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Positive Feedback ISSUE 21
september/october 2005


blue circle audio

NSCS integrated amplifier

as reviewed by John Acton






ProAc Tablette Reference 8 Signature (primary) and Quad 11L l (secondary).

Bryston B60 SST and Audio Zone Amp-1 integrated amplifiers.

SimAudio Moon Nova CD player.

Analysis Plus Solo Crystal Oval interconnect (1 meter, RCA), Analysis Plus Oval 9 (bi-wire, 8 feet), Custom Power Cord Company HCF 2 Special (CD player), and Custom Power Cord Company HCF 2 (amp).

ASC Tube Traps in front corners (5 feet tall; 16" diameter) and ASC Studio Traps (2) behind equipment rack on front wall.


Gilbert Yeung, owner of Blue Circle Audio, doesn't give review samples to just anyone. Prospective reviewers are extensively interviewed, subjected to lie detector tests and background checks by the FBI and Interpol, and then, just to make sure, Yeung personally delivers the review sample. Okay, I'm kidding—sort of. Yeung does interview prospective reviewers via e-mail, phone conversations, and/or in-person visits, and, whenever possible, he does deliver the component.

Why this rare level of attention and concern regarding the review process? Because Gilbert Yeung cares. That's not to imply that other manufacturers don't care, but Yeung does. He cares enough to hand-build his components to order, he cares enough to work with customers on reasonable customization requests, and he cares enough to select the dealers and reviewers that he feels understands the goals of his company—to bring people and music closer together.

Yeung is not into gear, he's into music, and it is only necessary to look at his creations to see that. Eschewing conventional massively-constructed casework and black/silver color schemes, a Blue Circle product is more likely to be finished in green with a red MDF faceplate and wooden knobs. Yeung also steers away from circuit boards in favor of component-to-component wiring and radical circuit layouts. The NSCS is Yeung's latest integrated amplifier. Entirely solid-state in nature, the NSCS is a much-upgraded version of the company's well-received CS integrated. Aside from the similarity in names, however, the NSCS does not have much in common with its little brother. Its power output is more than double at 110wpc into 8 ohms, the preamplifier section has a larger, more robust power supply, and the amplifier section takes advantage of Blue Circle's Truly Balanced Output Technology, whereby the negative loudspeaker terminals also supply current to the speakers for more control over transducer motion. A 600VA toroidal transformer powers just the amplifier, and that, combined with over 100,000 microfarads of capacitance, gives excellent current delivery.

Options on the NSCS (at additional cost) include single or dual Shallco stepped volume attenuators, remote volume control, and processor loop inputs/outputs. As I said, Yeung will accommodate other reasonable customization requests. Blue casework with a silver faceplate and wooden knobs is standard, but many options (some at additional cost) are available. The back of the amp contains three single-ended inputs, preamp outputs, and a tape loop, along with a pair of hefty five-way speaker binding posts and an IEC power cord inlet. The front of the amp contains source selection, balance, and volume control knobs, along with toggle switches for power and the tape loop. The preamp section is powered up even when power is off, to ensure stable operating temperatures and maximum performance of the critical low-level circuitry. The Blue Circle emblem, which lights up when the amp is fully powered-up, completes the package.

Yeung delivered the NSCS to my home, so there was no possibility of shipping damage, but the amp was well packed in a large box with soft foam packing material. An instruction manual and nondescript-looking power cord were supplied. The review sample had the standard silver faceplate and wooden knobs. The only upgrade from the base model was the single Shallco stepped attenuator.

The NSCS is fairly large (17.25 inches wide, 3.5 inches tall, and 14.25 inches deep), and heavy (45 pounds), but I had no problems installing it in my system. While the amp runs extremely cool, Yeung recommends that it be left on to ensure best performance, so that's what I did. The manual is well written, and provides installation details and a guide to operating the controls. The warranty is three years, parts and labor. No specifications are listed.

The review sample had seen plenty of duty, so I did not expect that additional break-in would be required, but due to a mishap involving the spilling of coffee by the previous reviewer, Yeung had just replaced the right channel output stage, so he suggested that I leave it powered up for a week before doing any critical listening. I did exactly that, playing music on repeat for 50-plus hours.

How did the NSCS sound? Like someone had injected my system with Miracle Plant-Gro. I heard the same astonishing immediacy and transparency I'm accustomed to, coupled with explosive dynamics and a new sense of ease that made my system sound larger, more effortless, and more natural. The midrange was clean and pure, with a slight bloom that was reminiscent of a tube amp's. The treble was extended and clear, with no trace of grain, edge, or coloration. In a word, the NSCS sounded superb. 

I was stunned by King Crimson's first album, In the Court of the Crimson King (Virgin 7243 8 48099 2 8). Greg Lake's voice on "Epitaph" and the title track floated above and between the speakers, with warmth, richness, and realism. The cymbal work was grain-free and clean, with a perfect mix of stick and metal. Instruments were superbly placed in the soundstage, and I really got sucked into the performance.

Anyone who likes 70s-era Berlin-school electronic music a la Tangerine Dream will find Radio Massacre International's Republic (Centaur CENCD 018) to be an aural feast. Mellotrons? Check. Sequencers? Check. Psychedelic electric guitar? Check. With the NSCS, the soundstage was enormous, dynamics were limitless, and there was an engaging musicality that had me transfixed in my chair for the CD's entire 74 minutes. There is a scene in Terry Gilliam's movie Time Bandits in which the protagonist, a 10-year-old boy, is awakened by a rumbling sound from his closet, followed by a medieval knight exploding out of the closet into his bedroom. As the pulsating sequencers built to a frenzy in the middle of "Raw Cane Approach," I felt like that boy as I waited for the music to come crashing out of the wall behind the speakers. When the electric guitar joined the fray and began dancing around the soundstage like a possessed dervish, it dawned on me that this is what high-end audio is all about.

I've listened to Yes' Close to the Edge (Atlantic R2 73790) hundreds of times since discovering it as a teenager. There is nothing like the nascent wonder of hearing a record the first few times, but listening to this amazing music with the NSCS in the system, I felt as though I were hearing it with fresh ears. There was a subtle increase in the air around Bill Bruford's cymbal work, and the greater purity and bloom of Jon Anderson's vocals laid bare the diction and emotional intensity of his singing. More than that, though, there was a musical "rightness" that made me feel like I was spending time with an old friend I hadn't known I'd missed.

The NSCS deftly avoided the cold sterility that can plague some solid-state designs. There was a subtle bloom and warmth to the midrange, coupled with a slight reticence in the upper midrange that drew focus to voices, guitars, and other midrange instruments. On the CD Out of Season (Go Beat 066574-2) by Beth Gibbons and Rustin Man, there was a palpable presence to Gibbon's voice on "Mysteries" and "Sand River," and the harmonica accompaniment on "Drake" sounded alive in my room. I found this aspect of the NSCS to be reminiscent of tube amps, but I don't mean to imply that the NSCS sounded colored—there was no bloating or thickening of tonality or texture that suggested any deviation from neutrality.

The NSCS handled soundstaging well. It created an appropriate portrayal of depth and height, with well-delineated images. Vangelis' China (Polydor 813 653-2) really showed off this aspect of the NSCS' performance. On "The Plum Blossom," the piano was inside and behind the left speaker, surrounded by plenty of air and ambience, while the violin soared above and inside the right speaker. It was spooky how in-the-room the instruments sounded. This album also allowed the NSCS to display its dynamic abilities. The microdynamics in Vangelis' piano playing on "Plum Blossom" were realistic, while the huge macrodynamic swings present in "Chung Kuo" and "Himalaya" were superb. The amp seemed to possess limitless reserves of power.

Rush's Signals (Mercury 314 534 633-2) was recorded in 1982, when digital recording was still in its infancy, and it sounds flat, compressed, and somewhat lifeless. The NSCS didn't transform the recording, but it permitted me to hear through its defects to a surprising degree. I could hear more three-dimensionality in Geddy Lee's voice, and while the instruments remained crowded together in terms of depth, I could hear a semblance of space between the voice, bass, and drum kit. The NSCS' pure, extended, and clean treble helped to cut through the digital sheen of the cymbals, allowing me to hear more metal, less glaze. I found myself enjoying this CD more than I have in a long time.

When I compared the NSCS to the Audio Zone Amp-1 (see that review here), the greater current capabilities of the Blue Circle amp quickly made themselves apparent. The NSCS's bass was tight, controlled, and as extended as the ProAc Tablette Reference 8 Signature and JAS-Audio Orsa loudspeakers would allow (see that review here). The Amp-1's bass was slightly slow and soggy in comparison. While the image focus of both amps was excellent, the NSCS portrayed a larger soundstage. Like the Musical Fidelity X-150, the NSCS sounded larger than the Amp-1. Though not to the same degree as the X-150's, the NSCS' midrange sounded warmer than the slightly sterile midrange of the Amp-1. The NSCS surpassed both amps in the vivacity of midrange instruments. Voices sounded more present and more real with the NSCS. In back-and-forth comparisons between the NSCS and the Amp-1, the Amp-1 had a more direct and slightly more immediate presentation. It sometimes sounded as if it possessed slightly more transient speed than the NSCS. I've never heard another amp come so close to the Amp-1, which is remarkable in this regard, so this is high praise for the NSCS.

I really struggled to identify any significant drawbacks of the NSCS. It was as simple, elegant, and easy to use as it gets. The back panel even had the labels for the connections written upside down and mirror-imaged, to assist hookup when peering over the top. As much as I liked it, the NSCS' styling may not appeal to everyone. It also doesn't possess every possible feature, including a mute button, mono switch, or phase inversion control. Remote control is an extra-cost option. Sonically, I could find very little to fault. The NSCS doesn't possess the last degree of immediacy, though it comes very close, and its subtly laid back upper midrange could sometimes sound a little too distant and uninvolving. Nevertheless, the NSCS simply got out of the way, letting the quality of the recording speak for itself. Lastly, the NSCS didn't possess the midrange bloom and magic of its tube brethren, but that would be too much to expect. In short, this is an outstanding amp for the money, and I think I would have to compare it to much more costly competitors to expose any significant weaknesses.

The NSCS never draws attention to itself, nor does it detract from the musical message. At the same time, there is a subtle warmth and midrange bloom that illuminates voices and other midrange instruments, and prevents the amplifier's overall neutrality from crossing over into a musical sterility. The raison d'etre of this amplifier is to serve the music. The NSCS casts a musical spell over the listener that is hard to forget. I've not heard another solid-state integrated amp at or near its price that is its equal. John Acton

NSCS integrated
Retail: $2495, review sample (with the optional Shallco stepped volume attenuator) is $2770.

Blue Circle Audio
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