Cyrus One HD

disclaimer:   I have owned and enjoyed an original Cyrus One in the past so was interested in trying the OneHD when the tour was formed.   I received the Cyrus One HD as part of the review tour and have no financial interest in Cyrus or any of its distributors.   I spent two weeks with the One HD as my daily driver before sending it on to the next reviewer in line and received no compensation of any form for this review.   If you have an interest in the One HD or other Cyrus products, please see their website or their USA distributor AmericaHifi.   Retail price of the Cyrus One HD is $1499.

 

Packaging:

The One HD is a large unit and as such comes packed for travel and not for a retail shelf.  The unit was well packed in form-fitted foam blocks with the manual, driver CD, and power cable all well packed into a separate box in the shipping container to avoid contact with the unit and scratches that might occur as a result.  If purchasing the One HD know that no interconnects are provided with the unit so sets of RCA cables, a USB, optical or coax cable for inputs, and a set of speaker cables will be needed to complete the installation.    The unit does not ship with a remote either, but does have an app available on the Google Play Store and the Apple Store for use with the unit.

 

Build:

Again, this is a fairly plain looking amp.  It is rougly half width and full depth when compared to most full-sized audio components with a well built metal chassis.  The two halves of the chassis are held together by hex-nuts with a pair on the lead edge of the sides that also lock the faceplate into position and a single hex-nut at the rear of each side.   The faceplate lifts out of slots in the metal frame and is connected to the main board by ribbon cable which makes the chassis easy to open for cleaning or should maintenance be required.   The faceplate itself is plastic and high gloss while the remaining shell is powder coated and a more matte satin finish.   There are two large knobs on the front that each have a partial circle of LEDs surrounding them.  The left knob is the selector and the right is volume control.  the power button is tucked beneath the left knob while the headphone jack is at the far right beneath the volume adjustment.   At the rear, speaker binding posts (dual type banana/spade)  occupy both outside edges with power connection and inputs occupying the middle space.     The Unit has USB, coaxial, and optical digital inputs as well as 3 RCA inputs, a MM phono stage input with ground connector, and a single pair of RCA outputs.   The other prominent feature in looking at the unit is a single heavy bolt through the center bottom of the chassis that mounts the monster sized torodial transformer that is the heart of the linear power supply used in the One and One HD.

 

 

 

Internals:

This is the hardest section to write for this unit as the One HD has a lot going on.   It starts with the previously mentioned large toroidal transformer that feeds the power circuitry and feeds everything else hiding inside.   The digital inputs feed a Burr Brown 17xx series dac chip which allows the USB input to handle up to 32 bit data  at up to 192kHz.   The Coaxial and Optical inputs are able to handle up to 24/192 as well.   In addition the OneHD also supports bluetooth input using AptX HD.      Three sets of analog inputs in addition to the Moving Magnet phono stage round out the input options.  Other than an AM/FM tuner, the One HD covers pretty much all the possible bases.    Regardless of which input you choose, they are fed to class D power amplifiers circuits of Cyrus own design if using the speaker outputs or to a class A/B amplifier if using the headphone jack.   The speaker taps also utilize an impedance sensing mechanism.  This can be thought of as a feedback loop where a micro-controller analyzes the high frequency impedance of the connected speaker and adjusts to match the impedance the speaker needs to perform well.   This is one of the things often criticized with class-D amplification, the reconstruction filters in class-D tend to cause impedance mismatches and deviations.     That mismatch is why speakers like my Magnepans recommend against using a class D amplifier to power them.    The One HD although a little light on power at a 100W per channel, can indeed be used safely with the Magnepans and actually drove them a bit better than I expected it would.

Even a computer controlled impedance matching system has its limits though and with speakers generally ranging between 4 and 16 Ohms, its not realistic to expect that same circuit to be optimized for headphone use.  So instead of even trying to tune the class D system to handle 600Ω AKGs, or 300Ω Sennheisers the One HD instead redirects the power to a class A/B headphone amplifier that is more suited to the task at hand.

The One HD also has a mini-USB connector on the rear for servicing or updates so as improvements to the micro-controllers code become available, the One HD can take full advantage rather than becoming obsolete.

 

Controls / Bluetooth:

This is where we part ways with what I thought I knew about the Cryus One HD.  The older model came with a remote that was fairly simple and uncluttered but gave the user quick access to switch sources or adjust volume.    With the One HD gaining Bluetooth input, it makes perfect sense that the remote would be migrated to an app for your smartphone or tablet and that is exactly what has happened.     The App is titled the Cyrus One Remote in the Google  and Apple stores and gives the user the same ability as was found in the earlier generation remote.    The remote is still simple with options to adjust which source is in use,  adjust volume and set maximum volume, adjust balance,  LED brightness, and mute.

I  found pairing the One HD very straight forward and connectivity was quite good once established.   With my LG phone using AptX HD latency was minimal and I only lost connection to the One HD when line of sight was lost and obstacles blocked the signal.    Pairing a new source was equally easy once the connection from the previous source was dropped.

 

Sound:

(Speaker Taps)

Having owned an earlier model Cyrus One, I had some expectations going in as to what I would hear and for the most part I was correct in my assumptions.   The One HD has good resolution and power as long as not matched with something too far outside its comfort zone.  Although I did try it with my Magnepans, I did my critical listening with a pair of Klipsch Heresy IIs that it is more suited to driving.   The One HD has a very clean detailed sound with good texture and enough body to give vocals a natural weight to them.    The nicest thing is the One HD does seem to vanish into the background and picking out any coloration that is contributed to the sound by the amp was difficult.    The other nice feature was the signature does not seem to change appreciably when switching between optical, coaxial, and USB as can sometimes be the case as well.  If there is one knock here, it is that the OneHD does not have the dynamic range that something like my big Levinson can deliver, but remembering the price point of the One HD and the fact that the One HD is also a pre-amp, a dac, and a headphone amp,  this is hardly a stumbling block.

(Headphones)

When switching to the headphone amp, many of those same qualities come through.  Detail is very good with lots of texture and nuance to the sound although there is a touch more coloration here than in the speaker amp.   Here the One HD does show a slight upper-mid lift that translates into female vocals being slightly in front of their male counterparts.    I didn’t find the lift distracting though as it is fairly small and if anything it does make the One HD a better listen for vocal music and choral arrangements as they really stand out nicely.   There is plenty of headroom here and dynamic range so the issue seen on the speaker taps may be more my choice of speaker than anything inherent to the One HD.

 

Interestingly,  The One HD shares the same DAC family with both my Bel Canto DAC in my home system and with the Ifi iDSD Neo that I recently reviewed and still have access to.    Although all three share a dac,  the Bel Canto sounds more analytical and has less coloration than either the One HD or the Neo which both sport a similar lift in the upper mids.     The One HD splits the difference in clarity between the Neo which loses a little detail to musicality and the Bel Canto that is a bit more revealing but also a bit less forgiving.

 

Conclusions:

The Cyrus One HD has to be looked at holistically to be fully appreciated.   The amp alone is quite good, but not quite as good as some at the $1500 price point.  Likewise, the phono stage is good, but can be bettered by other stand alone pre-amps.     The Headphone amp is impressive but again at $1500 is should be fairly good.    When we take all of those things into consideration though, the One HD comes into its own.    None of those devices that I mentioned out-doing the One HD have the feature set to compete with it, and all would require a lot more space and interconnects.   What the One HD brings to the party is a small, all-in-one package that offers solid performance in multiple categories rather than dedicating its efforts to be the best at only part of the equation.    The One HD would make a great office companion or in a den or bedroom where space is limited.    Those looking for a unit that can do it all with a minimum of fuss will be pleased with the One HD’s simplicity.     I could build a better system, but not for the asking price of the One HD, and certainly not with the ease of setup and use of it.  Like I said,  look at the One HD holistically and it can be almost therapeutic.