Headphone AmpOverreview

Singxer SA-1 V2

Name: Singxer SA-1 V2
Brand: Singxer

A $599 Class A amp that measures like a reference and is heard as either a straight wire or a soft, warm one — with its gain switches on the bottom.

33 sourcesUpdated 2026-10-25

$599Typical US price

Score aggregates reviewer opinions across topics.

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The short version

What to know.

A $599 balanced Class A headphone amp and preamp. Sources agree on two things: it is exceptionally quiet — no audible hiss with sensitive IEMs even on high gain — and its balanced outputs measure among the cleanest of any amp at the price, with the single-ended output a step behind. They also broadly agree that putting the gain switches under the chassis is a real nuisance and that the volume knob does most of its work in the last third of its travel. The splits: about 54% of the weighted opinion hears a neutral, transparent amp, while the rest hears a warm, smooth or soft one, and one level-matched and one blind comparison found no difference from cheaper amps. Power divides roughly evenly — the output is there, but the gain is low (0 or 11 dB balanced), so some owners with low-voltage sources or hard planars run out of knob. Build is praised by nearly everyone, against a small run of dead-channel and red-light failures over five years. The V2 has not been benched, and it is getting hard to find now that the SA-2 has arrived.

About this product

The 2023 revision of the 2021 SA-1: same discrete Class A circuit and chassis, with lower Low-Z output impedance and a revised board. Not the 2025 SA-2.

Singxer, a Guangzhou maker best known for USB interfaces and DACs, entered analog amplification with the SA-1: a fully balanced, fully discrete Class A headphone amp and preamp with XLR and RCA in and out, two balanced headphone jacks and a quarter-inch, a front-panel switch that raises the output impedance by about 10 ohms, and gain set by four toggles underneath. The V2, sold from early 2024 at the same $599, keeps that circuit and chassis and lowers the Low-Z output impedance.

It earned an unusual double reputation — one of the best-measuring amps ASR had tested, and a "Class A sound" favourite on the subjective forums. The arguments are about whether that sound exists, whether its low gain makes it feel underpowered, and whether the bottom-mounted switches are a dealbreaker.

A good fit for

Owners of both sensitive IEMs and full-size headphones who want one quiet amp
Balanced setups — XLR in, XLR or 4.4 mm out — and a desk that also needs a preamp
Listeners who want a measurably clean amp, or a gently smooth one, depending on which camp you trust

Think twice if

You switch gain often — the switches are underneath
You'll drive an HE6-class planar from a 2 V source
You'll use only single-ended outputs
You want a remote-controlled preamp

The reviewer consensus

Agreement &
disagreement.

4 / 7topics divide opinion

3 Mostly agree4 Divided opinions

Common ground5

Silent with sensitive IEMs, even on high gain
Balanced outputs measure among the cleanest at the price; single-ended is a step behind
Gain switches under the chassis are a nuisance
Steep volume taper — most of the action is past 2 o'clock
Runs cool for a Class A amp

Points of contention4

Sound: neutral and transparent vs warm, smooth or soft
Power: ample from the balanced outputs vs low gain that leaves hard planars short with a 2–4 V source
Build: tank-like chassis vs a small run of channel and protection failures
Value: strong at $599 vs matched by cheaper amps or beaten by rivals

A closer listen.

7 topics · 4 divided

Left: criticalRight: positiveTighter lines: more agreement

Choose a topic

Power

Leans positiveDivided opinions

Reviewer sentiment13 supporting sources

CriticalNeutralPositive

Band: opinion spread · Dot: weighted average

Sources split, and the split is about gain more than output. ASR drove an HD 650 to "insanely loud" levels, L7Audiolab measured the rated 10 W into 16 ohms and 5.5 W into 32, and reviewers ran an HE6, an HE6se and Dan Clark planars from it. The other camp finds it short: high gain is only 11 dB, so with a 2–4 V source an LCD-4 nearly maxes the knob, an HE6se owner calls it not good enough, and others call it underpowered. Owners who fed it a hotter source, or used its single-ended-in to balanced-out path (17 dB), report plenty of headroom. ASR found distortion rising earlier into loads of 50 ohms and below.

Measured

L7Audiolab measured 10 W into 16 ohms, 5.5 W into 32 and 3.1 W into 68 from the balanced output, with a 15.9 V RMS maximum. ASR found distortion load-dependent from 50 ohms down — rising above roughly 5 V into 32 ohms and 2 V into 16. Gain is 0 or 11 dB balanced-to-balanced, 6 or 17 dB from single-ended in to balanced out (eCoustics).

vs. listeners — The bench shows the rated output is there; the low gain explains the 'underpowered' camp. With a 2 V or 4 V source the volume knob runs out before the amp does, which is why Soundnews and owners recommend a higher-voltage DAC.

Where it splits

plenty of clean power from the balanced outputs53%

“With my Sennheiser HD-650 and its balanced cable, the SA-1 was able to drive it cleanly to insanely loud levels.”
Amir Majidimehr · Audio Science Review

low gain leaves hard loads short of volume47%

“Its high gain of 11 dB isn’t enough with low-sensitivity headphones”
Sandu Vitalie · Soundnews

Link to this topic

Transparency

Leans positiveDivided opinions

Reviewer sentiment20 supporting sources

CriticalNeutralPositive

Band: opinion spread · Dot: weighted average

Sources split. One camp, anchored by three benches, hears a neutral amp that gets out of the way: ASR heard superb fidelity, eCoustics and a Head-Fi reviewer call it one of the most neutral amps they have tried, and two owners who compared it level-matched or blind against cheaper amps could not tell them apart. The other camp hears a sound of its own — Class A warmth and liquidity (Soundnews), the smoothest, most relaxed tuning Audiophile Heaven has heard on the V2, an Asgard 3-like thickness and rounded transients on SBAF, and, from its critics, a soft, muffled or blunted presentation. SBAF's measurer also heard a glassy treble glare on his loaner. Everyone agrees the single-ended output is weaker than the balanced.

Measured

ASR measured SINAD of about 121 dB balanced in/out at 4 V and about 120 dB from RCA in to the quarter-inch jack; L7Audiolab measured 124 dB at 5.2 V on a pre-retail unit, with a slight roll-off at 20 Hz from the DC-blocking capacitors. SBAF's bench found the balanced path superb but single-ended out fed from balanced in clearly worse.

vs. listeners — Distortion and noise sit far below audibility on every bench, so the warm/soft camp can't be traced to frequency response or distortion at normal levels. Sources name other causes: the High-Z switch (audibly softer on low-impedance headphones), the weaker single-ended path, and unmatched levels — the one Reddit A/B that matched levels heard the SA-1 and a $150 THX amp as identical.

Where it splits

neutral and transparent — no sound of its own54%

“Overall performance was superb and incredible dynamics, detail and overall fidelity/transparency.”
Amir Majidimehr · Audio Science Review

warm, smooth or soft — a Class A character46%

“That beautiful Class-A midrange is still present, offering a slight warmth and a higher degree of emotion compared to traditional amplifiers.”
Sandu Vitalie · Soundnews

Link to this topic

The hardware

Specifications.

Checked 2026-10-25

Design

Form factor: Desktop
Amplifier: Solid-state · Four-way fully independent, fully discrete Class A

Output

Output power: Balanced: 10,000 mW @ 16 Ω · 5,500 mW @ 32 Ω · 3,100 mW @ 68 Ω · 2,000 mW @ 120 Ω · 380 mW @ 600 Ω
Output impedance: 1.1 Ω SE · 0.25 Ω bal.
Gain settings: 2

Connection

Analog inputs: XLR, RCA
Headphone outputs: 4-pin XLR, 4.4 mm, 6.35 mm
Line outputs: XLR, RCAvariable (preamp)
Preamp output: Yes
Power: Mains (internal PSU)

Physical

Weight: 1,800 g
Dimensions: 234 × 170 × 46 mm

Power ratings are for the balanced outputs; output impedance is the Low-Z setting (High-Z adds about 10 ohms). Manufacturer-published figures, not measurements · from shenzhenaudio.com, headphones.com, audiophonics.fr.

Follow the evidence

Sources 33

Read with context

Limitations & method.

As of 2026-10-25

What to keep in mind 5

A read of where the reviews landed as of October 2026. Most of the hands-on reviews and measurements are of the original SA-1; the V2 keeps its circuit, but nobody has measured a V2 or compared the two side by side.
The V2 is getting hard to find new now that Singxer has released the SA-2, so check stock — and the used market — before settling on it.
Owner star ratings skew positive, and the store ratings here are few and mostly from the original model.
How much power you get depends on your source: a DAC with 4–5 V outputs, or the single-ended-in to balanced-out path, gives the low-gain SA-1 much more headroom than a 2 V source.
Whether you hear warmth or a straight wire may depend on your headphones, your source, the impedance switch and whether you compare at matched volume.

Where to buy Product & retailer links

Singxer SA-1 V2 Amazon

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Singxer SA-1 V2

How the score adds up

What to know.

A good fit for

Think twice if

Agreement &
disagreement.

Common ground5

Points of contention4

A closer listen.

Power

Measured

Noise

Measured

Transparency

Measured

Features

Ergonomics

Build

Value

Specifications.

Design

Output

Connection

Physical

Sources 33

Limitations & method.

What to keep in mind 5