Musical Fidelity M6sDAC Digital To Analogue Converter Reviewed

Musical Fidelity were one of the pioneers of the external digital to analogue converter, bringing their first to market in 1987 when CD was still in its infancy and the number of outboard DACs on the market could be counted on just one hand. The M6sDAC is their latest flagship model reintroduced following the sale of Musical Fidelity to Audio Tuning GMBH.

The M6sDAC is a feature-packed unit with three coaxial, three optical and a USB input, the latter supporting 32-Bit, 768kHz audio and DSD 64/128. The high rate of upsampling aims to move any digital artefacts to well outside the audio band, allowing their removal by filters without detriment to the uppermost reaches of the audio band. PCM signals can be handled up to 32-bit/ 384kHz and DSD up to DSD128. Its optical and coaxial inputs handle 24-bit, 192kHz high-resolution audio. The unit has both single-ended and balanced outputs and a quality headphone amplifier with a quarter-inch (6.3 mm) output jack on the front.

M6sdac Front Black

Furthermore, the M6sDAC can act as a digital preamplifier, with its volume controlled either via the front panel or the included remote. A switch on the rear toggles between variable and fixed output modes, though connecting a pair of headphones will mute the outputs and enable the volume control regardless of the output setting.

Musical fidelity are keen to stress the DACs technical capabilities, as with all of their products. Distortion at 20kHz is a claimed 0.0004%, with stereo separation better than 120dB, linearity better than 110dB and signal to noise ratio better than 119dB. Total correlated jitter is less than 12 picoseconds peak to peak, with linearity <±0.1dB down to -96dB. The DAC section incorporates the ESS Sabre ES9028PRO in a fully differential circuit. These chips are capable of handling up to eight channels of 32-bit, 768kHz audio and feature Hyperstream II technology with high dynamic range, exceptional signal to noise ratio and vanishingly low distortion. Interested readers can view technical information for the ES9028 Here.

Many manufacturers opt for the newer ES9038 Pro chip in their latest devices, though devices based on that chip are known to present higher levels of jitter than the proceeding ES9028. Of the filters available within the ES928 chip, Musical Fidelity have chosen a minimal phase filter with fast decay, which is not switchable by the end-user. Measured frequency response is flat to within 0.1dB throughout the audio band (20Hz – 20kHz), and a roll-off of just -0.4dB out to 45kHz and -2.4dB out to 90kHz. These measurements are outstanding by any standard.

The headphone amplifier is quite capable of driving high impedance headphones and is far more than the afterthought found in most source components. The discrete amplifier can output 1.5W per channel into a 32-ohm load. THD is less than 0.0012% (20Hz – 20kHz) with an A-Weighted signal to noise ratio of better than 115dB. Output impedance is 40Ω, and it will drive headphones between 10 and 600Ω with ease.

Clearly unboxing is a big part of the first impression Musical Fidelity hope to impart on the buyer. The unit is double-boxed, held securely within foam blocks and wrapped in a drawstring bag of thick cloth. Cotton gloves are provided, as is an instruction manual, IEC power cable and remote control. Everything is beautifully presented, right down to the manual itself which is spiral-bound with glossy covers.

The unit is smartly finished in typical Musical Fidelity casework, with thick wrap-around steel panels and a chunky aluminium fascia on which are a neat row of small metal buttons, a remote sensor, headphone jack and a machined aluminium volume knob. The volume knob fronts a digital encoder which rotates with small detents, and the controls themselves appear to be of excellent quality.

M6sdac Rear Black

Around back are three coaxial and three optical jacks, along with a micro USB input. This is an interesting decision with no obvious purpose besides being slightly more inconvenient than the more standardised USB B jack as used in 99% of DACs. You do get an adapter in the box, however. Next to this is the output mode switch, balanced and single-ended outputs and an IEC power inlet. The jacks are standard issue and not the chunky jacks as found on the M6sVINYL which is a curious decision and presumably one limited by cost, though they’re of perfectly acceptable quality so no cause for complaint here.

The user interface consists of a selection of miniature LEDs indicating the chosen input, resolution and status of the upsampling circuit, which is not switchable and thus remains permanently active. The three front-panel buttons control power and input selection, which is the full extent of available end-user configurability. Filter switching would have been a welcome addition, as perhaps would a facility to disable the upsampling or an individual button to access each input.

The remote is the same lightweight plasticky unit as supplied with most Musical Fidelity components. An array of controls are specific to the DAC including input and the aforementioned volume, which is independent of the control for an amplifier or preamplifier for which buttons are also provided. The remote will also operate many components in the Musical Fidelity range, and due to its use of standardised RC5 coding will operate kit from many other brands too.

Sonics are best described as dynamic, expressive and often-times dramatic though with plenty of finesse when required. Stereo imaging is nothing short of holographic, with such pin-point presence as to make the sense of realism so palpable, the feeling of ‘being there’ so real. It’s enthralling, captivating, exciting and stirring all at once. Dynamics are handled with veritable ease, further adding to what is a performance that is, above all else, musical.

Yet despite all this, the overriding impression of the M6sDAC is that its sound is just ‘right’. Nothing is added, nothing is taken away. This is music at its best, able to uplift or emote. There’s no audio trickery going on here. This is digital audio reproduction at its best; nothing more, nothing less. This is not audio magic, I realised as I listened further. It’s simply the best representation of the digital audio signal. What comes out is what goes in, just superior due to the conversion, filtering and upsampling.

The M6sDAC is frankly astounding. So much is made of high-end digital requiring advanced clocking, hyper-accurate digital circuitry, advanced computing algorithms and the most interference-free power supplies. There are many products on the market at stratospheric prices which take the same zeros and ones, ad a sprinkling of magic audiophile dust and claim to deliver results that set new standards in digital audio reproduction. It’s funny how few of these can back up their claims with measurements, which, especially where digital audio is concerned, are a perfectly plausible way to assess a DACs performance.

M6sdac Front Silver

What you actually need is a thoughtfully designed digital converter with a well-designed output stage and refined, quality power supply electronics. There’s no audiophile magic here, just a thoughtfully designed and beautifully built digital converter with exceptional measurements, able to lay claim to equally exceptional performance. The M6sDAC is quite capable of demonstrating what digital audio has to offer. Highly recommended.

By Ashley

I founded Audio Appraisal a few years ago and continue to regularly update it with fresh content. An avid vinyl collector and coffee addict, I can often be found at a workbench tinkering with a faulty electronic device, tweaking a turntable to extract the last bit of detail from those tiny grooves in the plastic stuff, or relaxing in front of the hi-fi with a good album. A musician, occasional producer and sound engineer, other hobbies include software programming, web development, long walks and occasional DIY. Follow @ashleycox2


  1. Thanos you for this review clarifying that value-for-money can be found in the DAC space.

    Let me suggest one point of clarification : it would appear from pictures that the M6s does not have four 9028 chips, but only one. Rather it seems that each channel uses four of the chops’s 8 channels.

  2. HI, have you noticed the dac changing inputs by itself for no apparent reason? It often happens to me that the input is switched from coaxial or optical to usb while listening to music. This is weird and very irritating.

    1. No this has not happened to me at all. Try covering the remote sensor, it may be that your remote is false triggering and needs to be replaced, or it could be that you have another remote in the system that is conflicting. Otherwise you’ll need to get the DAC serviced.

      1. This happens without anyone touching any remote. Do you think that the remote might be firing by itself? Can this happen? I will take the batteries off the remote for a while and see if the problem continues. Trouble is it is not predictable when this happens. I am suspecting also interference from mobile devices, Bluetooth or whatever but this would suggest a problem with the device.

        1. A faulty remote can fire by itself, or remotes for other devices can conflict if they share the same infrared codes. It’s unlikely, but a piece of black tape over the infrared sensor on the front of the DAC is the easiest way to tell. Check your connections are secure (the USB connection in particular). It certainly shouldn’t conflict with mobile devices, I have several devices in close proximity to mine with no issue and the frequency bands are totally different anyway.

          1. I am now testing having removed the batteries from the remote. I also noticed one other thing and would be obliged if you confirm whether your dac does the same or not. If I remove the usb plug the green upsampling led stays on, so it looks the dac is still locked on to something. Very weird. I even tried switching the dac off and on from the mains and the green led comes on again when usb input was selected. I am trying to establish if my sample has abnormal behaviour relative to other samples so I can document the problem when I bring the dac back to my dealer. Thankfully it is still under warranty.

              1. Ιt only stays one on usb input, when there is no signal coming through. It does not light on the other inputs. This is the third MF dac I have had and this behaviour is unique.

                1. When the light is on do you have the USB cable disconnected? If it is still connected the light will stay on as there is still data passing through the USB input even when there’s no music playing.

          2. I wanted to thank you for your suggestion that the remote might have been the culprit because the problem has not recurred since I disabled the remote almost 3 days ago. I will ask for a replacement through my dealer. Thank you again, I would never have thought about the remote misbehaving like this.

          1. Hi since my comments in here I have pinpointed the problem. The M6sDAC switches randomly and unexpectedly from other inputs to usb input WHEN USED WITH THE VARIABLE OUTPUT function enabled. Obviously a glitch.

            1. Interesting. I have not seen this behaviour myself. I would suggest having your local Musical Fidelity service agent (Henley Audio in the UK) have it in for a service and a firmware update.

  3. In my opinion reviews should always include MSRP and distributor/company contact info. Is there a reason this is omitted?

    1. I don’t include them as these reviews have a strong worldwide audience. I also don’t recommend any one dealer. Long-time audiophiles will likely have a preferred retailer already, and more general consumers will probably research online to seek out the best price. Henley Audio is the UK distributor with a product MSRP for the M6sDAC of £1399.

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