In 2021 I bought my first Audio Note UK product, the Audio Note M-Zero, which is the entry-level preamplifier from the British company based in Horsham.
Audio Note UK shouldn’t be confused with Japanese Audio Note Kondo, even though it happens occasionally. Generally speaking, having the same for two different companies is not a good thing. The history of the relationship of the two companies could be the topic of a separate blog post, some claim it’s complex, others that it’s a short but painful story.
What remains clear is that Audio Note Kondo was founded by Hiroyasu Kondo in Japan in 1976 – with the launch of what was to become a cult amplifier, the Ongaku, in 1989. According to Audio Note UK’s website, the UK company, founded by Peter Qvortrup, brought its first product, the OTO PP (a push-pull design tube amplifier) in 1991.
From ADL-GT4 to the Audio Note UK M-Zero
I got the M-Zero ex-demo for €600 as an upgrade of my ADL-GT4 that served as both a preamplifier and and USB DAC – after upgrading my speakers, a set of Dansk Audio Teknik Proac clones (of the Super Tablette) to a set of Harbeth M30.1 speakers.
The logic behind getting the M-Zero was 1) a wish to try experiment with a tube-base preamplifier for the first time 2) a conviction that the ADL-GT40 was the weakest link in my setup (the amplifier was a Vincent SP-331, which is a hybrid design using 6N16 pencil tubes for the first stage of amplification that feeds into solid state).
Transformer hum in the Audio Note M-Zero
After a couple of weeks listening to the Audio Note M-Zero preamplifier, I noticed considerable hum from the transformer. I talked to the dealer, and we decided I should drop by for a comparison to another M-Zero that was at display in the shop.
I detected quite a difference in terms of hum in the M-Zero I had bought, and I was offered to change to the other unit, which I gladly accepted, and I was quite satisfied with the upgrade of the preamplifer part of my new setup.
To rule out issues with the interconnects I purchased two sets of AN-C cables – a litz construction with 15 strands of copper and solid RCA connectors.
My next Audio Note product was a DAC 0.1X, also bought ex-demo – in terms of sonic signature this was quite a step up in sound compared to the ADL-GT40, which should be expected.
Second M-Zero sent for repair
About a month of having owned the M-Zero one channel gradually lost volume – and noise appeared. Once again I packaged the preamplfier and went to the dealer’s shop. The problem as diagnosed as a faulty tube and the unit was sent for repair, as the 6111 tube is soldered to the circuit board meaning it cannot be replaced in an easy manner by the layman.
I considered transitioning away from the brand at this time, but liked the sound and new to tube amplification concluded that this kind of instability was to be expected. Being very satisfied with the DAC 0.1x, I decided to exchange the M-Zero for an M1.
This setup sounded very good for about half a year.
Fixed 6111WA Tube in the DAC 01.X
The upgrade from M-Zero to M1 allowed me to experiment with different tubes, which wasn’t possible, as previously mentioned, with the Audio Note M-Zero because its 6111WA tube is soldered in place (for inexplicable reasons, I think that a tube socket wouldn’t cost a fortune in either purchase price or installation). The same applied to the 6111WA tube in my Audio Note DAC 0.1X, which I never experienced any issues with.
NOS Tubes from EI Yugoslavia in Audio Note M1
The Audio Note M1 preamplifier came with an Ei Yugoslavia ECC82 tube installed, which, as far as I could gather, is sonically similar to Telefunken tubes; and some sources mentioned that the Yugoslavia tubes were made on old Telefunken machinery.
Transitioning away From Audio Note UK
I decided to swap in the M1 at a fair price in exchange for a P2SE power amplifier, which also functions as an integrated amplifier if you only use the one line level input. Supply chains were under pressure, but the amplifier was delivered rather fast. It was the wrong model, though, a P2, not a P2SE (‘SE’ standing for ‘single-ended’). According to the dealer this happened twice.
Significant hum in the Audio Note P2SE
The Audio Note P2SE suffered from a heavy hum from the transformers which could be heard at 2–3 meters distance and remained audible when listening to music at the levels I normal listen at.
In addition, the volume levels were audibly and measurably different in the right and left channel.
Lastly, the general sound was thing, bass-lean and somewhat unfocused. Similar reports from others made me want to move away from the Audio Note product line.
Comparison with a Harmon Hardon amplifier
I bought a cheap Harman Kardon integrated amplifier (with built-in RIAA) along with a professional-grade sound card to rule out other issues in my setup. I even went as far as to get a hearing test to rule out problems with my hearing, which was above average for both ears for someone my age.
It might have been mishandled during shipping – it came single-boxed in rather thin cardboard internally braced with foam. At this price level (€3,950), I would have expected double-boxed). No signs of damage neither outside on the box or inside on the amplifier itself were visible.
Audio Note P2SE > Sugden A21SE Signature > Leben CS-600
The Audio Note P2SE was returned without any issues and, by my wish, exchanged for a Sugden A21SE Signature, which I was pleased with – it sounded beautifully, fluid, transparent and well-paced out of the box with no hum, no volume differences – a solid performance, which brought back the focus on music – instead of a constant fear of equipment that does not sound.
However, the world of tubes beckoned, and after a lot of research I got an integrated Leben CS-600, which is dead silent; and volume levels are perfectly equal across the right and left channel by both measurements and in a subjective listening experience.