Hands On Review: Cyrus Audio Cyrus One


  • Minimalist aesthetics
  • SID automatic speaker impedance matching
  • Home theatre pass-through to turn the integrated amp into a power amp


  • No tone control
  • Sound quality somewhat wanes down at higher volumes
  • No longer as wallet-friendly as the 1984 Cyrus 1

When I lived in Australia, Cyrus was one of my dream brands to own. Cyrus Audio is a well-known British specialist audio company with a solid research and development team leading the charge toward the manufacturing of precision hi-fi equipment. The company is internationally recognized as a leader in audio engineering. So why not buy a Cyrus product, right? Besides, Cyrus was relatively affordable for the student that I was at the time.

But traditionally, budget amplification was considered to have “budget sound.” The appearance and performance of the original Cyrus 1 in 1984 exploded this myth and revolutionized the audio industry. At about half the price of other brands, it demonstrated unequivocally that an audiophile integrated amplifier was well within the grasp of music lovers such as myself, offering the same performance level as equipment from more exotic brands like Perreaux Audio or Plinius from neighbouring New Zealand. This set a new industry benchmark and kicked off an entire generation of Cyrus owners.

Since then, Cyrus Audio has engineered some of the world’s most advanced hi-fi components. The devotion to sonic perfection has made Cyrus one of the industry’s most respected brands. By taking the original concept and bringing it up to date, the 2016 Cyrus One is set to transform the sound of any modern day source, and introduce the Cyrus musical experience to the latest generation of music lovers.

Allow me to start by noting that this is not your father’s Cyrus 1. Other than the name and the attempt to maintain the affordability of the original Cyrus 1, there is hardly anything mirroring the original equipment. Virtually every aspect of this unit is either a step up or a quantum leap from the original.

The Design

I absolutely love the retro-minimalistic design of the Cyrus One. It’s a clear reminder of the original 1984 Cyrus 1, but this time, it’s all black with two relatively gigantic knobs on the faceplate, one for input selection and the other for the volume control. Just like the original, the integrated amplifier is elongated instead of the industry standard 17″ width, which makes it stand out from the crowd.

There are six inputs including a phono input and a Bluetooth input to complete the design with a pair of extremely high quality binding posts that will easily grip 10 AWG speaker wires like the ones I used for this review.


The biggest improvements are found in the amplification section. It now features Cyrus’s own third-generation Class D amplifier, providing 2 x 100W of power with a large toroidal transformer providing a linear power supply throughout for minimal noise separation of different circuits. The amplifier circuit is also equipped with Cyrus’ Speaker Impedance Detection (SID), which will automatically detect the impedance variations of the connected speakers and optimize the amplifier impedance output accordingly through a complex yet sonically transparent digital signal processing algorithm. (More on SID below.)

Other improvements of the Cyrus One include the addition of an aptX-compatible Bluetooth connection, a dedicated high power, high voltage class AB headphone amplifier, MM Phono stage, and four line level inputs. For a dual purpose listening room (two-channel and home theatre), a Home Theatre Bypass (officially called “AV Bypass” by Cyrus) function is included. Once activated, the integrated amplifier will act as a power amplifier for your home theatre needs.


The Cyrus One, when used with my System Audio Aura 30 and Pioneer Elite Andrew Jones towers, drove each speaker configuration to perfection during low to moderately loud listening sessions. Overall speaker performance and sound output fell in line with expectations based on previous experience.
Sound quality was exceptionally clean and well rounded, with a hint of warmth due to my preferred set-up tweak, which consists of the inclusion of tube buffers on my CD player’s analog output.

Since the integrated amplifier is designed for the purist, it essentially runs in “pure direct” mode – there is no tone control. However, I always found my ears wanting to have the bass adjusted to +2 dB and treble adjusted to +2 dB. This is due to the psychoacoustics of human hearing – when we listen to audio at low and moderate levels, our hearing is less sensitive in bass and treble areas. Of course, the decision to alter the bass and treble output was also due to my particular listening space and seating position. Owners of the Cyrus One will need to experiment with their own receiver and speakers to see what best suits their unique environment and preferences.

As noted above, I felt the Cyrus One performed best at low to moderately loud listening levels. Anything above 60% in volume level (best generalized as moderately loud but still nowhere near reference) resulted in some distortion and loss of sound quality. I found that to be surprising, as I also found it held true even when playing songs with virtually no bass energy, such as James Ingram’s rendition of Nat King Cole’s “Unforgettable.” When playing high-energy tunes like Iron Maiden’s “Moonchild” from the album Seventh Son of a Seventh Son, however, at the same volume level, there was no drain-of-energy effect all.

After comparing back and forth between various song styles, I can conclude that the problem may lie with the volume control algorithm instead of the power amplification itself. This deduction was reassured further when I played dynamic soundtracks like the Las Vegas chase scene from Jason Bourne on Blu-ray UHD disc, and the even more dynamic “Pour Some Sugar On Me” track from the Blu-ray Rock of Ages in AV Bypass mode. The distortion and loss of sound quality were not apparent.

Listening to my go-to Chris Botti in Boston (Live) and Madonna Sticky & Sweet Tour concerts in two-channel mode revealed openness and breadth in the sound stage that was surprising coming from something as miniscule as the Cyrus One.

Bottom Line

Would I recommend the new and sonically improved Cyrus One? Absolutely. Since the market is now

much more crowded with offerings than it was back in the ‘80s, the value proposition may not be as enticing as it used to be. But the Cyrus One, at $1,500, is still a compelling offering at a great price.

Why Cyrus One’s SID Is An Important Feature

When you look at the back of your speakers, you’ll see the words “Impedance: 6 Ohms” or something along those lines. However, that’s not the actual impedance of the speakers – that’s only the nominal impedance.

What is nominal impedance? Nominal impedance, in electrical and audio engineering, refers to the approximate designed impedance of an electrical circuit – in this case, the “circuit” is your speaker. The actual impedance may vary considerably from the nominal figure, with changes in frequency. The impedance of a loudspeaker is not constant across all frequencies. Usually, the lower the frequency, the lower the actual impedance and the higher the frequency, the higher the actual impedance. A given audio amplifier may not be capable of driving this low frequency impedance even though it is capable of driving the nominal impedance, a problem that can be solved only by matching the impedance of the speakers with the amplifier.

Unless the amplifier is designed for a particular speaker, there is no easy way to match the impedance between the amplifier and the speaker across the entire frequency spectrum. This is where Cyrus One’s Speaker Impedance Detection (SID) comes in. As soon as you connect a pair of speakers to this amplifier, the SID circuitry assesses the impedance signature throughout the speaker’s frequency range.

By matching the impedance perfectly, the speakers will work more efficiently and there will be less chance of overload. More importantly, the amplifier-speaker combo will yield a much better frequency response, which translates to punchier bass, more detailed midrange, and smoother treble.

Once you’ve listened to SID, there’s no turning back. You’ll be wishing that all amplifiers came equipped with the technology.

This diagram shows the variation in impedance of a typical mid-range loudspeaker. Nominal impedance is usually determined at the lowest point after resonance. However, it is possible for the low-frequency impedance to still be lower than this. Graph Source: Gary Davis, Ralph Jones, The Sound Reinforcement Handbook, Hal Leonard Corporation, 1989


Article Tags:  cyrus audio, cyrus one, kevro, hands-on, review, susilo, hifi, audio, home theatre

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