DECEMBER 2004/JANUARY 2005

POWER AMPLIFIERS

JEFF ROWLAND MODEL 201

Dynamite comes in small packages....

The Jeff Rowland Design Group is one of those high-end companies that has unerringly produced esoteric components for as long as I can remember. Renowned for their beautifully finished enclosures and often intricate power supplies, the Jeff Rowland power amps, in particular, have represented sonic nirvana for many.

So, the arrival of a pair of Jeff Rowland monoblocks for review caused a stir of excitement. But when I arrived home one evening to find a compact box containing two tiny power amplifiers, I was somewhat taken aback.

I had been preparing myself for the backbreaking task of maneuvering huge blocks of metal into my listening room. Instead, I found myself gingerly extracting two miniature power amplifiers from their protective velvet bags.

How small is small? Well, each power amplifier measures 292 x 213 x 66 mm (WxDxH), and weighs a comparatively hefty 6 kg. But in every detail of physical execution, the 201s are every inch the high-end units of their larger stable mates.

Thus, the chassis is manufactured from a solid billet of aluminium, which has the added benefit of ensuring immunity from external interference. And that polished faceplate remains a Jeff Rowland hallmark.

A look at the rear panel shows a kettle plug-type power socket, a power on/off switch, a balanced XLR input socket, a pair of unique screw-down binding posts, and a 12V trigger input for remote switch-on. But it's what's under the hood of the monoblock that really matters.

Don't for a second believe that the compact dimensions of the Model 201s suggest a similar limitation in output. Jeff Rowland claims a maximum power delivery of 250 watts into 8 ohms, and 500 watts into 4 ohms.

The spec sheet also reflects a frequency range of 5 Hz to 70 kHz, a current output in excess of 35 Amps, and a dynamic range of 117 dBA. THD is typically less than 0,05%, and specifically 0,006% at 1 kHz. And the Model 201s are stable all the way down to 2 ohms.

To achieve these rather impressive performance statistics, the monoblocks employ an innovative design that makes use of patented power conversion technology quite different from the usual Class D digital amplification. It focuses on modulation and error correction controls via systems dubbed multi-variable enhanced cascade control (MECC) and controlled oscillation modulation (COM).

Without getting too technical, MECC and COM employ much simplified circuitry to precisely and constantly control and error-correct all output section parameters to the benefit of aspects such as distortion, bandwidth and efficiency.

The Model 201s supplied for review were well run in, but I still allowed a good few hours of warm-up before serious listening started. I used the monoblocks in both my stereo reference system, and in an AV role, since the units have been designed to operate in both environments.

In stereo mode, it didn't take long for the Model 201s to make a strong case for themselves. Their penchant for power and control was apparent from the very outset, and they had little trouble taming the notorious Celestion SL700SE Mk IIs I still use as my reference loudspeakers.

The little powerhouses showed off a coherent character that allowed music to be delivered with ample thrust and verve. But there was nothing bombastic nor overbearing about the delivery: the Rowlands did their musical work with engaging enthusiasm.

Tonally, they provided a smooth progression spanning the entire frequency spectrum. The bass was deep and authoritative, creating a rock-solid foundation for the rest of the performance, linking to an expressive, articulate midrange and clean, clear treble.

There was nothing clinical or dispassionate about the way the Model 201s approached the music. Instead, they easily got to grips with everything from Katie Melua to the Buena Vista Social Club, from Bartok to Ryan Adams. Staging was spectacular, thanks in part to a sense of clarity that exposed loads of fine musical information.

For their role in my home theatre system, I employed a set of XLR-to-RCA adapters, and then employed the front channel pre-outputs of the system's AV amplifier to feed the Model 201s.

Once the levels had been tweaked to suit the newcomers, the difference was quite remarkable, with substantial gains in projection and staging, specifically regarding depth, height and vocal clarity. Effects had more oomph, dynamics improved, and there was a greater sense of overall space. The result was a more engaging, more involving movie experience, with enhanced immediacy.

There's no doubt that this is one of the most effective major upgrades to my AV system I've experienced, and one that could be continued on a modular basis by simply adding more Model 201s for the remaining channels. That this would probably start the upgrade ball rolling for the other ancillaries is another issue altogether…

The Jeff Rowland Model 201s are sonic marvels -- beautifully built, embracing obviously clever technology, and delivering performance standards that place them solidly at the esoteric end of the audio road. All the more surprising, therefore, that they don't cost an arm and a leg. At R16 000 a each, value is the final, powerful, persuader.

Deon Schoeman