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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-26 · 6 min read · Independent comparison
• Avantree Oasis Plus 2 — biggest strength: It's a purpose-built Bluetooth TV transmitter with optical and AUX input, two-headphone support, aptX Adaptive and aptX Low Latency, plus a remote for volume.
• Avantree Oasis Plus 2 — biggest trade-off: It only works with TVs that have Optical (TOSLINK) or 3.5mm AUX output. HDMI-only TVs, HDMI ARC/eARC and AV receivers are out, and it does not support Auracast or hearing aids.
• Fosi Audio MC331 — biggest strength: It's an all-in-one DAC, amplifier, preamp and headphone amp with Bluetooth, USB, optical, coaxial and RCA inputs, a 105W x2@4Ω power stage, pre-out, 3.5mm headphone out and a retro vacuum-tube plus VU meter look.
• Fosi Audio MC331 — biggest trade-off: It's a wired speaker amplifier at heart — it needs passive speakers to do its main job, and its Bluetooth codecs are limited to SBC and AAC.
• Who each pick is for: Avantree Oasis Plus 2 for private TV listening on one or two pairs of headphones. Fosi Audio MC331 for a small desktop or shelf hi-fi system.
The Avantree Oasis Plus 2 is a single-purpose device that solves one specific, very common problem: you want to watch TV late without blasting the room. It takes audio from your TV's Optical (SPDIF) or AUX output and sends it wirelessly to Bluetooth headphones or Bluetooth speakers. That's the whole job, and the design leans into it.
Two details stand out. First, it supports up to two Bluetooth headphones at once, which matters more than it sounds. Couples who watch together at different volumes, or a family member who needs extra loudness, can both stay in the loop. Second, the included remote and on-unit buttons let you adjust volume without touching the TV settings or getting up. That's a small convenience that turns into a big one over a hundred evenings.
Buy it if your TV has optical or AUX out and you mainly want private or shared headphone listening. Skip it if your TV is HDMI-only, you use an AV receiver, or you need a hearing-aid-compatible solution. It's also not the pick if you're trying to power passive speakers — that isn't what it does.
Fosi Audio MC331: Who It's For
The Fosi Audio MC331 is the opposite kind of product: a compact integrated amplifier that also happens to be a DAC, preamp and headphone amp. If you own passive bookshelf speakers and want a small, tidy way to drive them while juggling several sources, this is the design brief.
Connectivity is the headline. It accepts Bluetooth, USB, optical, coaxial and RCA, so a computer, phone, CD player or a turntable with a built-in phono preamp can all live on the same desk. Switching between them is done with the included remote. Power output is rated at up to 105W x2@4Ω, which is plenty for typical bookshelf speakers in a nearfield or small-room setup. There's a pre-out for building a 2.1 system, and a 3.5mm headphone output for late-night listening without waking anyone.
Then there's the character. The 5725W vacuum tubes and the VU meter give it a warm, retro look that's a genuine design choice, not an afterthought. Fosi also makes the tubes replaceable, and lists compatible types including 5654W, 6AK5, 6AK5W, 6Zh1P, 6J1, 6J1P, WE-403A, 403B, EF95 and other 7-pin tubes. Note that the tubes currently used (5725W and 6J1) ship randomly and can't be specified, so if you want a particular flavor you'd be sourcing tubes yourself.
Buy it if you want one box to handle speakers, headphones and multiple digital and analog sources, and you like the tube-and-VU aesthetic. Skip it if you only need private TV headphone audio, or if you rely on high-end Bluetooth codecs — the MC331's Bluetooth is SBC and AAC only.
Side-by-Side: Which Should You Choose?
• Best for private TV listening → Avantree Oasis Plus 2. Optical or AUX in, Bluetooth out to headphones. That's its entire reason to exist.
• Best for two listeners at once → Avantree Oasis Plus 2. It supports two Bluetooth headphones simultaneously; the MC331 has one headphone jack.
• Best for source variety → Fosi Audio MC331. Bluetooth, USB, optical, coaxial and RCA versus the Avantree's optical and AUX inputs only.
• Best for a turntable or CD player setup → Fosi Audio MC331. RCA input and pre-out make it the natural center of a small analog-plus-digital system.
• Best for low-latency wireless audio → Avantree Oasis Plus 2. aptX Adaptive and aptX Low Latency help keep audio and picture in sync; the MC331 uses SBC/AAC.
• Best for a minimalist desk → Fosi Audio MC331. It's a compact all-in-one, but it still needs speakers and a power adapter (24V 4.5A) nearby.
• Best for a wall-mounted TV with no room for gear → Avantree Oasis Plus 2. Small, remote-controlled, and it doesn't need speakers to work.
• Best for easy volume control without getting up → both, honestly. Each ships with a remote; the Avantree's is aimed at TV volume, the Fosi's at source switching plus bass and treble.
In my opinion, these two barely compete — they solve different problems, so the right answer is the one that matches your setup. If your goal is watching TV through headphones, alone or with a partner, I'd buy the Avantree Oasis Plus 2. It's built for exactly that, it handles two headphones, and the optical passthrough lets a soundbar stay in the mix.
If your goal is a real little hi-fi system — passive bookshelf speakers, several sources, a headphone jack and a warm tube look on your desk — I'd buy the Fosi Audio MC331. Just confirm your TV's audio output type before ordering either one, and check the current price on Amazon, since that's the one thing specs can't tell you.
The Avantree Oasis Plus 2. It's designed to take optical or AUX TV audio and stream it to Bluetooth headphones, supports two headphones at once, and includes a remote for volume. The MC331 can feed one pair of wired headphones, but that's a secondary feature.
Only if your TV has an Optical (TOSLINK) or 3.5mm AUX audio output. It does not work with HDMI-only TVs, HDMI ARC/eARC, or AV receivers. Check your TV's ports first — this is the most common reason people buy the wrong device.
Yes, if they're passive speakers. It's rated up to 105W x2@4Ω, which suits typical bookshelf models. It won't drive powered/active speakers, since those have their own amplification built in.
No. Its Bluetooth codecs are SBC and AAC. For better fidelity, use its USB, optical, coaxial or RCA inputs instead — the built-in DAC handles those digital sources.
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See also: Fosi Audio MC331 vs DANFI AUDIO DF Vinyl Record Player, HomeSpot Over-Ear Headphones Transmitter vs Fosi Audio DS3, Feipool USB C Splitter vs Bawanfa Plus USB C Audio