February 2006

Blue Circle BC501 DAC
Rejuvenate and rejoice in music!
Review By Todd Warnke
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  Sources are dangerous – and not just for Lewis Libby. See, sources influence, shade, color and distort every sound that comes out of your stereo. Wanna bypass your loudspeakers and room? Use headphones. Pre-amplifier? Use a passive network. And as for that most overworked tone tool of all, cables – well you can always hardwire your stuff together. But without a source you can't hear a single thing – which makes choosing the right source perhaps the single most important audiogeek decision. And if you want to multiply the stakes, try being an audiogeekreviewer^ฉ. Are you sure that the slightly thin midrange that you've heard over the last three or four reviews was always coming from those products? And remember when you noted that the deep bass on the Engulf & Devour Mark XX loudspeaker was a bit flabby and so checked and rechecked room placement, amplifiers and cables, and after concluding that your ears were right and so decided to run the review in spite of the inevitable heat that you knew would follow (like that's a new experience) – and then three weeks later when the new God's Breath Mark XXX CD player showed up and the bass flab went away (though the treble did get screechy as well) you realized that maybe, just maybe the great unwashed masses might have had a point about your ears being full of wax?

Yeah, sources are important. But the problem is that sources, like all audio equipment, are flawed and can only be listened to in a system full of other flawed components and so determining their ultimate qualities becomes an exercise in creative tail-chewing – which sounds much more fun than it is. So, with that as background, let's all watch as this audiogeekreviewer^ฉ fumbles all over himself (like that's a new experience) attempting to come to a firm conclusion about the Blue Circle BC501 DAC.

Details
Gilbert Yeung of Blue Circle Audio, in a short decade has turned out more than his share of classic products, and in my opinion none is finer than the BC6 single-ended, hybrid power amplifier that I have used as a reference for the last five or six years. From a beginning with a product line built around low output power amplifiers and tweaky pre-amplifiers, Blue Circle has grown to offer a full line of power, pre-amplifier and phono stages that has consistently received glowing reviews. Still, something was missing – a source. At shows Blue Circle has often demo'd using their in-house (i.e. not for sale) test-bed DAC, the AG9000, but with the release of the BC501, Blue Circle has completed their electronic lineup.

With a full-size chassis (17.25 inches wide, 3.75 inches high, 16 inches deep including the input selector), the BC501 is a solid and solid-looking piece. Round back the Blue Circle is nothing if not accommodating with three digital inputs – ST optical, RCA, and AES/EBU – and two outputs – single-ended RCA and balanced AES/EBU. The power cord receptacle is a hospital grade Neutrik-styled adaptor (Blue Circle supplies its own power cord). The front panel has the familiar glowing blue circle in the center that lights up when you power her up. The left side of the panel has an LED to indicate de-emphasis, and a toggle switch to select phase with an LED to display your choice. The right side has a signal lock indicator and a large brushed steel input selector. It's an asymmetrical design, but when that blue circle lights up, it looks good.

Inside, the BC501 shows Gilbert Yeung's fanatical attention to detail as every part, wire and board is overspec'ed and finished to Swiss watch perfection. The DAC itself is a 24 bit, 8x unit in a BiCMOS sign-magnitude architecture. What that last part means, you'll have to ask Mr. Yeung directly, but the claim is that this design greatly reduces digital noise resulting in great detail retrieval and a lower noise floor.

To discover how good the BC501 is, I used the following gear. Other digital sources were a Cary CD-303/200, a Berendsen CD1 and my extremely customized Assemblage DAC1. The reference pre-amplifier was my First Sound Presence Statement while a ModWright SWL 9.0SE also saw a considerable amount of time in the system. Power came from an Art Audio Carissa and a Blue Circle BC6, while loudspeakers were my reference Merlin VSM-Ms, Triangle Antals, Audiophysic Scorpios and DeVore Fidelity Gibbon Super 8s. Cabling was from Cardas, Acoustic Zen, Audio Magic, Stereovox and Shunyata Research – who also supplied power conditioning. With all that out of the way, the real question is, what does it sound like?

More Details
First, let me point out again that I have used a Blue Circle BC6 power amplifier as a near constant reference for about 7 years. Why, and why not one of the more recent Blue Circle amplifier designs? First, because the BC6 is one of a mere handful of truly great audio products to come from the ‘90s. It was so good that in its power and price range I have yet to hear any solid-state amplifier its equal, much less anything that bests it. The reason the BC6 is so good may be because Mr. Yeung has consistently does his finest work on small signal devices or at least on devices where everything can be run flat out – so the hybrid (tubed input stage, solid-state output stage), pure 'Class A,' 25 watt per channel BC6 allows Yeung to do what he does best, which is deliver a high purity signal loaded with detail and dynamics, but also one that delivers a direct dose of 100 percent of the emotion in any particular recording. In listening to Blue Circle over the years I have nearly always heard that same sound in their pre-amplifiers – as have others as they continue to receive constant, positive reviews for their pre-amplifiers – but when the company moved to higher powered, non-pure class A amplifiers in the late ‘90s I felt they lost a touch of the emotion on the power side. In the last several years they seem to have found their way back with the big amplifiers, and so I have been interested in checking out their power products again. But when I saw a commercial DAC from the company, given their past history with small signal devices I knew it had the potential to be real special. Which brings us yet again to the main point here, what does it sound like?

Well, in a word it sounds natural, and if you've been bored enough to read my opinions over the years you know that is about as high a piece of praise as I can summon. Then again, even if you have been following events at the Warnke Music and Hiking Lodge I'm guessing you want more info, so here goes.

Deeper Details
At the top end the BC501 has the absolute best treble I've heard. Its dynamic scaling is explosive and yet never, ever brittle, sharp or thin. This is not a skill to be slighted. Go listen to live, acoustic music and you'll hear a lot of treble information, much of it at high SPLs (cymbals anyone?) and yet, while it may startle, it's not the ear bleeding stuff we usually get from our stereos. Think about that for a second – when you listen to live music it is usually the bass that constrains how loud you can listen and enjoy, but in your listening room it is usually the treble that makes you leap for the volume knob. Well, with the BC501 that was not the case. Take a song like the Jeff Buckley track "Last Goodbye" from Grace [Columbia CK 57528] which opens with little guitar riff in the right channel, adds a chugging bass line and then leaps into action with a spray of cymbals. Through my Assemblage this spray is like an icy wave crashing over the bow of on an Arctic trawler, but with the BC6, though just as loud it is like the warm surf smashing into you at the beach. You want less a poetic description? Ok, with the Assemblage in the system the volume limit for the song is set by those cymbal splashes as they have a leading edge that is harder to listen to than real cymbals, but with the BC501 the track can be played louder because the cymbals can leap up in volume without hurting your ears, whilst also retaining a pure and natural timbre – just like the real things.

Dropping down the spectrum, the mids of the BC501 have that smooth, continuous quality that blurs the line between digital and analog. Feed the BC501 a great recording, like the Charles Lloyd disk, The Call [ECM 1522], whose opening track "Nocturne" begins with gentle cymbals, a lovely tenor solo by Lloyd and a flowing solo by Bobo Stenson on piano, and you can hear what I mean. Lloyd's sax is rich with harmonic information, fully fleshed out and vivid. Reed and metal exist as separate entities and yet combine to create a warm, inviting and very real tonality. Stenson's piano, likewise, is string and wood with each part detailed, but conjoined in song as well.

Bass, even on some of the more driven and bizarre electronica I enjoy, is taut and scarily tuneful. Lustmord's The Place Where the Black Stars Hang [Side Effects DFX 16] is full of dread, even on a boombox, but with the BC501 the deep bass machine throbs are revealed in full glory – the processed but recognizable sounds are placed so far back in the stage that they seem like a nightmare and yet are so real that your palms begin to feel clammy. Good stuff.

Back in the real world, the 1986 film Round Midnight [Columbia CK 40464], besides reminding America of Dexter Gordon, featured an amazing lineup in a live recording that just blazes. Bass duty is shared between Ron Carter and Pierre Michelot, and both shine. The version of How Long Has This Been Going On from the original release opens with Herbie Hancock down low on the keyboard and then continues with he and Michelot sliding in and out of sync as they play a similar low bass pattern. Through the BC501 the subtle textures of each instrument was easy to pick out, and yet not so analytical that the music was lost.

Dynamically, the Blue Circle is a good ‘un. As I mentioned earlier, the treble scales from ppp to FFF with snap and drive. Likewise the mids showcase all possible ranges in volume with ease. Bass, at least in my system, was very linear but lacked just a touch of the explosive power that the BC501 was able to deliver in the upper ranges.

If you've been following along at home, you know I'm not that much of a staging freak, though I enjoy the stuff when it works. In this regards, the BC501 more than met my expectations. Left to right spread was very nice, with dense and stable images. Depth, likewise, was far better than the norm and very solid. Images on the stage had particular beauty, resolution and grace.

Other Details
Compared to other players in my system, such as the Berendsen and the Cary, the BC501 generated a deeper emotional connection to music. This is not to imply that it lacked detail or warmed things up in a tube-like manner, to the contrary, it had a cleaner, more detailed stage than the other players – rather, the magic of the BC501 lies in that word I used earlier, natural, as the Blue Circle allowed me to sink more easily into the illusion created in my listening room. To be sure, the other players are skilled and each has at least one area where they show their heels to the BC501.

Compared to the BC501, the first thing the Cary makes you notice is its bass. Though a tonally even player, with linear dynamics, the Cary has deeper bass with slightly better definition and dynamics than the BC501. On rock and some jazz, this gives the Cary an edge over the BC501, but on everything else the superior mids and treble, dynamics and tonal purity of the BC501 takes over.

Since the Berendsen is still awaiting a formal review I'll limit my comments about it somewhat, but what the German player offers is a very coherent, sophisticated sound, with great detail and even dynamics. As compared to the BC501, it has a similar set of strengths with, perhaps, just a slight veil over the top but with deeper bass reproduction. In the end I preferred the slightly more open, more detailed and more emotionally direct BC501, but the strengths of the Berendsen are very seductive.

Final Details
I have spent a great many years listening to Blue Circle gear and have come to appreciate the care Gilbert Yeung lavishes on his products. Naturalness and purity are long-term hallmarks of his designs, and the BC501 confirms its lineage. The BC501, like the BC6, is the perfect combination of a reviewer and music lover tool. Want to explore a recording? The BC501 is the perfect partner to pull out all the detail you want. But (more importantly) want to relax, rejuvenate and rejoice in music? There too, the BC501 is a willing and perfect partner. And at the performance the BC501 returns for the price, it is a steal. The ability to use up to three different digital sources is a real bonus – I often hooked both my computer and transport up at the same time. Add in a build quality that will assure a trip to the hospital (and not the repair shop) if you drop it on your toes, and you have a true digital bargain. Most highly recommended.

Specifications
Type: Stereo digital to analog converter

Front Panel: Selector switch / phase switch / signal lock, phase invert, and de-emphasis indicators.

Circuitry: Three power supply regulation stages, over 110,000uF capacitance filtering, separate digital and analog power transformers, custom designed AC filtering.

De-emphasis: Automatic

THD+N: <0.0009% measured at -0 dBFS

Inputs: AES/EBU (XLR) and S/PDIF (RCA), optional BNC,  ST Fiber-optical or optional Toslink

Outputs: Balanced 9XLR) and single ended (RCA)

Price: $3,695 with optional inputs extra.

Company Information
Blue Circle Audio 
RR2 
Innerkip, Ontario, Canada 
N0J 1M0

Voice: (519) 469-3215
Fax: (519) 469-3782
E-mail: bcircle@bluecircle.com
Website: www.bluecircle.com