October 2001

Blue Circle AG 3000 Line Stage Pre-Amplifier
And AG 8000 Monoblock Hybrid Amplifier
Review by Bob Neill
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AG 3000 pre-amplifier and separate power supply (top)
AG 8000 monoblocks with their power supplies (bottom)

  Those familiar with Gilbert Yeung's BC 3 and BC 2 series, predecessors of the spanking new AG 3000 and 8000 sitting here in my house, have always known that the potential for an extraordinary accomplishment was in his hands. Gilbert's single-ended classics balance articulation, delicacy, authority, and presence to a degree that has caused more than one competing designer to ask, "What if this guy really turns his genius loose some day?"

Has he done it? Well, here's my score card:

(1) The AG combination has more power, more ability to resolve detail at all levels, and more absolute extension at both ends than the BC3/BC2 series.

(2) It has more overall authority and scale: its dynamics and strong bottom end enable it to recreate a more convincing presentation of an orchestra or jazz band. 

(3) It has more of its predecessors' overall balance, coherence, 'continuity,' integrity - you name it: the ultimate sine qua non the absence of which makes all other virtues meaningless.

(4) It does the near impossible for so highly resolving a machine: it brings so-so and even relatively poor recordings to life.

(5) It has virtually all of the touch, delicacy, immediacy, and air of the earlier series. The 'dual single-ended' topology of the AG 3000 seems to improve overall imaging and separation of forces which was already a BC strength.

Sounds like the whole package, doesn't it?

In my house the AG's are preceded by Naim's high resolution/high contrast CDX/XPS cd player and are driving the naturally warm, highly articulate Harbeth Monitor 40's with their 12-inch woofers. That means the AG's are getting a Leica-like version of the information and driving relatively insensitive (84 dB) Bentleys. And everything is traveling through superb Nordost SPM and exquisite Nordost Quattro Fil interconnects until it gets to Straightwire Virtuoso speaker cable for the last lap. So honesty urges me to remind you that the system as a whole is what I'm hearing. If I were a higher-powered reviewer with lots of alternative gear lying about, I could be more helpful here. I did send in a pair of Harbeth Compact 7's for the Monitor 40's, and while this is not exactly a match that makes economic sense, as an experiment it did reveal the same kind of improvement I hear with the Monitor 40's. They still sound like Compact 7's, but better Compact 7's, especially on the bottom. The trace of dryness in the upper mids is still there, but diminished.

What I have experienced over the two months or so that the AG's have been working together in my system is amazement, which was my chief impression when the AG 3000 entered, gradually superceded by respect. I was amazed by how much the AG package exceeded the very fine BC3/2.1 package; clearly I had not realized how much musical information those venerable beasts' eloquence withheld. The respect has come from the growing realization of how truly glorious 16-bit/44kHz digital can sound when a brilliant designer understands how to balance the many, often mutually exclusive demands high-end electronics place on him. Among the critical questions that had to be asked and then answered successfully -

· At what point does increasing power output begin to detract from retrieval of detail ? 

· Are absolute "slam" and 'speed' compatible with maximum "touch" and musical sophistication?

· How can you design a balanced, Class A/B topology for an amplifier so as to gain power and authority without loss of the immediacy, nimbleness, touch, and uncanny spatial magic of single-ended, Class A?

· How can you design a balanced preamplifier that effectively competes with a single-ended one at its own game?

· How can you design electronics that strike us as utterly truthful without making them also cruel to less than perfect recordings? Are there different kinds as well as different degrees of resolution?

There are other issues that Gilbert Yeung has obviously addressed that are beyond my limited technical intelligence to infer. I refer you to the Blue Circle website for a little more information on these matters. But even there, hard information is scarce. Gilbert has clearly broken some new ground with the AG's and is no rush to share the technical details. 

AG 3000

Where the BC 3 Despina, Galatea, and 3000 were/are single-ended, tube preamps, the AG 3000 is 'dual single-ended,' which means it is technically a balanced topology which behaves a lot like single-ended. There are two separate single-ended sections, each channel using a pair of 6922 tubes. (The BC 3 series use two 6922's which both serve both channels.) The AG has a huge power supply, which provides very noticeably increased control of my 12-inch Harbeth woofers. Overall, the AG 3000 is more authoritative in its presentation than its single-ended predecessors. This can be initially startling to someone accustomed to the BC series' gentler, more intimate presentation. Ultimately, I find it more convincing.

The AG 3000 has a slightly lower profile than the BC 3 series and wears a handsome two-tone walnut and purple heart face plate. Gilbert Yeung has the heart of Peter Morgan, who sold very few 4/4's and +4's without wire wheels and, of course, all had wood frames. The steel case comes in stock Blue Circle Blue but can also be had in stainless steel, black, or a designer color of your choice.. The matching power supply is the same size and the connection between them looks hardy and complex. As with the BC 3 series, there is no remote and there are separate volume controls for each channel - and actually two entirely separate controls per channel so that the positive and negative phase components of the audio signal in each channel can be controlled separately! There are both RCA and XLR inputs and outputs, but XLR is recommended all the way, which is how the unit is designed to operate at peak performance. Actually, since my Naim CDX is a single-ended machine, I may not have heard all the AG 3000 can do yet. If I get a fully balanced CD player in here for review later this year, I'll post a brief follow-up.

AG 8000

The balanced topology of the AG 3000 is a tip-off that in these new electronics Gilbert Yeung aspires to see what can be done with an all-balanced approach. With the BC 2 series of amps, he aimed to combine the undeniable virtues of single-ended, Class A, and hybrid technology. He was convinced that all three were essential to audio perfection and with the amps he made during the 1990's he made a strong case for that point of view. But toward the end of the decade his mind apparently changed. He began to find the expressive powers of both his preamps and amps limited or "incorrect," to put it in his own words. Furthermore, he was frustrated by the limitations of single-ended topology which offered immediacy and a sense of touch over (and at the expense of) authority - especially in the bass. 

The AG 8000 is high-biased Class A/B and true balanced - but still hybrid: tube input (a pair of 6922's for each monoblock), solid state output. Gilbert is not a fan of all tube amps but continues to believe that an all-solid state amp, even in so excellent an implementation as his new BC 8 monoblocks, stops short of the degree of musical perfection that is possible. Like many others, Gilbert has discovered that, past a certain point, power comes at the expense of detail. In the design of this amp, he found that point to be 150 watts, some 33% less than the BC 8's provide but, more important for many of us, 100% more than the BC 2 series. That he has forsaken Class A will be considered a blessing by most of us: Class A brings with it highly reputed but fairly subtle benefits. And Class A amps take an hour to warm up (I used to have to get up at 5:30 a.m. to turn on my BC 2.1's if I wanted good music for breakfast!); consume inordinate amounts of electricity; and put out great quantities of heat, which ultimately shortens the lives of their components. The AG 8000's warm up in minutes and run only slightly warm - seemingly forever. My sense of the 'amplifier world' is that the number of pure Class A amps is dwindling as A/B technology becomes more sophisticated. I don't hear much complaining about the demise of the Class A, SE Aleph amps from Pass Labs, do you? 

The AG 8000 has essentially the same dimensions as its all solid state, more powerful, and less costly brother, the BC 8 - though with the AG's there are four chassis, since the power supplies are separate: 9" x 9" x 22." All four chassis share the AG 3000's elegant wooden faceplate. XLR inputs only, though adapters are supplied for single-ended use. Two sets of speaker lugs for shotgun bi-wiring.

How Good Are The AG 3000/8000 Really?

Every CD I put on now interests me more. I find myself more attentive, to everything. It is harder to turn away. Instruments have more individual character. Ensembles are detailed as well as coherent. Most CD's sound slightly different from how they have sounded in the past. 'Authentic' instruments on Andrew Manze's Handel Opus 6 (Harmonia Mundi) have a new natural exuberance, eccentricity, and brio that is more exciting than the pretty and airy sound they had with my BC 3 and BC 2.1's. On the other hand, Les Ars Florissants' recording of the same work (Harmonia Mundi) is more beautiful and refined than I remember it. Kenneth Gilbert's Couperin harpsichord suites (Harmonia Mundi) - a dream on vinyl but a painful and cranky disaster on CD - are fulsomely redeemed. Les Ars Florissant's Purcell Farery Queen (Harmonia Mundi), which always sounded a bit muffled and vague before, is now closer to the lovely, lyrical, and witty thing I heard them perform in Jordan Hall. Harnoncourt's Bach Cantata series (Teldec), especially the early volumes recorded on analogue tape (Volume 1, 1971) have got their crisp and boisterous elegance back. Koopman's currently in process series of the same works (Erato) has more spatial presence and air than it had on my BC 3/2.1 gear. And finally, reissues of early Blue Note jazz recordings are somehow fresher and more frank than I remember them, the dry and reverberant acoustic mainly gone. This ability to reclaim older and so-so recordings is the aspect of the AG's that strikes me as their major miracle. I suspect that's the accomplishment that will baffle Gilbert Yeung's competition the longest. 

A select few small scale baroque recordings - Lully's Petit Motets (Harmonia Mundi), Clerambault's Motets pour Saint-Sulpice (Virgin Classics) - though delicious still, may be a little less holographic than I remember them being on the BC 2.1's. Is this the trade-off with A/B balanced? How much of it is the switch from mini-monitors to maxi's? Is it an artifact associated with the 2.1's or something real? I can't answer these questions. In both cases, the overall presentation impresses and finally pleases me more than it used to, so I have to say that the subtle absence of intimacy? sensuality? is clearly worth the cost of improvements in every other area, in my house.

And then, the critical tests passed, on go the new Alison Kraus (Rounder), Karrin Allyson (Concord), William Walton String Quartets and Frank Bridge Trios (Black Box), Volume One of the Legeti Project (Teldec), and the final volume of the Clerks' Group Ockeghem series (ASV). Bravo! Game Over. As close to musical bliss and perfection as I hope to get. And a Naim CDS2 and Nordost Valhalla is "in the mail." These are surely the good old days.

Any Quibbles?

Not really. Two matters of taste and one of economics.

(1) Paired with the Harbeths, some may object that the AG's are not particularly "fast." (They don't race Bentleys any longer.) That has mainly to do with a question of how fast natural is and what other qualities are compromised or lost when you design for ultra zip. To my ears they are comfortably within the natural speed limit. 

(2) Again, on a few extremely intimate, small-scale recordings, there seems to be a touch less palpability than I remember on the BC 2.1's. Sometimes 
noticeable, sometimes not. I include this quibble for the sake of credibility. As I 
say, ultimately, it's become a non-issue for me, who, as a rule, am generally a palpability/holography freak.

(3) They cost $26,000US (retail) for the combination. Money, money - no way around this one. If you're not poor and believe, as I do, that the preamp and amp are the heart of a truly musical audio system, you're at least one step on the way. Is it as important as a car? Of course. Will it last as long? Way longer. Over the past few years, I have found that putting around 60-65-% of the money into the electronics is the most cost-effective way to reach The Goal - not counting cable, which I do count highly. You don't need to spend more than $8K for a cdp to get superb sound. There are extraordinary speakers around for $6-10K. But electronics are another matter. As cavalier as it can't help sounding, I think $26K for electronics like these while unquestionably very steep, is not excessive, which tells you what class I think they're in.

Speaker Pairings?

Any of the 'natural family' should do fine. The winsome wallflowers from the UK - all present and future Harbeths and Spendors, especially the Monitor 30's and 40's and the SP 100's and the SP ½'s too, though for the latter the AG's might be overkill. Ariels, especially the 10-T. Matrix B&W's (802's for sure, probably worth trying on 801's - don't let the 150 watts output fool you, these babies produce a lot of current), Sonus Faber Guarneri's and Amati's, for sure. I would love to hear them on the Amati's. Whether they can redeem unnatural speakers - the Xpressssssive, Emotive, ASSertive, clinical, or the acidly etched - as gracefully and cunningly as they do so-so recordings, I have no idea. I wouldn't put it past them, but neither would I wish it upon them.

How Good Are The AG3000 And AG8000 Really?

Honestly, I have no idea. They have taken me to the limits of my critical range. Overall, I have not heard better and have no inclination to look further. Those with access to Lamm 1.1 hybrids, ARC monoblocks, Atma-Spheres (the big ones) etc. - all with their appropriate mates, will have to take it from here. That's the class we're in.

Okay, to the numbers. It is very hard to separate the AG's from the rest of the system, especially the Harbeths, since they do not project sound far out into the room nor beyond the speakers. If you sit at the apex of an equilateral triangle - in my case 9 feet on a side - imaging and soundscape with the AG's and Harbeths is pleasingly natural rather than dramatically so. So my less than perfect grades here have more to do with absolute achievement rather than what feels correct. A reminder: I consider 90 an extremely good grade.

Specifications

AG 3000

Inputs: two, both XLR
Outputs: two, both XLR
Maximum Output Voltage: 75V rms
Dimensions (each unit): 17" x 14.5" x 3.25" (WxDxH)
Pre-amplifier Weight: 22 lbs.
Power Supply Weight: 35 lbs.
Price: $11,500

AG 8000

Four separate chassis: two amplifiers, two power supplies
Power Output: 150 watts into 8 ohms 
Topology: true balanced 
Tube input stage: two 6922's
Output Stage: solid-state
Binding Posts: two pairs for bi-wiring
Chassis: stainless steel, powder coated BC blue steel cover standard. Other colours or stainless steel covers are available as options
Faceplate: solid wood, purple heart and walnut laminated faceplate
BCC1.0 isolation cones standard
Parts: custom Blue Circle polypropylene cap bypass
         in both B+ and low voltage power supply 
         Over 300,000uF power supply 
         2500 watt power supply transformer 
         DC power connection rated up to 34 amps 
         HexFred Ultra Fast Soft recovery diode in B+
         and low voltage power supply 
Dimensions: 10.5" (267mm) x 9.5" (241mm) x 22" (559mm) 
Weight: amplifier 30lbs.
            power supply: 40 lbs.
Price: 14,500 per pair

Company Information

Blue Circle Audio, Inc.
RR#2 Innerkip, Ontario
NOJ 1MO Canada

Voice: (519) 469-3215
Fax: (519) 469-3782
Website: www.bluecircle.com