Performance, after burn-in:
Finally, burn-in is complete. 100 hours of continuous
play has elapsed and it is now time to conduct a critical review.
I began the review process by selecting a dozen Red Book
(standard 16 bit) CD's I'm very familiar with:
Classical:
John Rutter Requiem, Collegium catalog number
COLCD 103
Gustav Holst The Planets, Deutsche Grammophon
catalog number: D164373
A 21 Performance Notes:
John Rutter's Requiem is a wonderful recording and the
large vocal ensemble was beautifully amplified by the A 21. There was space around
each voice and the harmonic interaction was wonderfully portrayed.
Gustav Holst "The Planets" puts every system to
the test. The fourth movement "Jupiter, the Bringer of Jollity" contains
several kettle drum passages that hit you right in the chest. The A 21 did not break
a sweat during the most complex orchestral movements.
Jazz:
Keith Jarrett The Melody At Night With You,
ECM catalog number: 1675
Concord Records Vocal Jazz Sampler, Concord
Records catalog number: CCD-5207-2
Chick Corea Jazz Masters 3, Verve catalog
number: 314 519 820-2
A 21 Performance Notes:
Keith Jarrett's solo piano was the most moving experience
I had with the A 21. The low level detail and delicacy from the A 21 allowed me to
virtually connect with Keith...as if I were sitting right next to him on the piano
bench. Simply outstanding.
The Concord Records sampler contains several performances
by well-known artists such as Carol Sloane, Karrin Allyson, Dennis Rowland, Rosemary
Clooney and others. Just about every track contains an intimate, small ensemble
recording that brings tears to your eyes when listened to on a high resolution system.
The A 21 did not stop the tears...I cried like a baby. That's what high-end
audio is all about.
Chick Corea's 'Lenore' (track 2) on the Jazz Masters 3
album contains killer piano and synthesizer solos as well as super dynamic percussion.
This track should be listened to at moderate volumes to get a feel as to how your
system handles the dynamic contrast between the subdued introduction and the
"meat" of the recording. Simply put: The A 21 kicked
butt.
Folk:
Matt and Shannon Heaton Dearga, Eats Records
catalog number: ESL CD 004
A 21 Performance Notes:
Wonderful guitar and Irish flute recording by Boston based
artists Matt and Shannon Heaton. See their feature on the front page of www.soundreproduction.com . The A 21
superbly reproduced the intimate studio in which this recording was made. The Irish
flute played by Shannon was wonderfully reproduced with a soft yet powerfully articulate
presentation. The guitar played by Shannon's husband Matt is extremely well recorded
with a richness that makes listening to this recording addictive. The A 21 just
loafed along with this album and proved it has what it takes to reproduce such a delicate
recording without introducing any noticeable sonic artifacts.
Contemporary Jazz:
Bela Fleck and the Flecktones Left Of Cool,
WB catalog number: 9362-46896-2
Yellow Jackets Club Nocturne, WB catalog
number: 9362-47031-2
A 21 Performance Notes:
Bele Fleck and the Flecktones produced the "Left Of
Cool" album in 1998 and it's one of the best recordings I've heard (it's an HDCD
encoded disk). The bass lines on track 5 "Let Me Be The One" will show off
your loudspeakers ability to reproduce in-your-face bass slam that's exhilarating to
listen to. The A 21 was outstanding in producing super strong articulate bass lines
over an extremely complex rhythmic background. Wow....
The Yellow Jackets album is used to test upper frequency
transparency with delicately recorded percussion and vocals. The space around each
instrument on each and every track is conveyed beautifully by the A 21.
Pop:
Michael Buble It's Time, 143 records catalog
number: 9362-48946-2
Craig David Born To Do It, Wildstar/Atlantic
catalog number: 8573-88081-2
A 21 Performance Notes:
Two very good pop recordings that show off a systems
ability to groove. The A 21 worked its magic and made these two recordings extremely
fun to listen to by digging deep and uncovering unheard before material.
Misc.:
Stereophile Test CD2, Stereophile catalog
number: STPH 004-2
Chesky Jazz And More Audiophile Tests Volume 2,
Chesky catalog number: JD 68
Stereophile and Chesky have produced some outstanding
recordings for testing several aspects of a systems performance. Highly recommended.
Many more disks from my 1000+ CD collection were used however
the recordings listed above allowed me to focus on several sonic characteristics I've
become accustomed to; having listened to the same disks over and over again during
equipment evaluations.
When listening to a new piece of equipment I immediately try
to distinguish its ability to integrate with other components in my system. Not all
components work well with each other and there are times when the introduction of a new
piece of equipment is quite detrimental to the signal chain. Prior to installation
of the A 21, I had been using a Proceed AMP 2 and just recently a Citation 7.1 (Madrigal
Audio designed and manufactured this piece) 4 channel amplifier bridged to output 400
watts per channel into the Mirage M3-si's. The Citation produced an enormous amount
of power however overall detail and transparency were reduced and a small amount of upper
midrange distortion was apparent, especially when listening to solo piano and orchestral
strings. The Proceed AMP 2 on the other hand did a great job of driving the upper
midrange/treble end of the spectrum, however low level detail and articulation was smeared
by the reduced current capability and not quite adequate 150 watts per channel
output. The A 21 bridges the gap between output power and transparency. Not
only does the A 21 produce enormous amounts of power, it has a very refined approach to
amplification often found in super high end amplifiers. Midrange and high frequency
transparency is outstanding, especially for an amplifier in the 2K price range.
Instruments were so natural sounding, vocals so etch/sibilant free I often had a hard time
believing what I was hearing. Seriously...performance like this is usually reserved
for those fortunate enough to afford upper echelon $5,000+ 2 channel amplifiers.
John Curl is an amazing engineer...
Performance
Summary:
Low end: Deep and powerful. The A
21 controls the low efficiency (83dB) M3-si's 10" drivers with authority and should
do very well with the most demanding loudspeakers.
Midrange: Smooth, free of grain with an
ever so slight forwardness that brings male and female vocals to center stage. The
sweet, grain free midrange reminds me so much of the Mark Levinson 332 amplifier I once
owned. Keep in mind that my statement regarding grain is based on well recorded
material. Poorly recorded vocals will be exploited by the A 21's ability to present
the input signal in its purest form on the output..
High Frequency: Smooth, delicate and
detailed yet not over analytical (sterile).
Dynamics: Where do I start? The
current producing capability of the A 21's massive power supply allows the loudest
crescendos to be truly experienced without any sign of congestion or strain. This
amplifier will knock you off your seat.
Articulation/Pace: Fast walking bass
lines in Jazz music demand a lot from an amplifier. If the amplifier does not
produce enough current during a complex passage, often times each note played on the bass
becomes smeared and the listener loses note distinction. The A 21 is outstanding at
maintaining pace without loss of articulation...quite an experience which brings the
listener closer to the studio, and/or live performance.
Power/Control: Again, this amplifier is
capable of reproducing the most powerful, intense musical passages without sign of strain
or upper frequency haze. The A 21 provides more than enough power to drive the most
demanding loudspeakers.
Soundstage: The Mirage M3-si's are
known for their wide, open soundstage and require an amplifier capable of exploiting their
strength. The A 21 did not disappoint. In fact, the sound stage with the A 21
was the best I've ever heard from the Mirages.
Imaging: Scary. Placement of
instruments can easily be distinguished both on the vertical and horizontal planes.
Center imaging is so accurate it's as if I could reach out and touch the performer...now
that's an amplifier.
