The M-FIELD model uses MOSFET transistors in the output stage and has a unique sound signature and tuning. The sound is characterized by a darker tone and a thicker, fuller sound in the low-frequency range. The sound has a smoothness, a certain intimacy that is characteristic of MOSFET-based devices, with an impressive volume of soundstage.
Mono Input and Sync Module
We have developed a scheme for the most demanding listeners to synchronize the two amplifier units. This allows for an even greater power reserve, resulting in a previously unattainable listening experience.
Each channel of the amplifier operates in a fully balanced mode. You simply select which unit is the primary and which is the secondary.
This will synchronize the volume levels of the two units. The synchronization system also allows you to control the operation of the second amplifier, so that when the primary unit is switched on, the second unit is automatically switched on.
Power Supply
The power supply uses a power transformer specially designed for this amplifier model, which has separate windings for powering the right and left channels. The power supply also uses four high-capacity capacitors produced by Cornell Dubilier, which can provide dynamic and detailed sound.
The power transformer has a very low dissipation field and noise. This permits the amplifier circuit to function without any apparent hum, even when using high-sensitivity headphones.
We have also used an Ultra Pure Oxygen Free Copper (UP-OFC) power cable from Neotech from the AC Inlet socket to the power transformers. This has allowed us to achieve a more focused sound in the low-frequency range and more punch in the mid/high range. You will get the most out of this unit if you use a good-quality power cable, but you can be sure that you already have a great basis!
Amplifier Part
The output stage operates in class A, which allows transmitting signals of small amplitude with the highest accuracy. The amplifier circuitry uses J-Fet transistors at the input and MOSFET transistors at the output. The power supply for the amplifier circuitry is 70 volts to ensure uncompromising dynamic performance with the most demanding headphones on the market.
By refining the heat sink design, the amplifier circuitry is promptly prepared for utilization, and subsequently shares in its greatest sound quality only after a mere 15 minutes. In addition, we have partially placed the heat sink under some of the PCB components, which allows the amplifier circuitry to start up faster and provides better thermal stability for the entire circuitry.
We use Ohno monocrystalline copper (UP-OCC) cable at the output. This allows the amplifier’s circuitry to unfold to its full potential – the mid-range comes into full color and no detail is hidden from the listener’s ears.
To achieve a balanced and refined sound, the amplifier has been carefully selected from a wide range of components. Components used in the circuits include Takman resistors (Rex series), PRP resistors, Cornell Dubilier, Nichicon, Wima, and Epcos capacitors.
Volume control
The volume control is based on a relay attenuator and contains 64 steps. The control circuit uses Panasonic fast signal relays with low contact resistance. The analog signal is fed to the relay attenuator located next to the input sockets, and the ALPS variable potentiometer (Blue Velvet series) is used for control only.
This arrangement allows the classic potentiometer to be used for volume control, with the analog signal going to a relay control located next to the input jacks. This allows for high sonic transparency even at low volumes.
In this amplifier model, we have enhanced the volume control program for better system response and improved overall usability. This volume control eliminates the problem of volume imbalance between channels and enables you to finely tune the level even on high-sensitive headphones.
Aluminum RC
Optionally we offer a volume remote control with a laconic and austere design. The unit is CNC-machined from top-quality aluminum to guarantee its strength and durability.
The remote is coated in a black anodized finish, imparting a stylish appearance while shielding it from abrasions. The buttons have a distinct, effortless movement and are tactually distinguishable. Our accessory guarantees reliability and functionality, making it a delightful supplement to your amplifier.
Neotech UP-OFC Power Cable
In the discerning world of high-fidelity audio, every component, including often-overlooked power cables, plays a crucial role in shaping the overall sound quality. Drawing upon extensive experience in crafting high-end audio systems, we’ve selected a meticulously optimized solution at an exceptionally reasonable value. We want to share high-quality power cable which enhances audio quality by expanding dynamic range, with improved resolution, and offers a noticeable and rewarding addition to your desktop system.
Our power cable based on an NEP-5002 conductor from Neotech, delivers outstanding value for money. Its construction features thick conductors (0.42mm) of ultra-pure oxygen-free copper (UP-OFC), ensuring exceptional dynamics and resolution. The ground conductor’s smaller cross-section (1.43mm2) results in a slim and flexible cable for a better user experience.
The cable provides complete protection from external electromagnetic radiation, thanks to an internal aluminum foil shield and a drain wire. Filling the free volume with synthetic fiber ensures comfortable flexibility and a “memory” effect, allowing the cable to be easily positioned and maintained in the desired position.
Each cable is hand-crafted in our workshop and equipped with high-quality VIBORG or TTAF connectors with gold-plated copper contact groups. The cable is supplied in a length of 1.8 meters (6 feet). We are striving to enhance your audio experience and unlock the true potential of your sound system.
Neotech UP-OCC Headphones Adapter
For a fully balanced connection between headphones and two devices using a conventional balanced XLR 4-pin cable, we offer a high-quality DUAL 3-pin male to 4-pin XLR female adapter cable.
It is designed with four separate wires, each made up of Neotech UP-OCC multi-strand cable produced from Ohno cryo-treated monocrystalline copper. The wire gauge is 22 AWG (one wire comprises 115 cores with an overall cross-section of 0.33 mm2). Each cable is meticulously crafted in our workshop and fitted with connectors supplied by Neutrik, a world-renowned leader in high-quality connectors with a reputation for exceptional reliability. The cable comes in a length of 1.1 meters (3.6 feet).
Robert Brown (verified owner) –
I’ve had the M field stack for about 4 days now and am close to 96 hours of burn in time at the moment. Right out of the box it wasn’t perfect but what really struck me was how open sounding my headphones were, Hifiman HE6 SE V3’s, like I was finally hearing some real sound staging and space in the music.. I’ve been through many amps with these phones and never heard anything take hold of them like this. For the first time it sounded like I had all the power these headphones will ever need. Everything is clear. You can follow whatever instruments or effects you want in your music or just be engulfed by all of it if that’s how you like to listen. Treble has a unique quality of being very clear to me at least without ever feeling like it was to much. The bass is very enjoyable. Always there but never over powering even if it is using mosfet transistors. By the 50 hour mark this was sounding absolutely fabulous and I was hooked listening nearly all day at that mark. These amps have pretty much blown my expectations out of the water and I think these will sound great with just about anything you throw at them. They will always have enough power. Best headphone amp purchase I’ve ever made and will allow me to start pairing down my collection. If you buy these you will not regret it. Hats off to Flux! Cheers!
gsleite1 –
The M-Field stack. You’re considering it because you have low-sensitivity headphones or low resistance to the two-is-better-than-one impulse.
I’ve used both the single M-Field and the stack (acquired my pair in separate arrivals about a month apart) and, yes, adding the second M-Field is worth it, and especially if you have a hard-to-drive set of cans like the ones I’ve primarily used with my Flux amps, an original Hifiman HE-6.
One M-Field? It’s exactly as Flux Lab describes, a warm MOSFET sound but not lacking in technicalities. The highs are presented in detail, just not shrill. Lows? Warm sub bass, not at all digital sounding, like the sound of standing a few rows back from the stage at a small outdoor R&B concert.
And the mids? This amplifier is mid-forward, no doubt, and this aspect of its sound reproduction becomes more or less apparent depending on the recording. It’s very mix-dependent, I’ve found, on whether the singer or principal horn player takes a few steps forward as the bass drops 10 feet back. On many recordings the playback does not appreciably change this layering.
All this applies to the single M-Field, and some of these colorations differ slightly depending on the gain setting you choose.
With the stack every positive aspect above is magnified. The MOSFET liquidity stays but the treble gets a bit of a polish. The lows? Even more full, more of that upright bass in the background coming forward just a few steps. Midrange remains a standout, somehow sounding more defined without being more forward.
A caveat: (Burn-in skeptics should skip this paragraph.) My experience shows the sound of these amps definitely benefits from prolonged use of a few dozen hours. Flux’s recommendation there is not at all snake oil. This is especially noticeable in the bass, which — I know this is a cliché — really tightened up after a few weeks.
If you’re considering this stack or even a single M-Field don’t hesitate. The sound is unique — in a good way — among my modest collection of headphones amplifiers, and if you’re wondering what you could do to put a very engaging sound in your chain this incredible value of an amplifier is where you should look.
molsen81 (verified owner) –
I push my headphones to the max and prefer music at high volume. When choosing the M-Field, there was no question that I was opting for the balanced stack. The open space sound is very impressive and this amp really enhances planar magnetic headphones. Hifiman models such as the Isvarna and Ananda Unveiled have been spectacular examples but I soon plan to try the Double Sided Modhouse Tungsten also. This amp gets my approval and the tube-like sound is a plus.