February 1, 2010

Blue Circle Audio GDC Integrated Amplifier


GoodSound! and its sister website SoundStage! have offered a good deal of coverage of products from Gilbert Yeung’s Blue Circle Audio. The firm, based in Innerkip, Ontario, has a wide range of components, many in the higher-priced bracket. But as Yeung states on www.bluecircle.com, neither he nor his fans were happy when Blue Circle ceased production of its entry-level CS integrated amplifier. The CS’s successor is the GDC (starting at $1795 USD, depending on configuration).


Gilbert Yeung’s philosophy is that it’s better to spend money on a product’s sound than on its looks, and the GDC’s appearance is, unsurprisingly, stark. In fact, it looks a lot like Blue Circle’s BC707 and BC709 phono stages. If the GDC weren’t so slim (just 1.875" high), it would look good in a system built for Darth Vader. The front panel’s flat black finish is broken only by two knobs, for volume and input, a tiny chrome power switch, and, in the center, the company’s signature logo: a circle that lights up -- in blue, of course -- when power is applied.

The GDC’s other dimensions are a standard 19"W x 14.5"D. The case is made of heavy steel, but it’s the massive toroidal power transformer and other internal goodies that help the GDC tip the scales at 35 pounds. This is one solidly built amp. It’s claimed to output 95Wpc into 8 ohms or 140Wpc into 4 ohms, enough for most speakers and most rooms. The stated frequency response is 10Hz-25kHz, +0dB/-.1dB, at less than 0.25% THD (10W into 8 ohms). Noise is well down at 115dB vs. full power.

On the rear panel are: an IEC power connector with fuse; one set of sturdy but plain speaker binding posts; three pairs of gold-plated RCA input jacks; and a Ground Lift switch. This last is for use in case a ground-loop hum develops between the GDC and another component; flipping the switch will break the ground loop and stop the hum.

Blue Circle components are hand-built, and many options are available with the GDC: a USB input with built-in D/A converter; an RF remote volume control; JAFBP binding posts; a tape loop; a phono input featuring user-adjustable gain (60dB or 38dB); control knobs of stainless steel or wood; and a stainless-steel faceplate. The number of inputs can also be modified. You’d have to inquire for prices on these, as they vary. My review sample was of the basic model, with three line-level inputs labeled 1 through 3.


When the GDC first arrived, I was in the midst of reviewing the Simaudio Moon CD.5 CD player and Moon i.5 integrated amplifier, so I used the Blue Circle as a power amp for my office system: Sherwood CD-4050 CD player, Sangean HDT-1X AM/FM/HD tuner, JVC F-Q41 turntable with Grado Green cartridge, and McIntosh Labs C27 preamp. The GDC drove a pair of Celestion 3 speakers on Sanus wood stands, while the C27’s center-channel output was connected to the input of an Advent ASW 1200 subwoofer.

When I’d completed the Simaudio reviews, I moved the GDC downstairs to my main system, which hasn’t changed much recently; the primary source components are still a Dual CS5000 turntable with Shure M97xe cartridge and a Sony CDP-303ES CD player. Normally, these are connected to my Linn Majik 1P integrated amp, which drives my main speakers, a pair of NEAR 50Me IIs. In this instance, however, I connected the Sony CD player directly to the GDC with Linn cables and used the Majik only as a phono stage, connecting its preamp output to one pair of inputs on the GDC with Dayton Audio interconnects. Then, just as I was settling in to do some serious listening, I received a pair of Acoustic Energy Radiance 3 floorstanding speakers (review forthcoming), and added them to the mix.

I connected the Blue Circle to the speakers with 14-gauge AR cable. Because the GDC has only single speaker outputs, both the NEARs and the AEs were single-wired, though each can be biwired. AC power is supplied by a dedicated circuit feeding a PS Audio Soloist in-wall power conditioner and surge suppressor. My listening room is 17’L x 11’W x 7’H, finished in drywall (with makeshift wall treatments) and floored with cork, most of the latter covered by a 9’ x 12’ rug. Both sets of speakers were about 6’ apart, 25 to 26" from the front wall, at least 2’ from any sidewall, and 6’ from my chair. The NEARs fired straight ahead; the Radiance 3s were toed in about 10 degrees.


British reviewers often speak of "pace, rhythm, and timing." But I subscribe more to the words of the cofounder and, for many years, guiding light of Jaguar Cars, the late Sir William Lyons, who described Jaguars as being imbued with "pace, grace, and space."

The same could be said of the Blue Circle GDC -- and to "pace, grace, and space" I add "bass." From the very beginning of my listening, I was struck greatly by the pace of this amp: timing sounded absolutely right, from the bottom of the frequency range to the top. For instance, the line on the five-string bass that figures prominently in Fourplay’s "Baja Run," from Fourplay (CD, Warner Bros. 26656-2), sounded extremely tight and strong through the GDC. In "Corner Pocket," a great track from Count Basie’s Finest Hour (CD, Verve 314 589 637-2), the infinitesimal but noticeable lag of the horns and winds behind the rhythm section was crystal clear; there was no doubt.

Voices, too, sounded exceptional, and were the first indication of the GDC’s "grace": mids and highs were reproduced with incredible detail. I was particularly struck by the reproduction of voices in Manhattan Transfer’s version of Weather Report’s "Birdland," from Down in Birdland: The Manhattan Transfer Anthology (CD, Rhino/Atlantic D200146). Many mixing tricks are used in this track, including the panning of singers’ voices all over the soundstage. Through the GDC, each voice, no matter where placed, was rock-solid and pure. Another example was the mandolin accompaniment on Bruce Hornsby and the Range’s "Mandolin Rain," from The Way It Is (CD, RCA PCD-5904). The mandolin comes in near the end, and is mixed to stand out from the other instruments and Hornsby’s voice -- but until the GDC, I’d never heard it reproduced so clearly and precisely.

Then there was "space": The GDC’s soundstages were superior in width and depth to those thrown by any other amp I’ve heard in years. Logically, this shouldn’t happen; the reproductions of music by well-designed amplifiers should be pretty indistinguishable from one another. But the GDC was better. I pulled up a favorite, "Money for Nothing," from Dire Straits’ Brothers in Arms (CD, Warner Bros. 47773-2). Through some systems this track can sound fairly flat, the drums smooshed up against Mark Knopfler’s voice and lead guitar. Through the GDC, however, the soundstage was high, wide, and handsome. The drums were well behind Knopfler, the accompanying instruments well off to the sides, and Sting’s "I want my . . .," etc., up and to the right. It was a very revealing performance.

Finally, there was the bass. To quote the Who, the GDC produced bass lines that were meaty, beaty, big and bouncy. That modest-looking enclosure was hiding a lot of solid low-end impact. And the bass aligned with all four of the qualities mentioned in that album title. Fulfilling characteristics meaty and big, bass was solid and upfront; as for beaty and bouncy, its rhythm was first-rate.

It’s always a major delight to hear the bass line in Fourplay’s "Baja Run" reproduced by a good system, but the GDC offered a little something more: not more bass per se, but better-defined bass -- very precise bass that dug deep. Another great example was the bass line in the title track of Steve Winwood’s Roll With It (CD, Virgin V2 90946), which gets up and boogies hard. The GDC reproduced it with no sense of strain; it just did its job and got out of the way. I like that in an amp.

And speaking of strain: Although the NEAR and the AE speakers present a power amp with fairly complex loads at certain low frequencies, throughout my listening the GDC never became more than slightly warm.

In a long-ago review for another publication of my reference amp, the Linn Majik 1P, I noted that it was the first product I’d heard that could approximate the prototypical ultimate amplifier: a straight wire with gain. To some degree, the Blue Circle GDC surpassed the Linn in this regard. Most likely it was the GDC’s lack of strain in reproducing high sound-pressure levels (the GDC puts out 95Wpc to the Linn’s 33Wpc). The Majik’s pacing equaled the GDC’s, but the Blue Circle surpassed the Linn in grace, space, and bass. However, the GDC couldn’t ameliorate my main complaint about the NEARs: their over-the-top midrange. The GDC reproduced the signal faithfully. And that is its greatest strength.

Final thoughts

I really enjoyed having Blue Circle Audio’s GDC in my system. I’ve had the great good fortune to hear a number of really competent amplifiers in the last year or so, from Rotel, Marantz, and Simaudio. As good as all of them were -- and they were fine -- in the GDC Gilbert Yeung has created an amp that compares well with or even surpasses all of them. The GDC has a great blend of power and sound, and it can drive most speakers to which it might be matched with no problem. The basic model is a bit shy of inputs, but that can be addressed by Blue Circle. If you’re into the game of "my amp is bigger than your amp," the GDC will come up a bit short -- put it in an equipment rack and you probably won’t even notice it. But if your priority is fine, solid, realistic sound, the Blue Circle GDC is just the ticket.

. . . Thom Moon

Blue Circle Audio GDC Integrated Amplifier
Price: $1795 USD (base price).
Warranty: Three years parts and labor.

Blue Circle Audio, Inc.
Innerkip, Ontario N0J 1M0
Phone: (519) 469-3215
Fax: (519) 469-3782

E-mail: bcircle@bluecircle.com
Website: www.bluecircle.com