Tube Power Amp Reviews

The standard-edition Wavelength Audio Cardinal is priced at a mere $5250/pair. Each monoblock uses a 5AR4 to rectify the high voltage for the plate supply, a 6SL7 in the gain/driver, and a single 300B output tube. Brown-bottomed Golden Dragon 300Bs are standard. Various tube choices are available from the manufacturer, including original Mullard 5AR4s. The power is rated at 7+ watts per channel (Wpc).

Let's see...$5250/pair divided by two, divided by 7. That's $350 per watt per channel. We're talking bargain here, compared to Jadis.

Of course, there are ways to spend more. You could get the Wavelength Cardinal XS for $7500/pair. The "XS" stands for extra special. (I thought it stood for excess.) J-10 reviews this version elsewhere in this issue. You could also order your Cards in exotic woods rather than the standard curly maple, cherry, or walnut. But if you do, beware: Gordon Rankin, the manufacturer, will penalize you!

"It is possible to get the amplifiers in more Exotic [sic] woods with the following understanding: We believe that the woods we have selected are replenished by todays [sic] ecological laws. Woods from the rain forest will simply degrade our planet. For this reason the cost for any of these is as follows: The cost for the cabinets plus $1000 dollars that is donated to the preservations [sic] of the Rain Forest fund."

Me? I'd never want to deplete a rain forest. But I wonder whether paying an extra "$1000 dollars" makes it right to become a consumer of endangered wood, even if the money is donated to the Rain Forest Fund. Suppose I want to hunt and kill a rhinoceros—or an elephant for its ivory. Is this okay if I pay "$1000 dollars" to Save the Elephants, or whatever? And who gets the tax deduction—Gordon Rankin or the customer?

Back to the amps.

They look...homemade, especially compared to the Jadis SE300Bs. Maybe the exotic rain-forest finishes would help. And guess what? The amps are "homemade" in the sense that each one is personally built by Gordon Rankin himself. No doubt this is one of the things that pushes up the price.

How do they sound?

Glorious. Maybe a little too glorious, but glorious nonetheless. These are among the most musical amplifiers I've ever had the opportunity to listen to. Yes, I do prefer the Jadis SE300Bs, at more than twice the price, but the Wavelength Cardinals make a powerful statement.

The Cardies may have only 7+Wpc, but they did surprisingly well driving a pair of Castle Durham 900s. They even drove a pair of Thiel CS.5 speakers to reasonable, if not quite acceptable, levels.

The most surprising thing, for me, is the bass. It sounds powerful. This is not one of those light and airy 300B-based amps that sound very open and fast but don't have any balls down below. The Cardinals have very convincing bass performance indeed—full, rich, well-defined, extended. The bass could be tighter and faster, though. The Cardinals sound very much like the tube-regulated amps they are.

Of course, if you crank up the volume too high, you lose it. The amps clip—not disastrously, but clip they do. Distortion sets in, but most of all dynamics are compressed. When all is said and done, 7+W is still 7+W, and, with most speakers, there may be times when you want more. I did.

Here's where I disagree with the manufacturer, who says that speakers with a sensitivity rating as low as 88dB are "plenty efficient" for this amplifier. Based on my experience? Not unless you want to listen at very low levels and are willing to sacrifice dynamics.

This dilemma faces all of us who are into 300B amps—or at least, those of us who are into most 300B-based amps. The sound may be exquisite—detailed, delicate, harmonically pure. But the dynamic drive isn't there.

I wish I'd had some more-efficient speakers on hand to try while I had the Cardinals in-house. For the most part I used the Castle Durham 900s (not the last word in transparency, but easy to drive) and the Thiel CS.5s (more transparent than the Castles, less easy to drive). So long as I didn't crank up the volume too high, the Cardinal's 7+W sounded more powerful than I would have imagined, even with the Thiel CS.5s.

At their best, when not pushed, the Wavelength Cardinals have a beauty of timbre and a purity of tone that few other amplifiers can match. Voices, pianos, and woodwind instruments, in particular, can take on a beauty which is ravishing. So can cellos, which benefit from the generous, rich, ample bass (so long as the amps aren't pushed).

What the amps appear to lack (aside from power) is speed. The Cardinals, in my auditioning, tended to sound just a wee bit slow. The amplifiers didn't let go of the notes the way that some amplifiers do—the Jadis SE300B, for instance. I think this lack of speed is mostly a bass thing. Also, the treble sounded rolled-off. (Tube-swapping, particularly with the 300B, can probably fix this.) The midrange, though, like the bass, was rich, ripe, downright glorious.

On the right speakers, these amps might be killers. Too bad I received the lean-sounding Infinity Composition Prelude P-FRs after I'd sent back the Cardinals: with their 96dB-rated sensitivity, the Cards might have been a perfect match for these speakers. As Bob Harley noted, the Compositions lack "weight and authority." The Cardinals have weight and authority—as I said, surprisingly so for a 7+Wpc amp.

As it is, I can give the Cardinals a qualified recommendation. The sound—so long as the amps aren't pushed—is clean, pure, and harmonically rich at all times. Especially compared to the Jadis SE300Bs, the Cardinals displayed a lack of air and a lack of ultimate low-level resolution...but the Jadis amps cost much more. Possibly you get that extra air and resolution with the $7500/pair excesses—I mean XSes. We'll have to see what J-10 says.

Don't get me wrong. I enjoyed the Cardinals very much. I think it's great that amplifiers are being made that give audiophiles an alternative to the usual tube-and-transistor monsters. There is something good—very good—going on here, especially with regard to truth of timbre. These amps have a harmonic beauty, a richness that is quite special. Are they accurate? Who cares?

"These amps are pleasure machines," said one audiophile, after hearing the Cardinals at my place.

What's wrong with that? (One gets the impression, reading JA's recent comments about single-ended amps, that listening for pleasure, at least for reviewers, is a no-no. John...?)—Sam Tellig