Blue Circle Audio SBH Headphone Amplifier
he Blue Circle SBH headphone amp is a reasonably priced two-chassis unit that adds basic preamp functions to its main duty as a headphone amp. I asked Blue Circle head man Gilbert Yeung why he chose the two-chassis route over the more conventional -- and less-expensive-to-implement -- single chassis. He responded with two words, repeated several times, "Low noise, low noise, low noise." Ive seen both headphone amps as well as preamps that use two chassis to keep electrical contamination from the power supply from potentially corrupting the delicate analog signal, and I have to say that when such products are designed correctly and use quality wire and connectors, they can offer just enough sonic benefit to justify the price increase that two separate chassis add.
When I asked Gilbert what prompted him to create the SBH in the first place, I was slightly unprepared for his answer -- though I shouldnt have been, as its typically Gilbert. Seems one of his employees was looking for a headphone amp and bemoaning the fact he couldnt find one he liked. He finally settled on a popular European unit that he allowed Gilbert to take a listen to after he received it. Gilberts response was, "Yeah, its a headphone amp, but whats so special about it?" With that question in mind, and his natural curiosity in overdrive, Yeung used an old cookie tin as the chassis for his first prototype. From those humble origins, as they say, the SBH was born.
The SBH's two chassis are very similar in size. Both are powder-coated black, but the power supply is taller and fairly Spartan-looking. The umbilical between the power supply and control unit is blue stranded wire and long enough to keep the two well apart, which is how I arranged them. But I can see them sitting side by side if that is the only way you can accommodate them. Yeung told me that there is nothing innovative about the design of the power supply -- it's just a standard Blue Circle power-amp supply scaled down for use in a headphone amp. But as he noted, its big enough to do the job with room to spare. About the only items on the outside of the power-supply chassis are the XLR connector for the umbilical to the control unit and an IEC receptacle for either the supplied power cord or one of your own choosing. The back of the control unit offers two sets of gold-plated input jacks and one set of gold-plated output jacks, along with the XLR for the umbilical, which looks remarkably similar to Kimber Kable, although knowing Gilbert its undoubtedly of his own design.
Centered on the front of the control unit is the round Blue Circle logo, which illuminates when the unit is powered on -- which is whenever the SBH is plugged in, as there is no on/off switch. To the left are two toggle switches with three positions: left for input one, right for input two, and centered for mute. Below the toggles are two gain knobs, one for each channel. Just below the logo and to the right is the single 1/4" headphone jack. Far right is the master volume control. If youre a couch potato, you can add remote volume control.
I also asked Gilbert what headphones hed used in designing the SBH, and he told me that he used everything from earbuds to various AKGs, Sennheisers, and Denons. Indeed, I had the feeling that the SBH would respond well to whatever 'phones I used with it.
fter giving the SBH a few days to run in, the first CD I played was one of my all-time favorites, Andy McClouds Blues For Bighead [Mapleshade CD 07832]. This live-to-two-track recording offers the feeling of being present in the studio that few other recordings can equal. Using my reference AKG K-701s and the SBH, I felt like I was sitting next to Mapleshade owner and chief engineer Pierre Sprey at the control desk, so palpably real was the sound. McClouds bass was full, rich, deep, woody, and solid. In other words, it sounded as right as Ive ever heard. Steve Nelsons vibes had the muted hammer sound as well as the shimmer of high frequencies as they wafted off into the studio atmosphere. Victor Lewiss drum set had the requisite snap, crackle and pop of the real thing. But the real highlight of listening to this disc through the SBH was the sense of space. The feeling of hearing a room full of actual musicians performing was almost overwhelming. If the SBH could consistently offer this level of sound quality for its price, I thought, it might be a proverbial giant-killer -- a product that improves upon its much more costly competition, and in no small way.
I slipped Marcus Millers M2 [Telarc CD-83534] into the Oppos tray and heard the same deep, tight bass as I had with the McCloud disc, but now it was presented with the distinctive purr that accompanies an electric bass. I was treated to an instrument that, again, was realistic in both its own scope as well as the space around it. There was also a very real feeling of Millers fingers plucking the strings -- the quick, almost explosive force of the notes projecting into the recorded soundscape.
Acoustic instruments were a real joy to hear with the SBH. Livingston Taylors Ink (CD, [Chesky JD162]) was a case in point. The twin acoustic guitars on this CD were clearly separated by the tone each player pulled from his instrument as well as their locations in the soundstage. The tone of each was true and fully textured, and the sound of fingers plucking strings and exciting a large wooden cavity was as realistic as Ive heard -- via headphones or not. I admired the way the SBH handled both the initial transient and decay of individual notes. Listening to Soulfarms Scream of the Crop [Desert Rock Records 26-6] brought this point home to me. The "Intro" contains some extremely well-recorded percussion instruments that are being hammered on by mallets as well as the usual sticks. It was simple to discern the difference in the transients produced by each. The stick provided a sharp crack, while the mallet was more muted but no less quick in its attack. The decay of each seemed to waft into blackness equally.
Another strong point of the SBH, perhaps due to its large separate power supply, is the way it handled dynamic contrasts. It could go from soft to loud in the blink of an eye with no sense of discontinuity. It never lost its composure or ran out of steam, no matter how loud or complicated the music became. As an example, Aaron Coplands Fanfare for the Common Man from the Reference Recordings CD Copland 100 [Reference Recordings RR-93CD] is short piece all about dynamic contrasts between the instruments, and the SBH sorted it out without breaking a sweat. The horns had the requisite burnished brass bite and blat, and the percussion was loud, tight and deep, setting the perfect foundation for the piece. Again, no sweat for the SBH.
Vocals sounded both linear and dimensional. Livingston Taylors voice was so real I could easily discern the similarities -- and differences -- between it and that of his more famous brother, so present and three-dimensional was it. Female voices were just as equally well handled. I love Alison Krausss voice. Reproduced correctly, there is an ethereal quality that shines through. The SBH reproduced that quality in spades. I listened all the way through the CD Paper Airplane [Rounder 11661-0665-2] simply because I couldnt tear myself away, so enjoyable and realistic were the vocals.
The level of resolution the SBH could pull from each disc was high. I have been fortunate enough to receive both the CD and DVD-A of Sarah Pierces latest recording, Bring It On [Little Bear Records 14242, DVD-A by special request]. The SBH was easily able to demonstrate how all the extra resolution of the DVD-A made the music both sound and feel more real. There was greater space, along with greater fullness and texture to the instruments and a sense of three-dimensionality to the vocals that simply eluded the very good Red Book CD. The SBH wasn't the last word in clarity, however, presenting a slightly less clean window into the music than other pricier amps I've used. This made for instrumental tone and texture that was not quite as pure -- as singular and distinctive -- as the best Ive heard.
The SBH found the middle ground between the often cold and sterile sound of solid state and the warm lushness of tubes. There was nothing that wowed on first listen, which is a good thing, as products that grab your attention initially usually lose it shortly thereafter, when the wow wears off. No, the SBH simply reproduced music in a manner that made listening to music fun -- and that, to my ears, is what any audio product should do, and it's the highest compliment I can pay.
It also didnt seem to favor one set of headphones over another. As noted, I did the bulk of my listening with my favored AKG K-701s, but I also spent time with my Audio-Technica ATH-AD700s and Beyerdynamic DT-770s to hear how well the SBH stood up to different loads as well as how it interacted with each set of headphones. The SBH didnt let me down. I was reminded once again why I love the K-701s, as they came across as well balanced and musical. The ATH-AD700s were also well balanced, although sounding lighter than the AKGs. The Beyerdynamic 'phones were more closed in, darker and weightier, exhibiting deeper bass. In other words, each headphone sounded like I expected it would with little editorializing from the SBH.
Compared to my Original Electronics Master headphone amp ($200), which also has two chassis, the SBH was simply better in every way. Its bass was deeper with more texture and, for lack of a better way to put it, greater realness. Its midrange was far more open, pure and immediate-sounding. The top end of the SBH allowed the treble to shine in a manner that more closely resembles listening to the real thing. Plus the SBH conveys a sense of space that is not only noticeable but realistic if the recording contains it. It is plain and simply a better conduit between listener and the music. Then toss in the multiple inputs and output abilities and it walks all over the Master. Simply put, everything that the Master did well, the SBH did better -- and not by a small margin either.
he Blue Circle SBH took me almost all the way to the best sound Ive heard via headphones for a fraction of the cost. It tread a line between coolness and warmth that I appreciated, and it allowed me to hear differences between different recordings -- delivering all of this far better than any other headphone amp Ive heard at even close to its price. It would make a fine addition to an ever-evolving audio system or a private listening system -- just headphones, your music and you.
Blue Circles Gilbert Yeung has shown once again that he has both the ears and the technical chops to create a piece of gear that stays honest to the music while holding the line on cost. To me, that is a win/win combination, and so is the SBH.
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