Pure Audio One solid-state integrated amplifier Review

Saxophone is sumptuous on This is Our Time and I have to note the non-digital presentation here once again. Solid state amplifiers tend to create a sibilance with female vocals that does not occur with the Pure Audio One.

The Pure Audio One demonstrated the ability to present the softness and delicacy of music that is typically the wheelhouse of the Single Ended Triode. No, it is not quite at that level of what I hear from my reference amplifiers (Audio Note M3 Phono Balanced preamp and Empress Silver monoblocks) or the better Single Ended tube amplifiers I have heard over the years. However, the Pure Audio ONE is good enough to be a serious contender with any similarly priced integrated amplifier on sound quality, while offering the audiophile high output power. Remember, this is just referencing music that is in the Single Ended Triode’s wheelhouse.

My Audio Note AN E/SPx AlNiCo loudspeakers are 95dB sensitive and present a generally easy load.  Thus, the Pure Audio One hardly had to work hard to push my loudspeakers. I largely prefer high sensitivity and high efficiency speakers as they allow me to buy amplifiers based on sound quality not sound quantity.  The Pure Audio One gives you both. Playing rock and roll the Pure Audio was superb at offering speed and agility with Guns N’ Roses Use Your Illusion I &II.  Even with some compressed and less than great recordings, the result still offers a big powerhouse sound that will excite rockers aplenty.

The amplifier breezed through the likes of Nightwish, AC/DC, and Dire Straits. None of this was particularly surprising. Higher power solid state generally plays loud with solid bass control. I suppose I am less interested in this aspect of the Pure Audio One as it was to be expected. It was the subtlety and finesse that really impressed me with this amplifier.

By this point, I was curious about the Pure Audio One and sent an e-mail to company co-founder Gary Morrison trying to get an idea as to why this amplifier sounds as good as it does. He replied:

“The entire product is by design. So, for example, the chassis is a good thick gauge of Aluminum (I wanted as little magnetic material as possible). The piece that folds to create the top sides and front is cutout to allow the necessary ventilation. It also reduces panel resonance. The amp is designed to have a long life so we didn’t want the innards to get too hot. Capacitors and wiring are rated for high temperature.

There are two large toroidal transformers and they feed a regulated power supply. Four power supplies in fact, one for each rail of the two channels. The ground design is uniquely free of power supply charging current and this might also help with the quality of sound.

We use the triangular cutouts from the cover as the fins for the heatsink.

All fasteners are stainless steel.

There are no microprocessors or circuits containing clocks inside – less electronic hash and again perhaps a sonic factor.”

Certainly, multiple factors lead to a sum that recreates music in a way that is free from some of the overly analytical presentation found in many audio products.

While I have enjoyed some solid-state amplifiers over the years, such as those from First Watt and Sugden, the Pure Audio One has far higher power and will be able to drive much harder to drive loudspeakers.

Moreover, unlike some amplifiers the Pure Audio One allows for future upgrading by serving as a power amp.  Fortunately, I was provided a Pure Audio Control 1 Preamplifier for testing purposes. The Control 1 preamplifier was subsequently followed by a new preamplifier called — you guessed it — the Control 2 Preamplifier. The Control 2 updates the power supply and uses a more standardized input selector similar to the One.

Regardless, the separate preamplifier makes some significant gains to the overall presentation concerning transparency and overall clarity without taking away the richness of the presentation. I was impressed with the gains made using the Pure Audio Control preamplifiers (although when I pushed the remote control volume, it operated both units at the same time).  Still, I felt the Control preamplifiers open up some of the sound creating more space, air, and articulation to vocals. Put simply, the presentation was more transparent.

Since the One and the Control 2 preamplifier do not offer an on board phono stage, I elected to use my Audio Note M3 Phono Balanced preamplifier for vinyl. The Audio Note M3 is a tube phono stage with dual stepped volume controls for left and right channels. I am pleased to report that the combination was dead quiet and an operational match.

I began with one of my favourite recordings, Butterfly Lovers conducted by Kek-TjiangLim, which I find to be one of the most moving pieces in my collection.

The system was easily capable of reproducing the dramatic dynamic passages while rendering the sweet emotive delicacy in softer violin passages. Delicate, powerful, and altogether right sounding. Percussion was also very well rendered, and almost made me jump out of my chair in the crescendos. Changing over to my Audio Note Empress monoblock amplifiers produced an added sense of ambiance and seemingly richer, fuller decay while maintaining the same speed. A richer tonal balance is somewhat the wheelhouse of SET amplifiers and yet the One acquitted itself remarkably.

Next up was that CD Alive by Hiromi. If you are unfamiliar with Hiromi, she is a gifted jazz pianist who composes her albums. She collaborates with Anthony Jackson on bass and Simon Phillips on percussion. I decided to play her track “Wanderer,” and the M3 with the One in combination was superb at differentiating instruments in space with speed, power, and emotion intact.

Ultimately, the Pure Audio One is one of the greatest integrated amplifiers I have heard. With impressive build quality, aesthetics, and high output power, this is one of the few times I have been excited about the sound quality offered by solid-state amplification. I find most solid-state amplifiers analogous to that of an X-ray that highlights (or overexposes) leading edge attacks and leaves little else. Solid-State Class A amplifiers that I have liked from a few other brands, such as Sugden and First Watt, do not offer the power of the One.  In my view, if you are going to live with a 10-25 watt amplifier it makes more sense to buy a Single Ended Tube amplifier. The advantage Solid-State brings is high power but at the expense of sound quality. The Pure Audio One brings both.

I try to look at products like this and see who might be an ideal match. First, there are people who do not want to deal with the hassle of owning and operating a tube amplifier even though they like the sound of them.  If this is you, this amplifier should top your audition list. Secondly, if you can’t tear yourself away from your 85dB difficult-to-drive loudspeakers even though you like tubes then, again, the Pure Audio One needs to be at the top of your audition list.

While there are a few minor connection quibbles, the sound quality more than makes up for these issues and ultimately the Pure Audio One lives up to the name on the box. The audio is pure in this one; this may be the amplifier you’re looking for.

System used for this Review:

Speakers: Audio Note E/SPx AlNiCo Hemp.

Preamplifiers: Pure Audio Control 1 and Audio Note M3 Phono Balanced.

Amplifiers: Audio Note Empress Silver 8 watt 2a3 Mono-Block amplifiers.

Analog Source: Audio Note TT2 Turntable, Arm 1 (Version 2), and IQ3 Moving Magnet Cartridge

Digital source: Cambridge Audio CXC CD Transport, Audio Note DAC 0.1x.

Cables: Audio Note AN-D copper speaker cables, Audio Note Lexus Copper Interconnects, Audio Note ISIS copper wired modified power bar.

Copy editor: Dan Rubin