Singxer SA-1 ($599): Taking the sting out of your budget…

Singxer SA-1 ($599): Taking the sting out of your budget…



From the site, “Since 2011, Singxer has operated as an ODM and OEM in the audio industry as well as developed their own DACs and digital interfaces. Best known for their work in digital audio, they’ve made technical achievements in clock systems, phase-locked loop technologies, and more. In a bit of a departure for a company that so heavily favors digital products, Singxer has now released the SA-1, a fully balanced pure analog class A amplifier.

Call it beginner’s luck or pure talent: Singxer has knocked this one out of the park. The SA-1 offers superb amplification, vanishingly low noise floor, and nominal distortion. It’s a great choice for anyone looking to graduate to a high-end balanced amplifier that can double as a preamp.”

Hearing about the SA-1 from @Audiofool, he came away telling me that this was one fine amp and one of the cleanest sounding amps he had heard in a good long time. He was gracious enough to put me in contact with John from Apos. We discussed a collaborative effort, and John mentioned that he had also liked my Caspian review. I indeed did like the Caspian and mentioned how it was a brave effort putting together a new headphone in such a collaboration as they had done. We agreed that I would be sent the SA-1 for a review. I also happen to have another amp in house with which I will compare the SA-1 as well. The unit will be returned to Apos upon the finishing of my review. I appreciate the collaboration and have signed up to continue with more of their products as need arises. I really like this approach and there is no pressure to provide a positive review. There really isn’t, and John asked for my honest assessment of the unit either way. As you will read below, there will be both good and less than good parts to the SA-1. That said, it is a fine unit, which I used across many reviews already.

Product highlights:

  • Fully independent class A analog amp
  • Super clean output with low distortion and low noise floor
  • Seven inputs and outputs
  • Fully balanced architecture
  • Headphone amplifier and preamplifier
  • Amplification type: Class A
  • Two gain modes: low/ high


  • Inputs: Balanced XLR, RCA
  • Outputs: Balanced XLR, RCA, Balanced 4.4mm, Balanced 4-pin XLR 4, Single-ended 6.35mm
  • SNR: 126dB
  • Dynamic range: 147dB @A-wt
  • THD+N: 
    • 0.000078% @balanced input and no output load
    • 0.000128% @balanced input and 33Ω output load
  • Noise level: 
    • 0.66µV @ Max output, SNR / DNR 147dB
    • 300nV RMS @ Low gain, A-Weighting, 20Hz-22kHz
  • Output power
    • 6480mW @ 32Ω
    • 2000mW @ 120Ω
    • 380mW @ 600Ω
  • Power supply: 100-240V AC, 50/60Hz
  • Dimensions: 9.2 x 6.6 x 1.8” (234 x 170 x 46mm)
  • Housing material: Aluminum
  • Color: Black
  • Weight: 3.9lbs (1.8kg)

What’s included:

  • 1x Singxer SA-1
  • 1x Power cable

Gear Used/Compared:

Kennerton Rögnir

Fir Audio Frontier Series Krypton 5

Empire Ears Legend X

Earsonics ONYX

MBP/Burson Funk


Shanling M6 Pro


Stevie Ray Vaughan

Pink Floyd


Dave Matthews

Tommy Emmanuel

Tedeschi Trucks Band

Tinsley Ellis

David Bowie

Leonard Cohen

Los Lobos


The Allman Brothers



The unit was well packed in a plain box. Taking the (heavy) unit out, I was quick to note that the heft most likely came from the Class-A fully balanced headphone amp inside. Set up was easy as well. I utilized the RCA out connectors as well as the XLR connections to sources.


The SA-1 is a rectangular matte-black box made from anodized aluminum. Minimalistic, the amp will sit peacefully on your desktop without fuss. Multiple switches cross the from, with fewer on back. The SA-1 can be used as a headphone amp or a pre-amp (used in conjunction with my iFi iCAN, see below). The only worry I have is the three toggle switches on the left face. That said I have used the Singxer for over three weeks without bother.

From left to right, the blue light signifies that the unit is on, either in pre-amp mode or headphone amp mode. To the right (middle toggle) is the switch determining whether the unit is run via RCA cables or XLR, A gain switch is the last toggle, going from “Low-Z” to “Hi-Z.” Contrary to what you think, the Low-Z provides a higher gain for “more output.” More sensitive headphones should use the Hi-Z setting but will require more volume input.

Three headphone inputs sit in the middle of the front. Left to right, there is 4.4bal, 3.5se and XLR bal. The majority of my listening time was from either the 4.4bal or XLR, but for comparative purposes the 3.5se was used with the excellent Earsonics ONYX. Last on the right is a very smooth volume pot, complete with a detent, which can be used to rotate the knob. Rarely with “normal” IEM’s and headphones did I go above ½-way. Especially in 4.4bal mode.

On the back you have the analogue inputs of both RCA and XLR. I utilized only the RCA. To the right of that you have the RCS and XLR analogue outputs. I utilized the XLR when going to my iFi iCAN. Sources used for that purpose were my MBP and Shanling M6 Pro.

On the bottom there are gain switches for each of the four differential amplifiers used in the SA-1. It should be noted that the unit should be powered off (not just turned off using the front toggle switch) before adjusting the gain settings.

The Singxer is built well, with no misaligned pieces or cheapness to it. I will state that the 4.4bal jack is a bugger to use, gripping the headphone jack quite tightly. Several times I had to hold onto the back of the unit in order to remove the headphone jack, lest the unit slide across my desk. Other than that, no problems with operation at all.


A fully Class-A amplifier with their own in-house designed XMOS processor and Singxer convertors, which are also utilized in some quite expensive DAC’s across the palette of audiodom. @wiljen does a much better job explaining the technicals than I do, so search out his review for that on ecoustics ( Suffice to say, the SA1 is a fully discrete, differential amplifier with balanced and single-ended input and output options as mentioned above. Listed as a Class-A amplifier, the majority of its time is a full Class-A device, unless extreme power is called for switching to a class AB amplifier to accommodate the increased load.   



The SA-1 is amongst the cleanest, clearest amps I have tested at pretty much any price point. The sound emanating from within is akin to the Questyle CMA Twelve (not the Master). While not as crisp as the Questyle, the comparison rings true. There is very little coloration from the SA-1 with regard to tone. If the song is bassy, it comes across through your headphones as bassy. If the piece is of a detailed quality, then it provides that detail as meant from the source. Not peaky at all, either there is very good 3-dimensiality here, especially at this price. The Questyle is bigger overall, but that should not diminish the SA-1 in the least. Expansive without being gargantuan. Details are portrayed at the micro level as well, with aplomb. I would call the overall signature vibrant. Not too bright, but certainly not dull by any means.


The SA-1 is one of the most neutral amps I have tested, and even when used as a pre-amp allowed the attached amplifier to show its characteristics. Pairing with the iFi iCAN did not taint or dim its warm characteristics in the least. Someone said that the sign of a good amp/DAC is to not get in the way or color the sound from the source. For the SA-1 I would agree, and if you are looking for an excellently clean, affordable desktop DAC/amp then the SA-1 should be seriously considered. Allowing bass notes to shine through from the songs, paired with the Earsonics ONYX the sound on ZZ Top’s Jesus Just Left Chicago came through as vibrant and deep. I won’t break this into my normal three separates but focus on the overall signature.

Soundstage has been dscribed as good but not great, with a lower ceiling than desired or some. I would state that the SA-1 is just fine in that regard, and again not cavernous or gargantuan; but very adequate. Since the SA-1 is of neutral quality, the sound signature takes on the characteristics of the source and headphones/IEMs. This is what could be asked of a neutral amp. Personally, I prefer the ability to tailor sound such as on the iFi combo I own. But if I had to choose a neutral signatured amp, the SA-1 would be right at the top.

The SA-1 functions very well using the 4.4bal or XLR, and you can tell most of the wizardry is aimed for that aspect. While the 3.5se is still good, I found using headphones or IEMs in that jack lacking in power. My preference was indeed for the 4.4bal or XLR jacks.

When compared to the Burson Funk, the Burson came across as brighter in signature and more powerful across the spectrum. Burson are near-legendary for their almost endless power and the Singxer cannot match the Funk for sheer power. If you prefer a more neutral signatured amp, then the SA-1 would be the choice. If you prefer pure power and the ability to hook speakers up as well then, the Burson is a very fine choice. You could even run the Singxer as the pre-amp to the Burson’s amp and have quite the duo. For the price, it would be a very fine system.


The SA-1 is an affordable alternative to the higher priced units many pine for and promote. To think that the quality of sound coming from the SA-1 can darn near match those higher priced, more thought of units simply shows how far the market has come. Does it match my iFi duo? No. Is it as good as a comparable Burson? Close, and provides a more neutral signature. But what the SA-1 provides goes beyond price and comparisons. The SA-1 provides listening pleasures with abound. You purchase it, you hook it up, and you start listening.

I have seen many posts, which add the SA-1 into their chain of units, and the user becomes very satisfied with the results. And after all, isn’t that the quest? In that purpose, the SA-1 is a very fine unit, and at a very affordable price (if you are in the mid-fi market). For its purpose, the SA-1 is well worth a look to me, and might just be able to shoehorn into your system nicely.

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