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alternate audio

CA35 ampilfier

as reviewed by Larry Cox, Francisco Duran, and Sherman Hong

Photo of CA35 Front Panel





ProAc Response 3.5.

Accuphase DP-550 amplifier.

Accuphase DP-55 CD player

Acrotec 6N-2030 and 6N-2050 interconnects, 8N-1080 speaker cables, and LAT power cords.


one.jpg (6551 bytes)Do not be fooled by the diminutive size (18x24x5 inches) and weight (25pounds) of the Alternate Audio CA-35 amplifier. This amplifier was a real discovery for me, as I had never previously heard of Alternate Audio. My reference amplifier is an Accuphase P-550, rated at 270watts (retail $9K), in contrast to the CA-35’s 25 single-ended class A watts (retail $2.5K). One would think this would be a battle between David and Goliath. The Accuphase has its advantages—better bass, effortless dynamics, and so on. However, the CA-35 possessed a special magic of its own. Choosing between these two amplifiers was more difficult than anticipated.CA35 Back Panel

As comparison began, both amplifiers sat on Black Diamond Racing cones and "The Shelf’ platforms, connected with Acrotec 6N-2050 interconnects, Acrotec 8N-1080 speaker wires, and LAT power cords. Directly driving both amplifiers was an Accuphase DP-75 CD player, with the amplifiers driving ProAc Response 3.5 speakers. The faceplate of the CA-35 supports an on/off and a standby/play switch. The back panel accommodates one set of RCA input and binding posts, a master power switch, and a detachable power cord connector. The chassis is composed of machined aluminum panels, ala Jeff Rowland. The CA-35 does have one quirk—the polarity is inverted. It is therefore imperative to reverse speaker connections. This is not sufficiently emphasized in the instruction manual, which needs to be better written. The instructions were not detailed enough to make life easy on the user.

The CA-35 had enough warmth to communicate emotion without inundating the typical solid-state-like presentation. The spatial perspective was immediate, without sounding forward. The ambiance of individual recordings came through with ease. The images of instruments were three dimensional and true, although slightly miniaturized. The music originated behind and beyond the plane between the speakers. While soundstage width and depth were not as prodigious as the Accuphase’s, it was excellent by any standard.

As one would expect from such a low-powered amplifier, the bass was not as abundant as my reference.  The quantity of bass, however, was more than made up for in quality. The bottom octave struck with speed, control, precision, and proportional weight!  The synthesizer on "Watermark" by Enya pounded, with dimensionality and proportionate authority. The intricate nuances on "Orinoco Flow" were reproduced with detail and clarity.   All instruments came through with a sense of air and space between performers that was on a par with my reference. At normal listening levels, the music never compressed or smeared during strenuous passages. The bass, drums, and twelve-string guitars on Nicky Skopelitis’ Ekstasis performed unrestrainedly, with such smashing dynamics that one forgets that the amplifier only has 25 watts of power. Nevertheless, the Alternate Audio amplifier lacked the ultimate solidity and bottom-end punch of the Accuphase.

The midrange really glowed through with the CA-35. Vocals and saxophones were accurate and natural. There was a sense of "tactility" that is rare among mid-price amplifiers. Dusty Springfield’s voice on Casino Royal came through smooth and lifelike, reminiscent the sound of tube amplifiers. Low-level resolution was effortless. The piano notes in Beethoven’s Pathetique, on the soundtrack Immortal Beloved decayed naturally, and were suspended in air. However, the CA-35’s midrange was still not quite as transparent or palpable as that of my reference.

Higher frequencies were also exceptional. The treble was transparent and clear, though slightly polite and warm. As a result, music sounded smooth and gentle. Guitar strings were pleasant and yet detailed on "Nobody knows when your down and out" on Eric Clapton Unplugged. The cymbals were brushed with authentic sweet metallic-ness on Oxnard Session Volume One.

The top end sounded slightly rolled off in contrast to my reference. The Accuphase possesses the ultimate in extension and resolution without sounding excessively warm, bright, or etched.

On disc after disc I found the tube-like liquid quality of this amplifier quite delightful. I listened to entire CDs, as opposed to just individual tracks. The tonal balance of CA-35 was somewhere between tube and solid-state amplifiers. Top-to-bottom coherency and leading edge transient response were impressive indeed. The Alternate Audio will compress if pushed hard. Moderate listening levels or efficient speaker designs will be necessary to get the best out of this amplifier. Overall, I can’t recommend this amplifier more enthusiastically! It’s wonderful that a bit of sonic paradise can be attained without taking a second mortgage on the house. I can’t wait until its bigger brother appears on the scene.  Sherman Hong





Spendor SP 7/1.

Audible Illusions Modulus 2D preamplifier. Classe CA100 amplifier.

CAL Icon MkII CD player.
Oracle Delphi MkII turntable, AudioQuest PT7 tone arm, AudioQuest 404i cartridge.

AudioQuest Emerald 3x interconnect and Midnight 3x speaker cables.

API Power Pack.


two.jpg (6646 bytes)My listening tastes are still evolving. When I purchased Vandersteen2Ci’s, I wanted a full-bodied sound which conveyed a sense of lyricism and melody, knowing that the speaker was not as detailed as many others. I still like and respect Vandersteens, but after years of listening to more and more gear I don't think that I could now accept their compromises. (I haven't heard the newer 2Ce's, so have no comments about them.) What I want at present is gear that remains lyrical and melodic, and with plenty of detail, but not at the cost of accurate timbre. I want warm but detailed sound. Previously I equated warmth with bass extension, but that is a mistake. There are lots of components with deep bass, but which lack the warmth that seems accurate to me. Thus, the lamb I sacrifice for contentedness is bass extension. The interim holy grail is a resolving system with realistic timbre and a slightly warm, perhaps even dark sound. I'm not sure that I really want darkness, but I know that a bright system would be short-lived in my living room.

When I moved from a PSE Studio Mk IV amp to the Classe CA 100, I got just about as much detail but a bit more tube-like warmth, while retaining the sense of "properly" reproduced timbre. I have been quite happy with the Classe. What has surprised me these past several weeks is that I now hear how grainy it is, when compared to the Alternate Audio CA-35 amplifier. The Alternate is a further step along the road to more refined, more detailed sound, while retaining the ability to reproduce realistic timbre.

The CA-35 is much more refined than the Classe, and at $1k more in cost, perhaps it should be. What I mean by refined is that there is a lot less grain at every frequency response. The treble is clearer, without being harsh or etched. What is fairly astonishing to me is the difference between the Alternate and the Classe in the midrange. On Israel Kamakawiwo'ole's Facing Future, the late singer's angelic—but not pantywaist—voice is communicated with a greater sense of clarity than with the Classe, as are his ukelele and the steel guitar. On track 10, the latter instrument is played very low, and to hear it with less grain and a greater sense of strings vibrating in air is a real achievement, at least to my ears. That ability is part of what makes this amplifier pretty spectacular. 

Almost everything is more transparent and more "here" than with the Classe. That increased transparency makes the singer more "present" in the room, though not as palpable or full-bodied as some tube amplifiers.

In combination with my tube preamplifier, the Alternate amplifier gives an excellent sense of presence, perhaps as much as most people would want. Many people describe Classe amplifiers as "tubey." While it has the excellent character of palpability commonly ascribed to tube amplifiers, the Alternate also bears comparison to tubes in its liquid reproduction of sound. Like tube amps, the Alternate doesn't go really deep. However, like solid state amps, the bottom end it does reproduce is quite solid and very tight. Its frequency response is seamless. In comparison, the Classe's more robust bottom end sounds as though it might be a bit overstated, although I confess that I really like it. The Classe's bottom end invites playing more dance music, more rambunctious rock and roll, or anything that has a substantial bottom end. I found that the bass playing of Charlie Haden on the Missouri Sky CD to be a bit more restrained and less full-bodied on the Alternate Audio amplifier, though not disappointingly so.

Tone seems to waver a little less than with the Classe. In particular, Carlos Santana's licks on John Lee Hooker's album seem more realistic. In my system, this translates as not requiring the volume to be higher to get a full sense of the micro dynamics of the instrument. Lower volume levels are not mandated because the sound is harsh, but rather because the quieter transients on the guitar seem to be more clearly or "correctly" reproduced. Perhaps like the portions of nouvelle cuisine, you don't need as much to get the full flavor of what you are consuming. The Alternate almost always conveys a greater sense of transient speed and rightness than the Classe. Additionally, the top end is smoother than the Classe’s, even though it is more extended and perhaps a bit more forward, without being bright.

Some classical music fares better on the Alternate amplifier, as the greater numbers of instruments are more clearly delineated. While resolving more, the amplifier doesn't lose the sense of timbre that is so important to me. Large scale works like Holst's Planets are a little more inviting on the Classe, but Vladimir Horowitz' rendition of Beethoven's Pathetique is more emotionally engaging on the Alternate because it is more delicately conveyed. What doesn't sound surprising to me now, but would have seemed heretical before living with the Alternate, is that the amplifier resolves better in the near field. Its rendering of small-scale, intimate music seems to call for the listener to be seated more closely to the speakers.

The Alternate Audio CA-35 could be the right amplifier for you if you are in a small listening room, listen to small jazz combinations or string quartets, or just prefer to listen at low volume levels. In that environment, the Alternate kicks the Classe's behind. Moreover, if immediacy is important to you, this amplifier will bring you within hand-shaking distance of the performers. However, if you want a funkier amplifier that will move more air for dance music or large-scale orchestral pieces, this amplifier might still do it for you, but you may have to surrender the driving sensation other similarly-priced amplifiers can provide. The CA-35 is certainly worth an audition. For this reviewer, at this time, I want the macrodynamics and the more substantial bottom end of my Classe. While a truncated bottom end is not a problem, the Alternate doesn't have quite enough warmth to make me switch. The Classe isn't as highly resolving as the Alternate–it is grainy by comparison. If there were a smidge more warmth in the Alternate, I'd push the Classe out into the classified ad section without hesitation.
Larry Cox





ProAc Response 2s.

Classe CP60 preamplifier. Classe CA200 amplifier.

Pioneer DP 54 as a transport.

Acrotec 2050 interconnects, 1050 speaker cables, and digital cable.


three.jpg (8484 bytes)When I first listened to the Alternate Audio CA 35 amplifier in my system, I thought to myself, what's the big deal? The tonal balance, bass, and soundstaging capabilities were OK. It had a warm, sweet sound, but not much ambience. After a call from fellow audioMUSINGS reviewer Sherman Hong, I was informed that I had to reverse the polarity at either the amp or speakers. After doing so, the sound really snapped into place. But before we get too far into the sound of this amplifier, let's check out some of its features.

The CA 35 is a stereo, high-bias, class A power amplifier which puts out 25 single-ended watts per channel. There are only two Mosfet transistors in the signal path. A stanby circuit keeps the amp warm without excessive power consumption. There is full monitoring of DC offset and temperature conditions, indicated by LEDs on the front panel. By the way the CA 35 does run very hot!

The CA 35 is your basic black, low-profile, rectangular amplifier with heatsinks on the sides. The most striking features of the amplifier's back side are the beautiful five-way binding posts made by TIF. The inputs are standard unbalanced RCAs. Also on the back is the main power switch, alongside the left and right channel fuses and the IEC detachable power cord.

I threw an eclectic set of discs at the little guy, and for the most part it came through in good shape. With the amplifier in my system, I no longer cringed at cymbal crashes, snare drums, or dynamic peaks of any kind. The Eagle's Hell Freezes Over was gorgeous. The music sounded smooth, with an overall golden sheen. Even the clapping of the audience sounded natural. The depth of the hall was also very apparent.

Then I put on a disc which is not bright, sharp or steely in sound, but the music sure is, Metallica's And Justice For All. I came across this baby through my guitar slingin' nephew, because I told him I liked the song, "One." This song is a musical version of a film called Johnny Got His, which deals with a guy who comes back from the war with no appendages and deaf, dumb, and blind. He communicates by using his head to tap out Morse code messages. Very powerful, and transferred well to music by Metallica. For the most part, this disc is straight-ahead, gut wrenching, loud, hard rock. I feel this disc should be run through a stereo system now and then instead of the usual whimpy audiophile test disc, and played real loud, just to see if your speakers can still hang. Mine sure did.

How did it sound? The guitars rang out as clear and sweet as I've ever heard electric guitars through my system. Guitars, drums, and James Hatfield's gravelly vocals, all came together very coherently. Metallica? Sweet? Coherent? Am I losing it? OK, let's turn to the Mortal Kombat soundtrack album. About this time, my wife started yelling from the kitchen to turn that racket down. What does she know, she likes Yanni. With the MK disc, same deal tight, clean, and slightly warm. If anything, I had a problem with dynamics on these discs, but more on that later.

So I thought, what the heck, let's switch gears, and put on the Anonymous 4 Yools Night disc. As the Dice Man would put it, "You know, the CD of four chicks in a church singing their hearts out." I wasn't really in the mood for this kind of music, but I wanted to throw everything at the little CA 35. Once again, the vocals were very natural sounding, and sibilance was very well controlled. I did notice that when all four women hit the louder passages, a slight excess of energy came through, but since I hear this on my Classe amplifier as well, it must be in the recording. It also seemed that I had to turn up the volume quite high on this disc to get a better sense of the recording space, but I still think this is due to the way the CD is recorded. However, after a few moments of listening I pretty much forgot about being critical, and just enjoyed the singing. Music to soothe the savage beast.

One thing leads to another, so on went Corelli - Concerti Grossi Opus 6, with Nicholas McGegan conducting the Philharmonia Baroque Orchestra on Harmonia Mundi France. The music just seemed to blossom from the instruments. This to me this is the strong point of this CA 35. String sounds of all kinds, whether strummed, plucked, or struck with a bow, from the lower midrange to the lower treble, sound ever so sweet and coherent. Vocals sound real, and there is a layering depth to the soundstage that is uncanny.

But alas, in life there always seems to be something out there to spoil the party, and in this case it was dynamics. I first noticed this on the Eagles disc. The guitars opening track 6, "Hotel California", sounded great, but as soon as the bass and drums kicked in, things seemed to wimp out. It sounded like Don Henley was holding back every time he hit the drums because he didn't want to disturb anyone. There didn't seem to be as much impact on the drums as I'm used to hearing through my Classe amp. Also, the bass guitar had plenty of body, but not as much impact or snap. The pace and rhythm sounded slightly lazy and lackluster, as if the Eagles were tired. The same was true of the Mortal Kombat soundtrack. The bass reached down pretty far, but it just didn't have that gut-wrenching, chest-hitting slam. The pace seemed a bit slow and lacking in immediacy and life with the Corelli disc, also.

If it sounds like I'm picking on the little CA 35, perhaps a comparison with my Classe CA 200 amplifier is in order. Both amplifiers are in the same price bracket. With the Classe amplifier back in the system, the Eagle disc sounded faster and slightly leaner. It still sounded smooth, but not as rich and warm as with the Alternate Audio. Vocals were more open-sounding and more effortless, if a touch lighter. On the Anonymous 4 disc, even though the vocals didn't sound as golden or sweet through the Classe, they were still very good. I could also hear the vocalists drawing breath at the end of a phrases more easily. More resolution, perhaps? Cymbals and high hat sounded sharper and gutsier and more prominent. When electric guitars were being picked on the Eagles or Metallica discs, they sounded sharper, and not as rounded and sweet as with the Alternate Audio amplifier, with a very slight distortion and grunge noticeable. The sound smoothed out quite a bit when I switched the Classe to balanced mode, the background became more silent, and the noise floor dropped. As far as reproducing the sound of electric guitars, the Classe sounded more real, if not as sweet as the Alternate Audio.

The CA 35 is no slouch in the bass department, but it couldn't in this area with my Classe CA 200. This is where system matching might come into play. In talking with one of my fellow audioMusings cohorts after we had both finished our reviews of the amplifier, I discovered he totally disagreed with me about the bass performance of the CA 35 . In his system, which includes a pair of ProAc Response 3.5s, he found the bass fast, dynamic, and clean. He also had the Alternate Audio preamplifier in his system, which makes me think that maybe my Classe CP 60 preamplifier is a mismatch with the CA 35.

I really enjoyed listening to music through the CA 35. The seductive sweetness and warmth of this amp kept overcoming my critical listening and letting the music flow through me. If you're interested in a single-ended solid state design, take the Alternate Audio CA 35 for a spin and see what you find.
Francisco Duran

Alternate Audio CA35 amplifier
Retail $2500

Alternate Audio L. C.
TEL: 801 - 434 - 7226