Classe CT-2300 Two-Channel Amplifier Listening Tests
CD:
Anne Bisson – Blue
Mind
I
had never
heard of this singer before but it was handed to me by a close friend
that said I should check it out as a reference quality recording to
really hear a loudspeakers vocal prowess and ability to properly
place all of the instruments within the front soundstage. Track #3
“Hoping
Love Will Last”
started out with a nice piano melody along with the angelic voice of
Anne Bisson. Her voice emanated front and center tricking even the
most experienced listeners like myself into thinking the center
channel was playing. The tonal characteristics of this track
sounded similarly good on my reference Denon POA-A1HDCI amplifier and
the Classe CT-2300. Initially I wondered what all the fuss was about
the Classe. Well that wondering quickly ceased about 1 minute into
this song. Patient listeners are rewarded with deep extended bass
you frankly don’t expect from this recording. On my reference
Denon amplifier, the bass got compressed and lacked definition as the
volume level was turned up proving it just couldn’t fully handle
the 2.6 ohm dips that the Status 8T speakers exhibit in the lower
bass regions. Even the high powered A1400-8 class D amplifier I had
on hand simply didn’t provide satisfactory bass control and overall
clarity, perhaps even less so than the lower powered Denon. Only the
Classe CT-2300 and Pass Labs X350.5 amplifiers could properly drive
my speakers here. The CT-2300 produced tight deep undistorted bass
in a very similar fashion to the Pass Labs amp. Tonally we did here
a slight difference between the amps. The Pass Lab’s seemed to be
a bit more forward in the upper registers making the high frequencies
pop out at you while the Classe seemed a bit more laid back
persuading you to listen while not drawing attention to itself.
Neither myself nor the other two listeners present in this comparison
could definitively say which sounded better as we all felt they both
sounded stellar. The very fact that the Classe amp was hanging with
a much more expensive esoteric amplifier spoke volumes for how good
this amplifier was proving itself to be.
SACD: Andre Geraissati - Canto das Aquas
My
wife picked up this little gem for me at a CES show nearly 7 years
ago and until recently it
remained shelved. I was quite flabbergasted by the quality of the
recording and the content when I finally dusted it off to take a
listen. This music is classified as Brazilian Instrumental and I
really took a liking to it. Each instrument was individually mic’d
with top of the line microphones and two additional mics were used to
record room ambience. Reference level electronics and recording
equipment was used all of which was listed in the recording insert.
According to the label, this SACD was recorded at the most
sophisticated recording studio in Latin America. Based on the
pristine sound quality I was hearing, I have no reason to doubt that
claim. I chose this recording to get an understanding of the
CT-2300’s ability to finesse. Track #1 “Agreste”
demonstrated the CT-2300’s resolve at extracting all of the details
in this recording. The acoustical guitar was anchored to the left
speaker while the triangles panned the front soundstage. The noise
floor was dead silent and you could clearly hear the finger sliding
up and down the strings before they were even strummed. The reverb
from the guitars in track #2 “Frazenda”
was hypnotic. I’m pretty certain that the guitarist employed the
Lexicon Reverberator that the insert mentions for this recording on
this track. There was so much body to the recording that it sounded
like I was planted at the live studio recording. Track #8 “Entre
Duas Palavras”
opens with some nice background cords on a synthesizer with the
acoustic guitar front and center soundstage. This song seemed to
have a Pat Metheny mood to it which I was really digging. The deep
bass notes displayed excellent transients and had me almost begging
for more. I really cranked up track #9 “Benguela”
simply because it just seemed to me the CT-2300 wanted me to do it.
The nylon string g
uitars sounded pristine with no hint of edginess at
any listening level. Again this felt like a live performance to me.
SACD: Patricia Barber – Modern Cool
I’ve written about this album many times in past reviews and for good reason. It separates the men from the boys, so to speak, with home audio systems. On a system without compromise, you are showered in a holographic front soundstage and plummeted with deep extended bass that rivals even the best live amplified performances. Track #1 “Touch of Trash” doesn’t waste any time exercising the woofers in your speakers and testing your amplifiers ability to drive them. The CT-2300 was right at home perfectly controlling the speakers. Track #7 “Company” is the absolute best song on this album in my opinion. You know you’re in for a serious listening experience right from the first snare drum hit. The stand up bass simply pounds your chest while you experience the drum kit as if you’re sitting right in front of it. The trumpets extended beyond the vertical plane of the speakers and Patricia’s vocals remained anchored and crystal clear despite all of the complex instrumentation paining the soundstage.
Blu-ray:
Jienat - Mira (this is a recommend purchase)
You’re
probably wondering why I am using a muli-channel
Blu-ray as a source for reviewing a tw
o-channel amp. Remember when
I said I am running my new reference speakers fullrange with the
subwoofer/lfe channel routed to them? Well this is one helluva
torture test for a speaker system and the amplifier that powers it.
Jienat is by far the highest quality 96KHa/24 bit multi-channel
Blu-ray disc I’ve ever experienced. This disc was recorded in
Norway employing a five microphone array surrounding the panel of
singers speaking a dialect only used by 500 or so people in the
world. An additional mic for LFE info was utilized in a close-miking
configuration. There was absolutely no compression or electronic
manipulation used for this recording. This disc is a nightmare for
wimpy speakers or amplifiers. The Classe CT-2300 loved strutting its
stuff here. Track #4 “Dancehall”
surrounds you in the middle of the room with singers all around you.
The percussion was full of life and vibrancy that you rarely ever
hear in a recording. Most playback systems are incapable of
reproducing the dynamic range of this recording but the CT-2300 did a
fabulous job delivering the power necessary for the Status 8T speaker
system to accomplish this goal with pure ease. Towards the end of
the recording, the electric bass kicked in which literally blew my
friends and myself away while we were belted with sustained tactile
bass that was not only heard but rattled the core of our bones. It
wasn’t until I cranked the volume up past the point of insanity
that I heard the CT-2300 gracefully run out of gas and hit its rails.
This made me thirst for the CT-M600 monoblock version of this
amplifier which basically bridges the two channels into one massively
powerful single channel amplifier with over 2X the power of the
CT-2300. Perhaps I will have to revisit this track if I review the
CT-M600 at a later date. However, for 95% of installs the CT-2300
should be more than enough power.
See also:
gene;908202
I am trying to get Emotiva to build me a complex load impedance bank so if enough people here chew them out for not building it for me yet, it may happen
Crafting e-mail to Emo, check
gene;908202
THX is great for interoperability but their testing on amps, and especially subs is rather anemic. Our Bassaholic certification is far more stringent than their Ultra2 or Big Room spec. Their amp testing mostly deals with dynamic testing which is how a $1k receiver can easily meet their Ultra2 requirement.
Well you know their argument about receivers and burst testing, ie it tends to be more representative of a real world program material than say, ACD continuously. Since I don't use THX speakers though, the main use I had for the certification on my receiver was that it confirmed the receiver could handle speakers dipping down to 4 ohms on the front channels; at the time I got my TX-SR707, I was only running a 2.1, so that was good enough.
As far as subwoofers go, I wouldn't mind hearing a Klipsch Ultra setup in an appropriate room, but I'm quite happy with my new Bassaholic Extreme certified SVS Ultra
gene;908200
I spent many years thinking everything in audio could neatly be measured and quantified. If fact I am pretty anal retentive about this beyond just audio but I am slowly realizing that we don't always get the whole picture from text book measurements & analysis.
This is a good topic for an article that I plan on writing when I find the time.
I do the most exhaustive testing in amplifiers that I've seen compared to any publication. I've even spoken with the folks at Audio Precision and they were impressed with my methods. I am still not 100% happy however as I'd like to do more but as you pointed out, my time is limited and I am the only person on staff that does amplifier measurements for Audioholics.
Distortion audibility is a complex topic one that the folks at AP also discussed at our 2008 SOTU event in this rather boring but interesting video:
Audio Precision Amplifier Testing Methods Class — Reviews and News from Audioholics [audioholics.com]
Again sometimes text book theory doesn't always apply to real world. I found this especially true with loudspeakers and somewhat applicable to amplification.
IHO as an engineer, even subtle differences have equations behind them and there are measurements or a combination of measurements that will correlate to how an amplifier sounds. I firmly believe this. Maybe its never been done before to that extent but I think it should be. That way audiophiles and people selling snake oil ( not implying anything to you ) can be held accountable for the travesties in this industry.
Speakers are different from amps only from the perspective of room interaction espcially with respect to seating position. There are too many variables in/for a room to even think that measurements would describe accurately how a speaker sounds. I realize that even mic placement can alter the measurements of a speaker. Its far more complicated from a variables point of view than amps that for sure. If one had a thousand years, maybe one could accurately model speaker interaction with its room.
I look forward to the article. It may change my opinion on amp's sonic signatures
Steve81;908191
I agree to a certain extent. I'd contend that measurements of an amplifier *could* tell you everything you needed to know about it, but the reality is, nobody is measuring an amplifier that thoroughly. I mean, even the aforementioned power cube test is limited; yes, you can see that the amplifier delivers power into complex loads at 1kHz, but you're not seeing the distortion profile, how it performs in terms of frequency response into those loads, etc.
As a side note, that's one thing I can appreciate about THX certifications, ie they address both sides of the equation, the loudspeaker and the amplifier to ensure they work together.
Agreed which is one of the reasons power cube testing really doesn't interest me and hence why so few people even use them. I am trying to get Emotiva to build me a complex load impedance bank so if enough people here chew them out for not building it for me yet, it may happen
THX is great for interoperability but their testing on amps, and especially subs is rather anemic. Our Bassaholic certification is far more stringent than their Ultra2 or Big Room spec. Their amp testing mostly deals with dynamic testing which is how a $1k receiver can easily meet their Ultra2 requirement.
GranteedEV;908190
Um..... why exactly can't you measure a worst case test load?
It sounds to me a classic case of "The measurements are incomplete therefore the listening is more relevant"
But for electronics I'm not sure that should ever be the case given the dubious nature of the industry. The measurements should always be weighed greater. If that means measuring into a 1 ohm load @ 75 degree phase angle for a $5000 amp @ 10hz to 22khz, I don't see why not. It's pretty insane but the measurements should always represent a worst case scenario not a middle of the road scenario.
Likewise with loudspeaker measurements. Why only measure 30 degrees off axis when the sound at 60 or 70 or even 150 degrees off axis has been shown to affect perception?
I understand as a reviewer time constraints etc come into the picture but it's unfair to do half-measurements - and then claim that they don't help identify what you heard.
I'm not criticizing your measurements here Gene. They're great and appreciated as are the subjective commentary. But It's a bit disheartening to see you post the measurements and then claim they're inadequate relative to your experience. If your own speakers are a more complex load than the test signal, then as pretty much the publication leader we expect you to address that objectively rather than use the limitations of the measurements as evidence. I don't really like the idea that something that can be heard but can't be measured. That's awful close to "cable" territory to me. It can either be measured or you choose not to/lack the capability to measure it.
Sorry to rant especially since this was a really good review but your comment that you can hear things that you can't measure just doesn't sit well with me. I'll admit my measurement capability compared to yours is infinitesmal but I also don't make such claims. I know you know this but it feels you just word things in a certain way that gives teh wrong impression.
It seems like a very good topic for an AH article - what aspects of amplifiers when isolated - are actually audible in an ABX / single blind test? I have no doubt that if you can hear it, you can measure it but complexity is the keyword.
I spent many years thinking everything in audio could neatly be measured and quantified. If fact I am pretty anal retentive about this beyond just audio but I am slowly realizing that we don't always get the whole picture from text book measurements & analysis.
This is a good topic for an article that I plan on writing when I find the time.
I do the most exhaustive testing in amplifiers that I've seen compared to any publication. I've even spoken with the folks at Audio Precision and they were impressed with my methods. I am still not 100% happy however as I'd like to do more but as you pointed out, my time is limited and I am the only person on staff that does amplifier measurements for Audioholics.
Distortion audibility is a complex topic one that the folks at AP also discussed at our 2008 SOTU event in this rather boring but interesting video:
Audio Precision Amplifier Testing Methods Class — Reviews and News from Audioholics [audioholics.com]
Again sometimes text book theory doesn't always apply to real world. I found this especially true with loudspeakers and somewhat applicable to amplification.
panteragstk;908197
That would answer the question I posted above. I don't think I've ever seen someone measure an amp in that way in any review ever. I don't think most could handle that.
Of course not. But I don't think most could handle Gene's speakers either.
Likewise, what if my speakers were some perfect 95db/w/m, 8 ohm +/- 2 ohm where theta is +/- 30 degree. if there are multiple drivers they are each driven by their own amplifier not in parallel. ...then I don't hear the difference gene heard. What do you draw from that?
I'm just trying to figure it out. It feels to me that the real world scenario should never be a worse one than the testing scenario. And a resistive 4 ohm load is likely an easier one than a 2 ohm, 50 degree phase angle scenario like whatever Gene mentioned in the review. There should definitely be a double standard. Obviously if an amp is struggling with the basic scenario then the tough scenario is out of the question - for both measurement and ALSO listening. But for a $5000 like this Classe, it's pretty much ::expected:: to drive ultimate speakers IE Apogee or the status acoustics.