OK, the M-Field. This will probably be long, sorry in advance. For the lazy ones, there should be a TLDR version at the bottom.
I’m around the 30-hour mark, so about 1/3 into the recommended break-in period. But I think I already have a good sense of what I’m dealing with. By the way, I made the mistake of not ordering the Neotech power cable with the amp, I missed it somehow. But I fixed that today by contacting Flux Lab and ordering it separately. If anyone has compared it with a generic one, I’d love to hear your thoughts.
My chain:
HE1000se (neutral/bright-ish but smooth, highly technical) ← M-Field ← SMSL VMV D1SE2 (a mix of neutrality, musicality, and technicality) <- PC with Tidal app.
Non-audio stuff:
- It’s big. And great looking, at least subjectively. There’s lots of empty space inside the chassis, so air circulation must be good.
- There are large uncovered vent holes on the top. Maybe it’s a good idea to cover them with something that won’t affect air circulation?
- It’s really cool for a powerful class A monster. I’m used to the Aune S17 Pro, which easily hits 60°C and more in 100mA mode and high gain with some cables. This is a nice change.
- Mixed feelings about the potentiometer. Feedback to weak, big volume steps. I constantly have to use my DAC's volume control to fine-tune.
Audio stuff:
- It requires break-in. I’ve always been skeptical about this. I never took it seriously when a manufacturer recommended a specific number of hours for burn-in, and I never really noticed any difference - at least when testing headphones. According to Flux Lab:
"It should also be noted that the unit needs to warm up for 100 hours, mainly to burn in the electrolytic capacitors in the power supply. After this, the sound of the amp will be as intended."
In this case, the sound does change. If I didn’t have another amplifier for A/B comparison as a reference, I’d probably think it was just my brain adjusting to the new gear. But I made a long list of tracks with notes on what to pay attention to, just to make sure I wasn’t imagining things. Out of the box, it sounded powerful, but dense, thick, congested, and much less holographic than the Aune S17 Pro. While I loved the overall timbre, I had mixed feelings about the staging, details, nuances, layering, separation, and overall "3D" perception of the soundstage that the S17 provided by comparison. This is why I held off on sharing my impressions for nearly a week.
- Gain levels affect the sound much more than in any other amplifier I’ve used, and this is linked with my previous point. Most of my initial tests were done in low gain because the M-Field has an abundance of power and drives my HEKse on low with plenty of headroom, so for a few days, I didn’t even bother trying higher gains. But when I did switch, the differences were significant and surprising. At higher gains, the sound becomes more dynamic, open, and holographic, but also slightly brighter, less rounded, and more technical. Still, I kept in mind that it might be placebo or inadequate volume matching (though I use my DAC’s volume in 0.5 dB steps to ensure volume matching before any critical listening). So, I emailed Flux Lab to ask an open question about how higher gains affect sound in this amp, or in general. Their response:
"Regarding the sufficiency of the gain, then a lot will depend on the capabilities of the signal source. The higher it is able to provide voltage at its output, the lower the gain can be set on the amplifier. It may well be that you can use an amplifier with a low gain even with demanding headphones, such as Susvara. On the other hand, the gain circuit of the amplifier affects many other processes and affects the depth of feedback. Thus, at the lowest gain you get the lowest distortion, on the other hand - the sound in this mode may become less open and dynamic. In turn, when the gain is increased - the amplifier begins to sound more energetic, fast and open (the downside is that it can begin to sound brighter). Thus, we recommend paying attention to such parameters as openness, energetic sound and balanced tonal balance. Some technical forums recommend using the minimum possible gain to obtain the lowest possible distortion of the audio path. We recommend something else - to select the gain by ear. You can listen for some time in each mode and draw a conclusion for yourself which gain mode you like best. We hope that we helped with your question".
So now that we know I wasn't hallucinating, let's proceed
How does it sound?
Coming from the meaty and dynamic Aune S17 Pro, the M-Field gives me that and more. Aune wowed me from the first listen. I think it's a great contender in its price, can as well be a endgame. I loved its dynamic, muscular, lush sound without losing resolution and technicalities. But simply put, it can’t stand up to the M-Field.
If the S17 Pro is a muscle car, the M-Field is a monster truck - but a monster truck in a suit. It feels like its bigger, stronger, older brother, but also more mature. It engulfs you in music but also separates instruments better. The only edge the S17 Pro might have is in detail retrieval, due to its leaner (and overall flatter) presentation. But the difference was more noticeable at the start, so this might not be the case with time as the M-Field breaks in further.
The bass is a bit more pronounced compared to the S17. Initially, it felt woolly and borderline too thick, but not anymore.
The mids are lush, full, organic, and resolving. Vocals are more centered compared to the S17 Pro, which tends to extend them to the sides.
As for the treble... I'm unable to go into too much detail. All I can say is that it’s not rolled off. Private Investigations by Dire Straits still pierces my brain, as always.
Overall, the M-Field sounds big and authoritative. What’s interesting, though, is that it can sound thick and dense in some tracks, but neutral and technical in others. It can flex its muscles and bare its teeth, but a moment later in a different song, sound natural and “disappear”. The only explanation that comes to mind is that it’s technically capable enough to relay the intent of the sound engineer.
This is why I wouldn’t call it outright warm. I feel it pairs better with neutral and brighter headphones like my HEKse, but I don't think it's reserved for them. In fact, the Aune S17 Pro is softer and more rounded at times, even though it doesn’t sound as rich.
TL;DR:
Great amplifier, lots of power, dynamic, lush, rich, but also clean and technical. Requires a break-in period. Gain levels significantly affect sound - the higher the gain, the cleaner, brighter, and more technical the sound becomes, with more impact.
As I'm eagerly waiting to read your professional take on this monster.
