August 2023

World Premiere Review!
Audio Note UK M2 Linestage / Preamplifier And Conqueror Power Amplifier Review
Taking the road less traveled.
Review By Paul Schumann

  Hi-fi audio emerged in the 1950s with the introduction of the LP record. As the business evolved and stereo became the norm, acoustic suspension speakers gained popularity due to their smaller footprint in the family room. What followed after that can be called an arms race between audio manufacturers to build more powerful amplifiers. This continued as hi-fi became high-end audio. It was not uncommon to see on the pages of print magazines reviewing amplifiers rated at 400 Watts per channel or more.

But not all music lovers were following this path. While the audio business was trending towards the more powerful tube and solid-state amps, an underground movement in Japan was extolling the virtues of the old low-powered Western Electric amps when paired with speakers of the same vintage. This movement slowly spread across the globe. Out of this movement, Audio Note (UK) was born in 1991.

If you are a long-time reader of Enjoy the Music.com, you are already familiar with Audio Note UK. Albert Einstein once wrote, "Everything should be made as simple as possible, but not simpler". This basic idea guided Peter Qvortrup and Andy Grove on their journey.  As a reader of Sound Practices back in the day, I always considered Audio Note equipment as top-of-the-mountain stuff. Unfortunately, by the time I had gotten hip to the low-power audio revolution, I had already invested a significant sum of money in a pair of hard-to-drive speakers. Due to financial circumstances, I ended up using them for several years.

Since I built my Super Pensil 12.2p speakers three years ago, I've been ready to listen to SET low-powered amps. Now and then I go to the Audio Note UK site to see what is up. Over several visits, I became fixated on the Conqueror amp. It looked to be a good fit for my system. Finally, I perused the internet, and to my shock, I couldn't find a formal review. I asked Enjoy the Music.com's Creative Director, Steven R. Rochlin, if he was interested. Before I knew it, I was trading e-mails with Peter Qvortrup! For my review, Audio Note UK would build a new amplifier. This is because each Conqueror amplifier is hand-built to order for the customer. So, in the meantime, I had to sit and wait. To be honest, I was not patient about it.

Let's Talk About The Conqueror Tube Amp
The Audio Note UK Conqueror stereo power amplifier is a pure Class A single-ended (SET) valve amplifier that uses the highly regarded 300B direct heated triode valve. This amp meets what Audio Note calls Level 3 Criteria: Pure Class A operation, Zero Negative Feedback, Single Ended Output Stage, Valve Rectification, Directly Heated Triode operation, and high-quality materials and component quality. All of these criteria are part of the basic tenets of Audio Note UK design. Why is this a road less traveled? Because it's hard to do. It would be easier to slip a little negative feedback in there to lower the THD and increase the damping. So what if the amp dips into Class B? You won't need as robust a power supply. I could go on. Audio Note is intentional about every aspect of the build and materials in their equipment. This all adds up to the Audio Note UK sound. This is the road less traveled.

As I said, I had to wait for my review amp because it was made to order. The model I received was what could be considered the Conquer base model. This model utilizes two 6SN7s for the driver tubes and standard Audio Note UK output transformers. A Low-Gain version is also available that utilizes 6J5 driver tubes instead. There are two additional upgrades Audio Note provides: Silver and Silver Signature. The Silver edition includes Audio Note UK Tantalum film resistors, Audio Note Copper Foil signal capacitors, and IHiB C-core output transformers.

The Silver Signature is an additional upgrade with the inclusion of Audio Note IHiB Double C-core output transformers. Naturally, you get a choice of anodized aluminum or black acrylic for the fascia and anodized aluminum of black anodized aluminum for the top plate. All of these choices are part of the Audio Note UK way.

After weeks of anticipation, the Conqueror arrived. I eagerly put it in my system to discover that the marriage between my KORG B1 Preamp and the Conqueror was not a happy one. With no signal going through the system, I was hearing a lot of hiss. In addition, the KORG B1 was very microphonic. I tried all sorts of different combinations of interconnects, power cords, and ground arrangements, but the hiss persisted. Peter had cautioned me that preamp compatibility might be an issue with the Conqueror, so I reached out to Adrian Ford-Crush of Audio Note UK to apprise him of the situation. Without a blink of an eye, he told me they'd make me an M2 Line Stage preamp. I was on the road less traveled, and it had a few more twists than I had expected.

Let's Talk About The M2 Linestage
The M2 Line Pre Amplifier meets Audio Note UK Level 2 Criteria. It's not Level 3 like the Conqueror because it doesn't employ a direct-heated triode, which is typical for a preamp. The M2 Line Pre Amplifier features a 6SN7 line stage and a valve-rectified power supply incorporating a 6X5 and an ECL82. Like the Conqueror, there are several versions available. Other options include balanced versions and one with built-in phono stages.

The M2 Line accepts four inputs and has two outputs. On the front, there is a corresponding rotary switch and a volume control. This being an Audio Note UK product, there are things incorporated that surprised me. There are connections and a switch for a tape loop, and balance control. I have to be honest. I don't know when I last saw those two features on a high-end product. Lastly, the M2 Line has two feedback switches in the back to control its output. Once again, the road less traveled had a few more surprises.

After waiting on pins and needles, the M2 Line preamplifier arrived. I eagerly installed the M2 in my system. With the feedback switches set in their "feedback-off" position, the hiss was still quite noticeable. I switched them to the "feedback-on" position. The hiss was reduced, but still at a distracting level.

I shared this with Adrian and he reminded me that they had included an attenuation kit to lower the input impedance of the Conqueror if noise was still a problem. If found the zip-lock baggie with four Audio Note UK Tantalum resistors, then turned and stared at the Conqueror. At this point, I felt the road had narrowed to a footpath.

Have you ever modified a $6600 amp that doesn't belong to you? Neither had I. With some trepidation, I got out my Allen wrench set, removed the top cover, and started to poke around. The Conqueror is a beautifully built amplifier. The signal path is all point-to-point wired, the circuit board is a thick piece of FR4 (a flame-retardant epoxy resin and glass-fabric composite), and all exposed leads are covered in Teflon tubing. After staring a bit more at the beautiful amp, I carefully proceeded to remove the 220 kOhm grid resistors and replace them with 33 kOhm and 68 kOhm resistors. I did burn myself one-time soldering, but I got the job done. I checked the new connections with my multimeter.

Satisfied with my work, I put the cover back on and installed the Conqueror back in my system.

Time For Joyful Music
Nervously, I turned everything on and listened. Joyfully, I observed the hiss was practically gone. I could hear it only when I put my ear right up to the speaker cone. I then started playing some music, but I noticed a slight edge to the music that wasn't present before. I sat there puzzled until I remembered I still had the M2 output switched to "feedback on". Once I switched the feedback off, everything sounded much better. Now I was ready to do some earnest listening. I was starting to get the hang of this less-worn path!

After some break-in, I decided to give the M2-Conqueror duo a serious spin. I put on my triple album, Radiohead's Kid A Mnesia. I've listened to both of these albums quite a bit, but listening to them on vinyl with the Audio Note UK gear was a mind-bender. Kid A and Amnesiac were probably two of the band's most experimental albums with loads of altered sounds. While listening to these tracks, I had the strange feeling of listening to something familiar, yet entirely new. I felt like Thom, Jonny, Colin, Ed, and Phillip had laid down those tracks just for me. How could this be happening? I realized the path I was on was allowing me to experience the forest in a new way.

Eagerly, I dropped my Ansermet Stravinsky Symphonies platter on the turntable and started listening to Igor's Symphony in Three Movements. This album was recorded in 1960 and has always struck me for its clarity. As soon as I lowered the needle and sat back down, I had the same experience as with Radiohead. I knew this recording quite well, yet in many ways, I felt like I was hearing it for the first time. What I was hearing wasn't more detailed, it was more intimate. I could feel all the preparation of the L'Orchestre De La Suisse Romande leading up to the recording. I could sense Ernest Ansermet guiding his orchestra through the tricky passages. I could perceive the space of Victoria Hall around me.

Now the path was almost totally gone, but I wasn't concerned. I just stepped over any fallen logs and gently pushed the small branches out of the way. Small birds flitted in the underbrush and ferns brushed my calves as I walked on. I was no longer traveling through the woods, I was communing with it.

Feeling more adventurous, I got out my recently purchased album of Egberto Gismonti's Dança Das Cabeças. This collaboration between Gismonti and percussionist Nana Vasconcelos is a brilliant melange of musical styles reflecting their Brazilian roots. Already a fascinating recording, listening to it through the M2-Conqueror combo was utterly engrossing. Every note, every noise, every percussive stroke had meaning. Now I was in the deepest of old-growth forest, standing still, staring up at the canopy, the dappled sunlight on my face. All I could hear was the wind rustling through the trees. I was now one with the woods.

The Finale
As I continued to listen to music with the Audio Note UK M2 linestage and Conqueror stereo amplifier pairing, this intimate experience prevailed, no matter the recording or the medium. Before I knew it, there were stacks of records and CDs in my living room because I was too eager to grab a new album before putting the old one away. My listening sessions had become tranquil meditative experiences. Now I was sitting in a Sukhasana pose on the forest floor. The woodland creatures moved past me, unconcerned with my presence. Shure, I had to continue along the path at some point, but at that moment, I was happy where I was.

I don't know how much of a Music lover Robert Frost was. Heck, I'm not sure I truly understand "The Road Not Taken". I do know that my exploration of high-end audio has been a very interesting journey. I've been really lucky to meet people, in person and online, who have been kind with their time and helped me find what I was looking for. Is my journey over? Not by a long shot. Right now, I just want to thank all of the good people of Audio Note UK who have been kind enough to fulfill a long-time dream and allow me to listen to their equipment in my home. My time in the woods will come to an end soon. I just need to enjoy it before I have to move on.

Specifications
Type: Vacuum tube stereo linestage and amplifier
Conqueror Vacuum Tube Power Amplifier
Type: Power Amplifier
Input Impedance: 100 KOhm, line level
Input Sensitivity: 250mV for full output
Maximum Output: 8 Watts RMS per channel into 4 or 8 Ohm loads
Valve / Tube Compliment: Two 6SN7 (or) two 6J5 (Low Gain), two 300B, and one 5U4G
Weight: 20 kgs.
Dimensions:: 195 x 205 x 500mm (HxWxD)
Price: $6599

M2 Line Preamplifier
Type: Lie-Level Preamplifier
Input Impedance: 100 kOhms
Input Sensitivity: 126mV for 1V Output
Output Impedance: <10 Ohms
Weight: 7 kgs. 
Dimensions: 140 x 295 x 450mm (HxWxD) 
Price: $4677

Company Information
Audio Note (UK) Ltd.
Viscount House
Units C, D & E, Star Road,
Star Trading Estate
Partridge Green
West Sussex RH13 8RA
United Kingdom

Voice: +44 (0) 1273 830800
E-mail: adrian.ford-crush@audionote.co.uk 
Website: AudioNote.co.uk