Sonic Compass · Mojo Review · DAC/Amp · Session Review
Muse HiFi M3 Ultra
The first tube dongle at about US$100: warm, airy and velvet-smooth, tubes only, with nothing to switch.
A pure-tube dongle for tube lovers: warm, smooth and airy, with real power, little heat, no RF noise and over 12 hours of battery from a phone. The trade is a slower, more coloured presentation and no solid-state mode.
- Real vacuum tubes at about US$100
- Airy, wide and open stage
- Velvet-smooth treble
- Runs cool: about 33C after 4-5 hours
- Over 12 hours of battery from a phone
Where it sits
Sonic Compass does not score gear out of ten. Gear and listeners are plotted on the same seven axes, so a review tells you where a product sits — and you can see how far that is from where you sit. A position is a description, not a grade.
- Tone ColourVery warm · 80%
- Texture DetailDetailed · 70%
- Dynamics JumpPunchy · 68%
- Space & ImagingVery spacious · 85%
- Timing & FlowBalanced · 55%
- Comfort & FatigueVery easy-going · 90%
- Emotional EngagementVery immersive · 85%
Warm, organic and slightly coloured. High = warm on this scale.
Ample resolution with the CJ20, a touch slower and smoother than a delta-sigma DAC and amp.
Punchy with authority and a bit of speed, but not super fast. Full-bodied and engulfing.
Airy, wide and open. The quality Andy says he loves most.
Transients are slower and smoother than a pure delta-sigma design.
Super-smooth treble, runs cool at about 33C after 4 to 5 hours, no RF interference.
Immersive and musical, with intimate, frontal mids and vocals.
The Muse HiFi M3 Ultra is a pocket USB DAC/amp built around two real JAN6418 vacuum tubes and an ES9028Q2M DAC. Andy first met it at CanJam Singapore, where Muse HiFi told him the price, and calls it the first tube dongle priced at around US$100. He compares it with the iBasso Nunchaku, the Beta XI2 and the Cayin RU6, which he says cost over US$200 and up to almost US$500.
He drives it from an iPhone 17 Pro and a Xiaomi Mi 9T, mainly into his AAV CJ20 planar IEM and, from the 4.4mm balanced output, a FiiO FT7 headphone.
Listening journey
Overall — Warm and very musical. Against the Nunchaku, the UA7, the Beta XI2 and other dongles, Andy finds those more analytical and technical, where the M3 Ultra leans musical. He says that does not make it less resolving: with the CJ20 he hears ample resolution, imaging and detail. His key word is airy: wide, open, organic, analog and natural, with some warm colour.
Treble — Super smooth, with a sparkle and a decay he calls very silky. Transients are a bit slower than a pure delta-sigma DAC and amp. A natively resolving IEM keeps its detail but sounds slightly slower and smoother.
Mids — Coloured, and more frontal and intimate. Contralto and soprano vocals and male falsetto come across as very immersive. He likens it to a W-shaped curve. If you want transparency and neutrality, he says this is not for you.
Bass — Smooth from mid-bass to sub-bass, with a decay he finds mesmerising. It keeps punch and authority and some speed, but it is not super fast. Even on balanced armature or planar bass it comes across as more engulfing and full-bodied.
Balance — He calls it an amazing tube dongle for anyone who wants that balance of musicality and technicality.
Critical observations
Pure tube, nothing to switch — Unlike the Nunchaku, the RU6 and the Beta XI2, there is no solid-state or transistor option. Andy sees that as the reason it can cost so much less, and says it is a purist design for tube lovers. He calls it a stripped-down Muse HiFi M6 Double: the same two JAN6418 tubes and similar power, without the extra features or the battery.
Power — Enough for his magnetic planar CJ20. From the 4.4mm output it also drove the FiiO FT7 headphone to what he puts at over 80% of that headphone's potential.
RF interference — None heard, with the stock cable or his DD HiFi cable. He says the Nunchaku and Beta XI2 pick up interference from 3G, 4G and 5G signals, and this one does not.
Heat — A temperature gauge held it at about 33°C after 4 to 5 hours of continuous running, in a tropical country. He says most powerful dongles run hot.
Battery drain — From a Xiaomi Mi 9T with a 4,000 mAh battery, it ran past 12 hours and he stopped measuring.
Design — Minimalist machined body with the tubes visible. USB-C on one side, independent volume buttons and the two outputs on the other.
Read this against your own profile — If you love tubes and a warm, smooth, immersive sound with an open stage, this fits. If you want a transparent, neutral, fast and analytical sound, or a solid-state mode on the same unit, Andy says it is not for you.
Honest limits — By ear only, with no measurements apart from the temperature gauge. No tracks are named. The video does not say whether the unit was a sample, a loan or bought. Specs are as stated in the video.
- Driver Details
- Two JAN6418 tubes, ES9028Q2M DAC (as stated in the video)
- Cable Connectors
- 3.5mm single-ended and 4.4mm balanced outputs, USB-C input
A pure-tube dongle for tube lovers: warm, smooth and airy, with real power, little heat, no RF noise and over 12 hours of battery from a phone. The trade is a slower, more coloured presentation and no solid-state mode.
<p><strong>Buy it if</strong>… you love tubes and want that organic, velvet-smooth, immersive sound in your pocket; you want a wide, airy stage; or you want cool running and long battery life from a tube dongle.</p><p><strong>Skip it if</strong>… you want transparency, neutrality or speed; you want a solid-state option; or you want gain switching and filters.</p>