the finest midpriced integrated amplifiers I’ve heard; it consistently conveys the vitality and dynamism of live music. TAS