"bsguidry" wrote in message
om...
[snip]
, or not finding the right ratings lists.

Good brands to look at include QSC, Hafler, and Crown. If you surf the
vendor web sites, you'll find very detailed RMS power specs.

Take QSC off the list. It's a testament to Arny's hearing difficulties.
Othewise, I concur.

I've definitely consider QSC and Crown, however, I've not encountered
Hafler very often in my searching.

David Hafler invented the Ultralinear tube circuit, which firmly enshrines
him in the audio pantheon of greats. He became chief engineer of Dynaco, and
went on to start Hafler. His second product was the DH-200, the world's
first MOSFET audio amplifier. At the time, this amp was regarded as a
price/performance breakthrough. Unassuming in appearance, it has massive
heatsinks with very plain metalwork. It was followed by some extremely good
preamps, and more MOSFET amps, some of which had a new circuit, the
Excelinear.

MOSFET amps are the most durable of all solid state amplifiers. They can
drive any load without output damage, and if you're reasonably lucky, they
will survive a dead short. The MOSFET transistor is now ubiquitous in power
switching applications because of it's ruggedness.

The sound of the traditional MOSFET circuit has both followers and
detractors, to which I add my personal observation that they complement
metal dome tweeters very well, but are not as good with fabric types.
Another MOSFET circuit developed by Jim Strickland, founder of Acoustat,
provides a different kind of sound that compliments fabric tweeters. I use
both types of amplifiers in my systems, depending upon the speakers they
match. At the time of it's introduction, the Acoustat TNT-200 was featured
on the cover of Audio Magazine, and it was regarded by many, at that time,
as raising the bar for clarity and detail in reproduction.

When Rockford bought Hafler and Acoustat, they chose -- unfortunately, in my
opinion, to preserve only one amplifier technology. Strickland's original
design was hardened -- the original design had vulnerabilities that had
nothing to do with output load -- and launched the 9000 series, and the P
series professional amps. These are astonishingly small, extremely high
quality amplifiers that are far tougher than the typical professional unit.
Because they use MOSFETs, they have no relays or fuses, and in my opinion,
have MUCH higher fidelity than the QSC units. Both types of Haflers are
common in studios, the XL-600 being one of t he most prized units. I have a
P3000.

Every once in a while, I find something really remarkable, or at least
remarkable for the price. I also use the Parasound HCA-2200ii bipolar amp. I
have found the Yamaha bipolar M series to have merit, though the build
quality is not in the class of an American amplifier. Nelson Pass's
Threshold amplifiers can be found in some Nakamichi receivers, and are quite
a pleasant surprise. B&K amplifiers use the traditional MOSFET circuit, with
exceptional build quality. I do not particularly enjoy ADCOM MOSFET amps,
though the build quality is very high.

I found the sound of Rotel, touted by various audio magazines, to be
disappointingly shrill.

The QSC is muddy. It's performance is a throwback to the bipolar amplifiers
of the late 70's and early 80's.