Cambridge Audio Azur 840E Preamplifier & 840W Monoblock Amplifiers Review

Back to the 840E preamp

I suppose I’ve gone about this backwards, so I’ll speak now of the particular merits of the 840E Preamp. As enamored of the 840W’s as I am, the 840E is certainly not without its attributes. Upon first approach the audibly clattering volume control was repulsive. I thought it sounded like a toy Gatling gun, with its “Clack, Clack, Clack…” Surprisingly, I got used to its rapid-fire stepping rapidly, and now it is negligible. I would not have thought I would so easily dismiss a component’s operational noise, but as we accept faults in our partners in life, I chose to look past this small irritant. It is not so loud as to be perceptible when listening at moderate levels.

The cause of the noise is a volume control comprised of a passive resistor ladder switched by relays. Recently resistor ladders have come into vogue as improvements to preamp design. Since they incorporate no transistors they disrupt the signal less than attenuators. Matthew explains that the resistor ladders, “are configured so the signal doesn’t flow through the whole ladder all the time. Rather, the appropriate values are switched in to achieve the gain desired.”

One of the most sensible features of the 840E preamp is the ability to select for each input whether to activate the DIRECT in function. This bypasses the tone control circuitry, and it is a clever idea to isolate each input to suit tastes. A diminutive bass and treble clef icon on the display next to the input denotes that the music shaping circuitry is operative. The icon disappears when in DIRECT mode, which I used almost exclusively as it was a hint cleaner.

“Clarity Ability”

Let’s call the ability of the Azur series components to produce clean sound their “Clarity Ability”. Individually they exude a “no muck, no grunge, no schlock” character. Together the compounded clarity of the preamp and amps seems more than doubled. It vaguely reminds me of a visit to the Ophthalmologist at the point when he places sample lenses to the eye and says, “Which is clearer?” They’re both clear, but I have to choose one which I think is clearer. At some point my eyes get tired of the exercise and I feel like saying, “Just pick one! I’m driving myself crazy!”

Is it possible in audio to choose an option which seems too clear? I did that last time I selected glasses, ending up with ones which are not comfortable to look through long term as they are too “intense” on the eyes. I sometimes find myself going back to my old glasses to get a break from them. What seems to have happened with the glasses is that one lens must have an inappropriately stronger magnification than the other; one eye is off a bit.

I’m not out to fault Cambridge in the least, merely attempting to capture the sense of compounding “clean” sounding components in a system. For some listeners they can’t get enough of the “clean” thing. Tonality is not as critical as detail to them; we all must make our choice. They would put together a rig with highly resolving source, amplification, cables, and speakers. Others would say that’s too much detail and a little warmth or softness would be appreciated. The 840 series components approach “as good as you’re going to get” in terms clarity with SS performance.

However, if you are afraid to go “tubeless” I would suggest the insertion into the rig of a tube component. I highly recommend for sonics the just-released Ayon CD-2; it is proving to be a formidable player. I had previously mentioned the surprisingly warm sound of the Rowland Capri with the 840W amps. The one thing you will not want to do is bypass these amps. It would be better, if you must choose between them, to secure the amps and then search for the proper preamp. You will certainly not go wrong, however, with the 840E. Selection of the proper interconnects also can introduce a much more laid back sound.

Use of power cords on the 840E preamp and 840W amps

Be reminded that these amps take a 20A IEC. Don’t make the mistake of picking up aftermarket power cables with the standard 15A connector. There is another way to address the tonality of any preamp or amp which uses an IEC – swap out the power cords. One power cord properly placed can chase away a bit of stiffness. Using the 840E I always had two power cords handy, the Wire World Electra (copper) and the Silver Electra (silver coated copper). When I felt the “clarity compounding” was too strong I slipped the all copper Electra into the rig. If I changed out speakers or source and wanted a touch more “magnification” I reinserted the Silver Eclipse.

What this indicates on the whole is that the stack of Cambridge gear is both inoffensive and highly amenable to massaging for ultimate compatibility with sources and speakers. As “dead on” clean as they are they are not sterile in the least; they are clear but not crass. The Cambridge pre/amp(s) can be life savers for speakers which are, for lack of better words, “congested” due to design limitations. I wish dearly I had heard the Tannoy Glenair speakers with this assemblage. Likewise, the Wilson Benesch Curve would have benefited nicely from the frank, fair and forward approach of the Azur 840 series.

Can’t kill these things

The 840W is built with a suite of protective features which can save the life of the amp as well as the buttocks of the owner. Given the name “Cap5”, these safeguards include monitoring of the output stage by continuously measuring the voltage relative to the current, temperature, DC offset and comparison of the output to the input for signs of distortion. If something very bad happens the unit swiftly moves into protection mode. I know – I saw it happen.

You don’t try to fry amps and neither do I, but once in a while accidents happen. Mine was while trying to hook up the 840W’s to the just arrived King’s Audio “The King” speakers. These are low-efficiency beasts, having 83dB sensitivity and impedance as low as 1.8 Ohms. I still had the Cambridge amps in bridged mode and the thought of bi-wiring them to The King being a bad idea crossed my mind. However, I proceeded and upon turning them on heard a distinct, “Phhht”. That was it, just “phht.” The front lights of the amps danced, warning that it was in PROTECT mode.

At times like this one is tempted to freak out completely. After all, I hadn’t even listened to a single song and the amps were blown just by turning them on! I quelled the storm rising in my stomach, because after I had the incident with the temperature I did read the manual – thoroughly. I was well aware of the extensive protective circuitry in the amps, so I was fairly certain that the diminutive “phht,” meant the amp was recoverable.

Knowing that I had breached the amps’ capacity I rewired them to dual mono mode, which would make them far more tolerant of the low impedance load. Cycling them on again was a joy; absolutely perfect, like brand new amps! My friends, these protective devices in the amp are worth their weight in gold! What price would you pay for an amp which could hardly be killed due to a bumbling error such as improper connections? Matthew pointed out that in bridged mode the amp would be driving as low as a 1 Ohm load with a speaker like The King, and my bi-wiring put it beyond its capacity. Once reconfigured to the more stable dual mono mode the amps worked flawlessly.

An acquaintance of mine, who usually calls me up to configure his stereo, attempted recently to move his rig alone. He thought he had the wires all correctly labeled and reattached. He didn’t; the entire left side of the system was taken out by the surge – speaker, subwoofer, amp channels – the whole thing. Had the amp have protective systems similar to the Azur on board it likely never would have happened! A man like that will spend serious money to know he will never have a fatal accident with his precious gear. Cambridge seems to be very conscious of the masses who are petrified of wiring the rig wrong and destroying it. Thanks to Cambridge Audio we now live in an age when destruction of the amp by one misplaced wire is a thing of the past! I’ll not assert that every electronic disaster can be overcome by these amps, but I wouldn’t be surprised if most encountered by audiophiles would not stop the 840W.

World Class Speaker with Middle Class Amp?

I enjoy putting together unusual, stunning sounding rigs. I get a tremendous kick out of hooking up unexpected combinations of components to satisfy my curiosity. Sometimes, however, I am prevented from doing so by the constraints of reality.

January this year, Dagogo published my Legacy Audio Helix speaker system review. The version of the Helix I reviewed utilizes six channels of amplification. I was limited in the number of amps used, in fact one – the Rowland MC-606. That IcePower behemoth admirably footed the bill for power. But I can’t help but wonder what could have been, what might have been heard, if I could have secured a third Azur 840W. At the time of my request Daniel Jacques of Audio Plus Services was in short supply. I know he went over and beyond in securing two for me. I cannot thank him enough, as in bridged mode these are the best sounding SS amps I have used regardless of cost.

As things happen I learned the name of the person who was buying the same pair of Helix I used. I called him with one recommendation: Get a set of Azur 840W’s to try with the Helix. Yup, a bargain amp with best of breed speakers. Why? What fool would suggest such a thing? I would suggest it, and it would be based on the fact that the 840W can flat out drive a speaker with nearly unmatched purity. Whatever Cambridge is doing “floating” the crossover, it’s so good that I wouldn’t hesitate to recommend it for use with the best of speakers.

For those in the under $20K class of systems, this is a “must consider” setup. I will be clear about the priority; the 840C player and 840e preamp are both respectable, better than average. However, the amp is the champ, and it would be well worth it to pursue two of them. If I had to pick only one to own among the CD player, the preamp and the power amp, it would be the 840W amps, no hesitation about it. If I were putting together an affordable one-brand system, the Azur 840 series would be at the top of the list.

One of the things I love about a bridgeable amp is the potential for growth. Just as the Pathos Classic One MkIII has the bridgeable function, so also the 840W is bridgeable. It is a wonderful product which has the capacity to grow along with you. It’s better than almost everyone thinks. I like finding components with potential to surprise, with performance boundaries not yet discovered by most.

There may be some “mother of all amps” out there which can eek out more brute strength and another degree or two of purity, but for the money I know of nothing else I have heard either in my room or at shows which is superior in terms of flexibility of configuration, clean sound and that elusive quality of “musicality”. I’m not sure I’m ready to relinquish my beloved Pathi, but they’ll need to move a bit closer together. The Azur 840W’s are moving in and they will be busy!