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The 022i Solid-State Integrated Amplifier
For those of you who have been following Gilbert Yeung’s audio creations for the last few decades, I think that you would agree that he
is always exploring new things… his thinking and imagination never stand still. He also refuses to espouse any dogma or creed. He has
designed single-ended class A amps, and A/B amps.  He has designed hybrid amps and he has designed breathtaking world-class
amps using op-amps back when most designers scoffed at the idea. He has designed tube preamps, solid-state preamps, and recently
he designed a cross-hybrid solid-state and tube preamp unlike anything available today. Gilbert follows his own path and is not really
influenced by what others think, neither does he tend to pass judgment on others’ work either… each to their own.

For the last few of years, Gilbert has been focusing on solid-state designs. The BC109 and BC107 preamps, the two NSLs and the NSP
power amps are some examples. That does not mean that he has abandoned tubes; solid-state is just where his curiosity has taken
him of late. The 022i integrated amplifier is the latest creation that has come out of this current focus.

This is the newest, and we think possibly the best, integrated amplifier that Gilbert has designed. It looks very simple, and we like to
think it looks rather elegant as well. There are only two controls on the front panel of the main chassis (volume and input select) and a
power switch on the outboard power supply. The 022i is a synthesis of two existing Blue Circle products: the BC1022 power
amplifier and the BC107 line stage preamp. Much of the design tech that went into these two products is found in the 022i. Here are
some of the details:
Let’s start with a Blue Circle signature attribute, the massive power supply. Actually there are two power supplies: one for the input
stage and one for the output. Each one has their own optimized circuitry. Combined there are over 920,000 μF of filtering or just under a
farad. This is unheard of in a mid-powered integrated amp. It is conservatively rated at 125 W into 8 Ω and 165 W into 4 Ω, but it sounds
and plays so much bigger than the numbers would suggest. This is a very powerful amplifier.

Here are a few more details about the power supply. The transformers are installed using silicone bubble isolation mounting to
mechanically isolate the transformers from the chassis. The output stage transformer employs core band technology. There is a
special sheet of silicon metal (referred to as a core band) surrounding the core of the transformer. This prevents the electromagnetic
energy produced by the transformer’s primary and secondary windings from radiating into the rest of the amplifier’s circuitry.  This type
of radiation is commonly referred to as electromagnetic interference or EMI. There is also a DC-blocking circuit upstream from both
transformers, similar in design to our RPD-15, but optimized for the 022i. DC offset can cause a large transformer to produce a
mechanical “growl” and it can also force a transformer to work in an unbalanced mode since the crossover point is no longer at 0 V.
If the offset is great enough, it may even cause the core of the transformer to saturate. Toroids, specifically large toroids, are especially
susceptible to DC offset problems. We are planning to add core bands and DC offset blocking circuitry to all future Blue Circle power

Like the BC107, the front end of the 022i is fully differential and DC-coupled. Volume is controlled by a hand-built stereo Shallco
attenuator using hand-selected and matched mil-spec resistors. The amplifier section employs the same fully-balanced M2 output
stage as the $10k NSP power amp. It is our humble opinion that there is some very special synergy going on here.

As to the types of inputs… that is totally up to you. You can choose four single-ended inputs, one balanced and three SE, or two of
each at no extra cost. If you want more than two balanced inputs there is an extra charge. If you want a processor bypass loop or a
preamp out, they are also optional. And of course if you have some special request, just let us know and chances are we can make it
The Tech
It has been an unwritten rule here at Blue Circle (and Gilbert gets very pissed when we break it) that we avoid publically talking about
how our gear sounds. First of all, what manufacturer is going to tell you that they have built something that sounds terrible, so why
believe anything they say? Secondly, evaluating a piece of audio gear is so subjective that it really isn’t wise to go by one person’s
opinion, especially one with a conflict of interest right from the get go like the folks that built it in the first place. There is a reason why
there are so many varied types of speakers, and electronics out there. People have different tastes and who is to say which ones are
more valid.

What we can say is that this amp is definitely different from the FtTH2, but not that different. Gilbert has always strived to make both
his tube and solid-state gear sound like music and not like the technology that is reproducing it. Over the years, both of his platforms
have been approaching that perfect middle ground between the two that designers strive for but never quite reach. But tubes definitely
do have a certain flavor to them. The FtTH2 is a bit sweeter than the 022i, but perhaps the 022i is a bit more honest. It really is a
matter of taste, but it is our opinion that with the 022i, Gilbert has moved closer to the goal.

When it comes to subjective evaluation, what we do is we let others (reviewers, dealers, and owners of our gear) share their comments
with you. That is why we have our online forum. Unfortunately, the 022i is so new that few have had the opportunity to spend a lot of
time with it. So, here are a few impressions from one of our long-time (and very knowledgeable) dealers who has lived with this amp for
some time now. You can read more of Bob’s comments, and read them in context, on the forum. Bob has been kind enough to let us
use a few of his insights with one caveat. He asked us to make it very plain that he is speaking solely as an individual and is not
speaking in any capacity as a representative of Blue Circle. As we get more comments and a review done (one is in the works) we will
share them with you. Here are some of Bob’s observations after breaking it in for about a week:

Today it is utterly clear in an entirely natural way. It is fast becoming a beautiful sounding amp. Its chief virtues are (1) a s
ense of scale (large), mainly the result of a great, robust bass foundation, reminding me how essential really good bass is in
conveying music realistically; (2) clarity -- especially the definition of individual instruments, partly brought about by an
almost magically silent background; (3) body, which is not the same as bass, giving everything a sense of physical presence;
and (4) beauty, mainly the delicious midrange that JTN and I heard from the BC1022 this past summer.”

“The upper mid and treble range of the O22i has a slight sweetness to it… The midrange flows so smoothly up into the higher
range that you don't notice it at first. It's a purely natural sweetness, not an additive. The result is that peculiar ideal most of
us seek: natural warmth without loss of clarity. The overall effect we feel in listening to music through the O22i is more the
warmth (partly a sense of instrumental body) than the clarity I pointed out; but it is never a warmth that holds things back.”

“In conclusion, I consider the O22i a statement product, the best integrated amp Gilbert Yeung has designed.”

These are some of Bob’s impressions after about a week of listening. It should be noted that with a power supply of this size, it may
take several weeks, or maybe even months, until this amp reaches its full potential.

So we now have two integrated amplifiers in the BC stable that we would consider reference quality: the venerable FtTH2 hybrid
integrated and the pure solid state BC022i. Which one better serves your particular needs and tastes is going to be up to you, but
we are very confident that no matter which one you choose, you will be as pleased with your purchase as we have been in bringing
both of them to market. As always, it is all about the music.
Contact:  bcircle@bluecircle.com  /  519-469-3215
(Optional wood faceplate shown. Standard faceplate is stainless steel.) .