Click on the Photo Above to See a Larger Version
Power: 400 Watts RMS x 7, 20 Hz -
MFR: 1 Hz - 80 kHz
Current Source and Voltage Source
XLR and RCA Inputs
Size: 6.5" H x 19" W x 15.75" D
Weight: 52 Pounds
MSRP: $3,995 USA
I first became aware of Bob Carver and his Carver products back when I was
in High School overseas. The only affordable source of electronics was the
Exchange on base and needless to say, the selection was very limited.
Mainly you could choose from some very low end receivers at the time. But
this wasn't really the era of affordable home theater.
The Exchange did carry a few select products that were a bit better then
the norm though. For speakers there were some nice offerings from JBL. But for components, the only higher end example was Carver. I
personally couldn't afford it on my Burger King salary at the time, but I
had a friend who was using Carver separates to power a pair of Bose 901s
which at the time were the elite, well at least to my limited knowledge.
As most of you know, Bob went another direction later and established
a dedicated line of home theater products under the name Sunfire. The
Carver line is still produced, but it deals mainly with commercial
applications, or so I'm told.
Under the Sunfire line came some very well regarded processors and
amplifiers featuring some seldom used technologies, even by today's
standards. Bob has carved somewhat of a niche market with his designs, and
we at Secrets have truly admired his efforts since our start. His
processors and amplifiers have received a lot of praise from our reviewers
and rightly so.
For this review, I was sent the new Cinema Seven Signature Edition
amplifier. This amplifier is similar to Sunfire's previous offerings
in that it uses a Class D switching power supply, making it very
efficient. It is also a workhorse of rare breed offering an unprecedented
400 Watts per channel into no less then seven channels, all channels
driven!! This kind of
power is an extreme rarity unless you're looking at products the size of
end tables with enough heat output to keep an Alaskan town warm. What is
even more amazing is the fact that the amplifier doubles its output each
time you halve the load impedance. Sunfire claims this amplifier can
actually produce 1,600 Watts per channel into 2 ohms on a limited time
basis. I was unable to test this theory, as I don't have any 2 ohm
speakers hanging around, unfortunately.
As we have mentioned in previous reviews of Sunfire's amplifiers, this
kind of power is due to the tracking down converter Bob has developed.
Most amplifiers keep their rail voltages at a constant level, so unused
voltages can create a heat buildup. The Sunfire takes samples of the signal voltage and keeps the
rail voltage just slightly above that.
During dynamic shifts, the voltage
may have a hard time keeping up. But the Sunfire sounds excellent, and I never heard any noticeable distortion in my
time with the amplifier.
Another advantage to digital switching amplifiers is cost. Sunfire's designs give you
incredible amounts of power without an incredible price tag, and the
Cinema Seven Signature will drive any set of speakers you might have,
The Cinema Seven casing is machined aluminum and is roughly the
dimensions of most processors. The front panel features a meter that
indicates the current joule rating of the capacitors. This gives you an
idea of the stored power the amplifier has. The meter is illuminated and
gives the amp a bit of an old fashioned look. The lighting is adjustable so
those looking for absolute lighting control in their room have no worries.
For the Signature Edition the meter reads 480 joules. I never once saw it
drop below that at any time, even while running my setup at full
The back panel has a very nice layout, making connections fairly easy. The
binding posts are 5-way and are very solid. Each input features three
connection options, two RCA unbalanced and one XLR balanced.
The Sunfire is not a truly balanced design but if your processor has XLR
outputs, you can use them with the Cinema Seven.
Click on the Photo Above to See a Larger Version
Like previous Sunfire amplifiers, you have a choice of
voltage source or current source outputs, selectable by choosing which set
of speaker binding posts you connect to. The principle is based on classic tube
amplifiers being current source by design. According to Bob, this gave them their trademark
sound, which was warmer and a bit more full bodied than the voltage source
designs of most solid state amps used today. Bob wanted the flexibility of
offering a choice depending on your taste in sound. Those with
electrostatic or ribbon speakers may opt to use the current source
connection, while others may use the conventional voltage source
outputs. You can also drive separate parts of
your speakers with the different output types, e.g., drive the
woofers with the voltage source and the tweeters with the current source. This is the recommendation Bob gives for
setup in the manual, and I gave it a try. I'll talk more about that
in the listening section of the review.
Last up on the back panel is the power switch, which has settings for On,
Off, and Auto. Auto will turn the amp on when it senses a load. This
was the setting I used most of the time and the delay once a signal is
detected was only about 1-2 seconds. There is also a 12V trigger input so
that the amplifier can be powered on from a processor or
The amplifier comes with a glass plate for placement underneath. This
plate has more functions than just looks. First it allows proper room beneath the
amp for ventilation. It also serves as a vibration damper for those choosing
to set the amp on a component rack.
I started my listening for the first week or so with strictly home theater
use. I wanted to break the amp in a bit with more dynamic tracks and then
work into music. The amplifier I was using prior to this one was the Krell
Showcase amp which I found very satisfying.
The Sunfire actually upped the
ante a bit with film soundtrack reproduction. The soundstage increased a
bit and the amp seemed to give my speakers a bit more transparency then
the Krell did. This may be attributed to the power increase, as the Sunfire
has more then double the power. The Sunfire never so much as batted an eye
at any DVD I threw at it. This is pretty much what I would expect as my
speakers are fairly efficient (92 - 93 dB) and only a 6 ohm load. I also have
them crossed over at 80 Hz providing a relatively simple task for an
amplifier of this magnitude.
The Sunfire has a relatively high distortion rating compared to most Class
A/B amplifiers due to its tracking design (0.5% THD).
This never appeared to be a problem, as the amp sounded every bit as good
as anything I had heard before it. The soundstage was rich, powerful, and
very transparent. It continually impressed me regardless of
genre and sound design, enough that I started conspiring how I could get
my wife to agree to let me add it to my system. This is an amplifier that
I would easily consider as a reference piece in a home theater system.
After a week or so, I started delving more into music, both multi-channel
and stereo listening. The Sunfire provided a spectacular
sound that was very neutral and very engaging. Most of my listening
involved high resolution DVD-Audio, and the Sunfire performed brilliantly.
I never heard any audible coloration in the midrange, and the higher end of
the spectrum sounded very detailed and rich.
After listening to music for a few days, I decided to experiment with the different output configurations of the amplifier. At
first I drove the speakers using the standard voltage source outputs. This
provided the sound I was more accustomed to and was by far my preferred
setup. I thought the amplifier performed its best in this configuration
especially in the low end. When driving my speakers full range with two-channel material, this configuration provided the most dynamic experience
with tighter more detailed bass, and was evident more in jazz and hard
rock. Kick drums and lower bass notes had more report to them. However, this area
is the only spot in which I thought the Krell outperformed the Sunfire. The Krell had a low end that was extremely impressive. Using the Krell with my
speakers resulted in bass that would almost make a subwoofer
unnecessary. The Sunfire did provide plenty of low end power; it just
wasn't quite as involving as the Krell was. But this wasn't much of an
issue with me, as I rarely ever run my speakers full range.
When I switched to current source, I immediately noticed the change in
tonal quality. This mode is used to coax a more tube-like sound from the
amplifier. It did offer a slightly more laid back sound, but it wasn't
really to my liking. I found the lower end a bit too subtle. There have
only been a few times that I have preferred a tube sound, and that is
mainly in guitar amps with certain types of music. A good example of this
is Eric Johnson's music. The richness of his playing is fully complimented
by the tube amplifier he uses.
I also tried using the voltage source for
the woofers and the current source for the tweeters. This was more enjoyable
than going all out current source. The soundstage was more
defined, and the lower end regained the tighter more pronounced feel. This
was more apparent in music playback than film soundtracks though. While I
did prefer straight voltage source overall, I love the idea of offering
the end user a choice and leaving it up to his/her ears.
Sunfire has yet again produced an excellent amplifier that sets a new
benchmark for price/performance. I was very reluctant to give the amplifier
up at the end of the review, as I had really enjoyed my time with it. It is
easily the best amplifier overall that I have had the pleasure of having
in my system. For those looking for extreme power and excellent sound,
this is an amplifier you should definitely audition.
- Kris Deering -
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