[-Richard-]

Review of Carver Professional ZR 1600

I was lucky as an adolescent to have been exposed to classical music and high end audio by an uncle who was an opera aficionado, and a neighbor who was studying to be an orchestra conductor. I used to hang around what passed for audio shops at the time when I was eleven and twelve, “critically” listening to various speakers and components. My father, who also loved music as much as I did, gave me the supreme gift when I turned 13 of a “high end” audio system: Warfdale coaxial speakers in a sand filled cabinet, driven by a tube receiver and turntable. My father worked as a “cutter,” in a dress factory, often 7 days a week to make ends meet for his family, so this was quite a major expense for him.

Ten years ago I returned from teaching in India and decided to put together an audio system based on what was the state of the art in current technology within my limited budget. I read every magazine I could and it did not take me long to realize that there was a dizzying array of products with competing design topologies.

My wife, Deborah, who is as passionate about music as I am, and whose hearing acuity is far more sensitive than mine, accompanied me on forays to audio shops to listen to speakers and various components. After listening to at least 30 different speakers (over a period of a year), all highly regarded by the audio press, Deborah expressed an affinity for the Ruark Crusader 2’s, a pair of relatively small floorstanding British speakers. It was the Ruark’s “natural” warmth with the voice that beguiled her...Deb listens to a lot of female jazz singers.

Two years ago I also purchased a pair of Maggie 1.6qr’s, which I modified based on Ed Hsu’s recommendations (a beefy copper inductor, and huge Hovland capacitors set up in series). To drive both pairs of speakers, I was using an older (over 20 years old) SS Mitsubishi receiver, known for its excellent FM reception. I also purchased a small 8 watt tube SEP(entoid) amplifier from Wright Audio ($750. with built in passive preamp and tone controls) and experimented with various tube combinations. For media, I turned to CD’s and purchased a CAL Icon MK 2. During the last ten years I did many in-home auditions of various amps (and speakers and CD players) and I continued to visit audio shops wherever I traveled.

I have written this brief (for me) overview of my audio “history” in order to give the reader a sense of my background as an audio hobbyist.

Several months ago my old Mitsubishi died (thank god) and that gave me the final excuse to purchase a new amp. I narrowed the field of tube and SS amps (and hybrids) within my highly restricted price range. I also pursued vigorous research into the new technology of (so-called) “digital” amps.

I found Jesse’s (aka JCC in AudioAsylum) review of the Carver Professional Zr series of “digital” amps on Audiogon and was highly intrigued. I also read Matt’s review (aka mttbsh) in Audio Asylum. Jesse put me in touch with Dan (aka DrD in AA) who further “fleshed out” the characteristics of the ZR series of amps. I quickly became aware that DrD was extraordinarily knowledgeable about all things audio. More importantly, DrD understood the interconnectedness of how various components of an audio system interact with each other.

Everything Jesse, Matt and Dan said about the Zr series of amps convinced me that my search was over. I plunged ahead and purchased a ZR 1600 (300 watts per side into 8 ohms) for less than $800. I wanted to give my Maggies as much “power” as they could take to allow them to come “alive.”

The burn-in period of the ZR 1600 was considerable. I used the “built-in” preamp at first to drive the amp. The sound was promising but somewhat hard and thin. Matt was using a passive NHT preamp. I researched Audiogon and Audio Asylum and found a sensitive and intelligent review of the tiny Axiom passive preamp which I subsequently purchased for $150. Dan told me to be patient until the Axiom arrived and he was right.

I bypassed the “built-in” preamp of the ZR 1600 and hooked in the tiny Axiom and immediately the amp smoothed out, the dynamic range increased remarkably, and the frequency extremes stretched out in both directions. Voices came “alive” with a warmth and “naturalness” that reminded me of the best tube amps I have ever heard. But the best was yet to come.

Dan made me “review” my entire system with him, and he became convinced that my cables and interconnects were not allowing the ZR 1600 to really bloom properly. He suggested a very inexpensive cable company, Signal Cable run by Frank. I purchased 2 power cords, an interconnect and a pair of speaker cables from him. I hooked them up to my system and began to burn them in, (along with the ZR 1600 which was not, and is still not fully burned in).

One morning, after about 9 days of burn-in on the new cables, I  cued up a disk on my CD player, Cassandra Wilson’s Blue Night 'til Dawn. As the music flowed out of my Maggies, my wife Deb and I were astounded. A entirely “holographic” (Dan’s apt phrase) musical event came pouring out...details I had not even imagined to be on this disk were suddenly and “naturally” present, as if they had been there all along, a powerful articulate bass emerged, and Cassandra’s voice floated in the room, alive, throbbing with warmth and emotion. Dan was right...my old cables were not allowing the ZR 1600 to bloom, but Frank’s (rather inexpensive) cables certainly changed all that.

Yes...the Maggies certainly came alive...in a way I had not even dreamed was possible....but it was when I finally hooked up the Ruark’s to the ZR 1600 that my jaw dropped to the floor.

The Crusader 2, Ruark’s are very British speakers. Wonderful with voice, but somewhat laid back and not terribly exciting...which was what Deb and I liked about them...they were not at all fatiguing and we could listen to music through them for hours, without these speakers ever calling attention to themselves. Still, I had always found the Ruark’s less involving than my Maggies...I thought they tended to “flatten” the music somewhat and hold onto the notes a bit to long (after the Maggies, most box speakers lose some of their musical charm). Suddenly the Ruark’s came alive...I mean the music burst forth with a tremendous exhilaration of dynamic pulsating sound...dimensional, deep, present, transparent, liquid and warm...instruments separated themselves out from one another...each instrument sounding their distinctive timbre. Their was a new “space” around each instrument that was palpable. Both Deb and I were truly astounded. The ZR 1600 transformed my $3000. Ruark’s to sounding like $15,000. state of the art speakers.

Any caveats? Yes, I have 3. For one thing,there is a narrow region in the mid to upper treble that is a bit hard on certain musical material that I have not been able to resolve. I am not certain what in my system is to blame for it and (as I have already said) it is only present on certain CD material and I can easily live with it. It could be my room which may have to be more judiciously damped to absorb the first reflected sound waves (which I will probably never do). It could be the plugs I am using to fit my RCA terminated interconnects into the Neutrik inputs of the ZR 1600 (Jesse has pointed out that I would be better off going straight into the Neutrik inputs with my interconnects). The other caveat is that the speaker cable binding posts really only accept banana plugs (before I purchased my new speaker cables from Frank, I had to jam one prong of my previous cables into the “hole.”). And last, their user manuel is skimpy. It is not easy to negotiate your way around the highly condensed information in the ZR 1600 manual, unless you have had a great deal of “professional” experience (which I do not have).

However the ZR 1600 has a great deal of flexibility (being actually designed as a “professional”  amp used by musicians in concert). For one thing you can alter the Internal Jumper Settings to accomodate the “strength” of the incoming signal (CD, vinyl, or FM for example) and the efficiency of the preamp you are using. There is a great deal more you can do, but right now it is beyond my knowledge and experience to know how to (or even if I need to) take advantage of these various configurations.

I would like to paint, with a rather broad brush, my previous experience with a wide variety of different high-end amplifiers. Almost all of the SS amps I have heard all sound a “bit” flat, a “bit” forced, a “bit” hard and somewhat dry, although usually quite extended in frequency range (yes...there are SS amps that create a plumper sound like tubes). The majority of powerful tube amps I have heard tended to sound somewhat soft and overly smooth, not particularly transparent, depleting some of the dynamic character of the music. Hybrid amps do combine both attributes of the SS and tube amps, but I still heard a smoothing out of the musical information as a “characteristic” of their “presentation.” Small SET amps are wonderful for their dimensional “presence,” sense of space, and intimacy, allowing the human “warmth” of voices (and some instruments) to come alive, but they tend to lack dynamic range.

The ZR 1600 has its own musical signature as well. It is involving, holographic, detailed, rich, dynamic, and revealing. It has some of the attributes of an SET amp in its ability to sound intimate...although it is incredibly powerful. I am still asking myself if this amp has that elusive characteristic of “continuousness” that Harry Pearson (Absolute Sound) talks about as being an essential attribute of “experiencing” the “liveness,” the flow, of a “real” musical experience. Yes...I think that it does.

I have never heard an amp sound as good in any audition I have ever heard in an audio shop or at home.

Let me point out that the ZR series is not a “true” digital amp. It is really a mosfet amp that uses the Tripath chipset to “force the mosfets to perform at their optimal efficiency at all times” (David Garlett of Carver Professional). This is a very important direction of amplifier design to become aware of. There is no reason why a digital chipset could not be used (in the future) for example, to force tubes to perform at their optimal efficiency (this may be what David Berning is doing with his newest amps). Amplifier design seemed to have reached something of an impasse, just before the emergence of the new digital technology. Yes of course, amplifier designers are incredibly creative, and will always find new ways of “perfecting” the older paradigms of amplifier design, both tube and SS. But controlling transistors (or possibly tubes) with digital chips will completely reshape our experience of audio in the near future. And then there is the “direct” bit stream of the digital signal from source to amp to speaker that is also in the works. Dan has suggested that speakers in the future will have their own “digital” amps built into them that would be optimized for that particular speaker...a perfect “match” so-to-speak.

I would also like to touch on the idea of sound shaping. It has become synonymous with the “high end” over the last several years to develop a “purist” philosophy of not “damaging” the signal with “colorations” that seem to insert themselves in tone controls (for example). I for one, would not mind if I had a far greater control of the musical signal from a preamp that had built into it a signal wave controlling (shaping) device, like those used in the Z system, or Tact audio preamps, but far more user friendly and accessible...here again the digital “direction” holds promise to create these devices cheaply.

I hope I do not offend anyone's “purist” sensibilities by suggesting that our computers, may in the near future, be the “controlling” devices for our audio systems...already the iPod is making history as a source for digital musical information. According to John Atkinson (Stereophile), “...the iPods measured behavior is better than many CD players...” (pertaining to jitter control) and Wes Phillips, “...completely indistinguishable from the original CD...” (using the high rez AIFF format). The Absolute Sound spotlighted the Kivor Digital-Audio Server, at a cost (hold onto your seat) of $16,000 to $20,000, which the iPod does for $400., without (of course) ever mentioning the ipod in the article(?). Clearly there is a “digital” revolution going on...and on the “cheap.”

And I would like to finish this “review” on the note of “cheap.”  The ZR 1600 is “cheap” by any “high end” standard. That is a good thing. Speakers have become frightfully expensive over the past 15 years or so. The ZR 1600 and a very “cheap” passive preamp, like the Axiom, can allow the music lover to place more of their hard earned cash into the speakers they love and desire...in order to obtain the sound that brings to life the music we all need to replenish our souls thirst for the ineffable...something music, of all of the arts comes closest to.

I say bravo to Carver Professional for leading the way in providing digital amplifiers at a modest cost. So that lovers of music, like my wife Deb and myself, who are always on a very limited budget, can enjoy musical nirvana on a shoe string.

If any changes occur in the sound of my system I shall keep everyone informed.

[sica]

Very nice review, very detailed, intelligent and sensitive.  I like your consideration of system synergy.

[-Richard-]

I am new to this illustrious forum.  I did not read all the threads pertaining to the ZR series of amps before publishing my "review."

In any case, DrD and Dan (as mentioned in my "review') are none other than DMason. I mention this out of respect and deep appreciation for his incredable help and encouragement in all things audio.

-Richard-

[MttBsh]

I too would like to express my appreciation of DrD for his unique insights into all things audio, and his willingness to guide us newbies to  unprecedented value (If you want to know where audio - and value in audio - is headed, read his posts) On top of that, he's a heck of a nice guy... thanks Dan!

[KKM]

Richard, thanks for your informative review and insight, I too have a pair of Maggie and would like to hear how your system sounds as time passes.

[Rob Babcock]

Your insightful and thorough review is most welcome here, Richard.  I'm planning on trying the 'Z' myself (had a couple unexpected expenses lately , or I'd have already sprung...).

I'm curious, do you actually prefer the Ruarks to the Maggies?  Without hearing the pair, it would seem that the Maggies and the Carver may have complementary strengths that may mitigate their potential weaknesses.  Do you find the match to be synergistic?  I gather that you do to a degree, but I guess I'm asking, are your Ruarks more so?

Great review!  And welcome to AC!

[-Richard-]

Hi Sica,

thank you for your nice thoughts.

-Richard-

[-Richard-]

Hi KKM,

Yes...of course...I feel I have a lot of work ahead of me to try and work with my Maggies to see how far I can go with getting the best from them.

I am particularly interested in working with the issue of transparancy.

At their best, (as you undoubtedly know from you own experience) the Maggies allow the music and voices to float with the "air" of the room (seemingly completley free from its source). This creates a papable presence that seems to combine the best attributes of electrostatic speakers and dynamic speakers. However the dynamic power of the Maggies far exceed any electrostatic I have heard...especially with the ZR 1600 driving them. If I can get the Maggies to reveal a bit more transparancy, I think the musical experience would be even more pleasurable.

-Richard-

[-Richard-]

Hi Rob,

Thank you for your warm greeting and nice thoughts.

Yes...alas...the "Z" preamp is one of those components I do not think I shall ever be able to afford...but it is so intelligently conceived and beautifully designed that I can not help thinking that it would solve many, if not all of the issues I currently have with my system.

Robert Green (the Absolute Sound) calls the "Z," "tone controls without tears." And I believe you can do some amount of room correction with it as well. Lovely!

I would love to hear your experiences with it, when you are able to see your way clear to getting one.

Perhaps I am one of those audio hobbyists that would never really be fully satisfied with any one speaker. My dream would be to have several speakers of different designs to play with alternatively. And that is what I do with the Maggies and the Ruark's. I go back and forth, giving each a few days to play, what is essentially, the same musical material.

Strangely, Deb (my wife) finds this very satisfying as well. We both look forward to switching speakers and it is always a revelation.

I was actually considering selling the Ruark's before I purchased the ZR 1600. But once the amp (and new cables) began to "burn in" I was astounded at how good the Ruark's sounded. Admittedly Deb kept telling me that I had never really given the Ruark's a chance, because my amplification was never of a high enough quality...and it turned out that she was right! However even Deb was not prepared for the effect the ZR 1600 had on the Ruark's.

Many reviewers who have listened carefully over many years to dynamic speakers claim to be able to hear the cross over points of most of them. Some of these same reviewers mention that the Maggies have a coherency that is unique to them. With the SS amp I was previously using, I think I could hear the crossover points of my 3 way Ruark's on some musical material. The ZR 1600 changed that completely. I no longer hear any sense of "seperation" of the musical experience...only music, whole and complete is perceivable now.

As for the Maggies, a new depth of space in which the instruments and voices reside has been fleshed out by the ZR1600. Before I used this amp the Maggies always seemed a bit on the thin side of "natural." The ZR 1600 allows the music to penitrate the space of my room with a fully realized musical "illusion."

The Ruark's have tremendous presence in the lower midrange down to perhaps 38Hz. And being a dynamic speaker, it builds a powerful foundation under the music. The Maggies (which go to 40Hz and some owners claim they go even lower when optimised) cannot build that kind of foundation being a planar speaker..but it does create the neccessary "illusion" of the bass, so that when they are playing, you never feel the lack of it. Still, certain musical material naturally sounds more impressive on each speaker, because of what each speaker does uniquely.

I am afraid I am not quite answering your question, Rob. But the ZR 1600 does seem to bring out the best of both speakers and I Iove listening to music through each of them.

You are quite right when you suggest that the Maggies and the ZR 1600 may "have complementary strengths that may mitigate their potential weaknesses..." In the sense that every audio component has strengths and weaknesses, and it is here that we audio hobbyists must find the correct synergy in matching components to make the whole thing work.

In this sense a "review" of any component is always "conditional."

Thanks again for your kind thoughts. It is really a pleasure to be in this forum, and share ideas with all of you.

-Richard-

[_scotty_]

Hi KKM,

Yes...of course...I feel I have a lot of work ahead of me to try and work with my Maggies to see how far I can go with getting the best from them.

I am particularly interested in working with the issue of transparancy.

At their best, (as you undoubtedly know from you own experience) the Maggies allow the music and voices to float with the "air" of the room (seemingly completley free from its source). This creates a papable presence that seems to combine the best attributes of electrostatic  ...

 Everything now sounds more real doesn't it. I think this product and some others may come closer to "the absolute sound" standard, REAL
LIFE, which has long been ignored by designers. Kind of neat isn't it.

[-Richard-]

Hi Scotty

Yes...you quite right about the sense of "realism" that the Zr 1600, and apparently your Stan Warren designed digital amp, are capable of creating. That is the where, I think, the "revolution" in such designs actually resides.

I have never had the oppurtunity of hearing your amp but I imagine that it is a fairly unique (hand made) example of the current "state of the art" in tri-path technology. Does it use mosfets, like the ZR 1600? And did your speakers take on a new life after you began to use your Stan Warren amp with them?

Thanks for your feedback.

-Richard-

[_scotty_]

Hi Richard, The amp is not state of the art by any means. It is at least 1year obsolete.The amp is based on the Tripath EVAL board EB-TA0103.This module has been replaced by the EB-TA3020. Stan didn't second guess Tripaths design.  He optimised it's grounding scheme and gave it as low an impedence power supply at RF frequencies as was practically possible. If a company just follows Tripaths recommendations for successfully implementing their technology a fine sounding product will result. The amp is Tripaths own implemention of their technology with the fastest MOSFETS available at the  power level the amp is designed for.  The larger the MOSFET the higher the gate capacitance becomes and you need higher amperage and voltage rated MOSFETS to make higher power. A higher powered digital amp has the potential to not be able to switch as fast as a lower powered amp. Thats why Stan chose this board to turn into an amplifier instead of a higher power rated board. My amp will do 108watts/ch 8ohms and 220watts/ch 4ohms. More than enough for my 96db efficient TETON GS speakers. The amp runs in fast company but there should be a better sounding digital amp out there. Especially one with no crossover notch distortion. The amp would have the liquidity of the best state of the art MOSFET based analogue amps with the astonishing bass and quality of transparency that the best  digital amps have. This amp is coming but we haven't seen it yet. In answer to your last question the entire system came to LIFE. I called Stan and said "IT'S ALIVE" followed by the sound of manical laughter ala Dr. Frankenstein.  
   Where did your purchase your Signal Cables and is there a website
or phone number for the company.

[Cens]

Scotty,

Try this website -- I think it is what you're looking for.

http://signalcable.com/index.htmlhttp://

Regards,

Chris

[-Richard-]

Hi Scotty,

Thanks for your highly considered and nicely detailed explaination.

Here is the web sight for the cables:  sales@signalcable.com

Frank is a really nice guy. His stuff is rather inexpensive by any "audiophile" standard.
Still they work so amazingly good that it places the other manufactures on notice for their megabuck "productions" and "high-handed" claims.

Frank gives a 30 money back deal so you cannot go wrong...but burn-in is critical...it did require a bit of time...2 weeks, and then watch out....

Your knowledge of "digital" amps and their special considerations makes me realize that we must all educate ourselves in order to really know what is going on...

I cannot tell you how great the music sounds...deeply emotionally involving and sublime.

And you are quite right...the best is yet to come!

-Richard_