Questyle SIGMA Pro Review — Headfonics

Louis opinions the Questyle SIGMA Professional, a flagship transportable Bluetooth-capable DAC and Present Mode discrete engineered headphone amplifier. It’s presently priced at $899.00.

Disclaimer: I obtained this pattern in change for my trustworthy opinion. Headfonics is an impartial web site with no affiliate hyperlinks or standing. I thank Questyle for this chance.

Click on right here to learn extra in regards to the Questyle products beforehand reviewed on Headfonics.

This text follows our current scoring guidelines, which you’ll be able to learn in additional element right here.

Questyle SIGMA Professional Overview

Abstract

The Questyle SIGMA Professional Present Mode transportable amplifier and built-in DAC will cater greatest to audiophiles preferring an analytical character and a balanced sound signature over coloration and toasty-sounding parts.

Slide right here so as to add your rating on the gear!32 Votes

8.5

Execs

Studio-ish clear sonic profile with an in depth, balanced signature.

Visually interesting with a window to all of the parts.

Versatile and beneficiant IO.

Cons

Glass appears fragile, and one unintentional drop might be deadly.

No choices menu or app.

We lately coated Questyle’s flagship dongle, the M18i, which is a feature-packed transportable DAC amplifier dongle with Bluetooth functionality.

Nonetheless, the M18i design veered from their hallmark clear again, which allowed geeks like me to take a look at their handywork.

The uncovered circuitry is an endorsement of the corporate’s confidence in circuitry design, whereas others cover theirs and even cover specs to cowl up what they don’t need you to know.

Questyle will not be like that. They proudly showcase their craftsmanship, and their newest element launch brings to the desk that idea, plus wonderful sonics by way of using up-to-date parts.

At this time’s topic is the Questyle SIGMA Professional transportable DAC/Amp priced at $899. That is the subsequent step from the Questyle SIGMA non-Professional version and their new flagship mannequin.

This new SIGMA Professional mannequin has a few standout traits, which I’ll clarify in my full evaluation beneath, and evaluate it to Third-party rivals such because the iFi audio iDSD Diablo 2.

Options

One of many phrases that matches the Questyle SIGMA Professional properly is versatility. It’s a conveyable gadget with a desktop element character, rack mount handles, and a Professional studio-like sonic profile.

The Questyle SIGMA Professional combines a patented, proprietary headphone amplifier with a identified good twin mono DAC part in a relatively small chassis, and with a ton of connectivity choices within the combine. That may be my normal description of the SIGMA Professional.

The actual icing on the cake is that the SIGMA Professional can be utilized as a separate amplifier, a devoted DAC with preamp performance, with its beneficiant IO part, and it even has an analog recording characteristic.

Quite a lot of goodies have been stuffed within the sturdy chassis of the Questyle SIGMA Professional, together with Bluetooth functionality and LDAC wi-fi decoding, giving the tip person one more enter possibility.

DAC

The Questyle SIGMA Professional makes use of a three-tier DAC structure, or TTA decoding framework.

The DAC is a pair of pro-grade ESS ES9069 32-bit 2-channel chipsets in a dual-mono configuration. Very excessive dynamic vary, low distortion, and ultra-low distortion are a number of the highlights.

The SIGMA Professional can decode as much as DSD512 and PCM 32-bit/768kHz with extra MQA unfolding if wanted.

The entrance show provides you all the data that you must know, together with the digital format being fed by means of the DAC, the enter choice, and the achieve degree.

One factor I didn’t discover was a set of digital filters, as a result of there appear to be none accessible, despite the fact that it has develop into a standard characteristic on most transportable units right now.

More often than not, digital filters are delicate, however I do really feel as if the SIGMA Professional lacks some options since there aren’t any menu choices both.

Amplification

The Questyle SIGMA Professional amplifier part can be a TTA design that makes use of a patented Present-Mode amplifier implementation with a completely discrete balanced circuitry, with three output ports, and 4 separate inside amplifiers.

The underside line on headphone amplification is that they need to at all times be versatile sufficient to run power-hungry headphones and IEMs alike, and that’s a balancing act modern-day headphone amplifiers should take note of.

Questyle combats this by firstly designing the amplifier part to be output impedance steady.

Nonetheless, the facility rankings are all over. There’s a 1200 mW spec, however there’s additionally an 8-watt peak energy output ranking on their banner, which is outrageously excessive for a unit of this measurement. I’ll quote the 1200 mW ranking all day, not the opposite.

Apart from that, there’s additionally a peak output present itemizing of 5 amps and a 25Vp-p voltage ranking, which once more are good numbers for a unit this measurement.

Design

Many of the inside parts of the SIGMA Professional are seen underneath a clear glass, which is a typical design attribute of Questyle’s element line.

Questyle’s upfront design helps you to peek inside to see all of the parts neatly soldered onto a black PC board.

The outer chassis itself is constructed from aluminum and may be very sturdy. The glass on the back and front is a pleasant contact, however be sure to not drop the unit, as it’d crack the glass.

Weight and measurement are usually not too dangerous for transportable use. The dimensions and weight jogged my memory of an old school mechanical arduous drive. It’s a hefty little gadget, and all of the IO functionality makes me really feel as if the Questyle SIGMA professional was designed, or higher supposed, for residence use.

My solely fear is that when on the go, one drop or a tough blow will shatter the glass for certain. This one definitely wants a protecting case. Questyle can capitalize on this by providing one as an upsell accent. The SIGMA Professional deserves one.

One of many components that contributes to that is that the SIGMA Professional doesn’t have any floor that facilitates a agency grip on the unit. In reality, the glass makes it really feel slippery within the fingers. Once more, I’d hold this child at residence and take her outdoors solely on particular events.

I/O

The entrance panel IO is the best to explain, so let’s begin there.

There are three headphone output ports. There’s a 3.5mm port, a 6.35mm port, each single-ended, alongside a 4.4mm balanced port, which sits in between the 2 different ports. The headphone outs also can operate as selectable line outs.

The rear IO is extra complicated as a result of there are analog inputs and digital enter variants as properly.

On the analog entrance, there are two enter ports: a 3.5mm and a 4.4mm. I’m assuming the 4.4mm port makes use of balanced topology. On the digital entrance, there’s a coaxial or SPDIF enter with an optical enter.

Alongside these ports are two USB-C connections. One is for information switch to feed the DAC by way of an XMOS XU316, and the opposite is strictly used for charging the inner battery. I observed there was no UAC 1.0 help, so be sure your supply is UAC 2.0 appropriate.

The SIGMA Professional has plenty of IO for a conveyable. I’m wondering what you might feed that optical port on the transfer? We haven’t even talked about the Bluetooth but, which is selectable by way of the enter button, and one more choice to faucet into the SIGMA Professional.

One characteristic of excessive significance to Apple product customers is that the SIGMA Professional is Apple MFi Licensed. That ensures compatibility with iPhones, that means the USB ports eat small quantities of energy, and that additionally appears true when tapped into Android units.

Bluetooth

The Bluetooth part consists of a Qualcomm Snapdragon that may deal with codecs at as much as Sony-certified LDAC degree.

It really works underneath a 5.4 radio and in addition handles codecs like aptX Adaptive and aptX HD. The SIGMA Professional additionally has included the LE Audio low-energy Bluetooth format.

I don’t count on a lot from Bluetooth reception because it’s susceptible to dropouts round corners, however the SIGMA Professional did properly, and I may traverse a big open dwelling area with no obvious points.

The sound? It’s the everyday Snapdragon Bluetooth sound that I’d say 85% of what hard-wire setups can produce. There’s nonetheless a small quantity of loss within the high frequencies, and a really small subdue in transients, that’s it.

Battery

The SIGMA Professional makes use of battery energy properly, or so it appears, since I observed no battery drain when the unit is off, that means there’s no standby battery drainage. Even when it’s on, there’s no battery drain, it appears, till you crank the amount.

The battery itself is a 4300mAh Lithium-ion battery that has a 3.7v output capability and is charged with as little as 4.2v. Charging from zero takes round 2.5 hours utilizing a high-capacity charger.

What I like most in regards to the charging system is that it has a separate port from the info port, so you’ll be able to cost the battery whereas concurrently utilizing the SIGMA Professional. That’s setup for a desktop, and even as a central hub, with a kick-ass headphone out.

Battery life is listed as able to 12 hours of steady use. I obtained roughly 9 hours with delicate IEMs. That point diminished to underneath six hours when utilizing a high-current demanding planar headphone, which remains to be not dangerous underneath right now’s requirements.

Controls

Many of the controls are positioned on the aspect of the small show panel up entrance, and near the amount knob.

The amount knob itself is knurled and has a visual orifice for a set screw. The knob appears to be manufactured from steel, most likely aluminum, and in addition has a push-to-mute characteristic.

The button array consists of 4 push buttons that management the facility on/off, achieve, output, and the supply choice. There, you choose your enter technique, both digital, analog, or Bluetooth.

The achieve characteristic has three settings: low, excessive, and studio mode, which produces the best quantity setting. The output swap additionally doubles because the IEM or HP output mode selector, which supplies you one other two extra ranges of achieve management.

I’m considerably upset as a result of lack of onboard options like digital filters and display screen time-out changes, however Questyle was going for a simple-to-operate gadget, and so they did accomplish that in spades.

Packaging & Equipment

The packaging has a timeless white and black exterior with illustrations on the front and back. The within is all black, and the primary unit might be discovered sitting comfortably inside a cardboard mildew.

You’ll additionally discover a relatively good, cloth-wrapped, four-foot twin USB-C cable with a full-sized USB adapter. There’s no Apple Lightning connectivity for older items included, although compatibility is assured, simply not out of the field.

The remainder of the contents consists of paper. There’s a guaranty registration type and a relatively thick person’s handbook, which is written in a number of languages.

Sound Impressions

Essentially the most upscale headphone I used with the Questyle SIGMA Professional is the HIFIMAN HE1000 Unveiled. However I additionally used the Sennheiser HD 490 PRO Plus and the HEDD Audio HEDDPhone D1, in addition to ORIVETI’s Grand Supremacy and FiiO’s FX17.

I fed the SIGMA Professional identified FLAC recordsdata by way of a customized Home windows 11 PC utilizing Foobar. I additionally used an Android 16 cellular gadget with VLC cellular and the JetAudio + app.

Abstract

What I bought from the Questyle SIGMA Professional’s sonic signature is that it’s all about neutrality. That facilitates the SIGMA Professional to supply a efficiency that permits you to see by means of a transparent window what the supply is attempting to feed your ears.

Some may discover it too impartial, however it’s labeled as a Skilled studio sound gadget, insinuating monitoring roots on the design desk. If that’s what you’re searching for, right here it’s. It even says so on the field: skilled studio sound, made transportable.

The Questyle SIGMA Professional has a vibrant high finish alongside a midrange that appears to be the middle of attraction. The bass is as impartial because it will get and isn’t emphasised. I’d even name it restrained or unadorned.

I additionally detect a distinct segment right here for producing nuances, microdetails, and its uncolorated character works in its favor to supply a number of element that different combos miss, particularly dongles and lower-tier DAC amp combos.

The Questyle SIGMA Professional produces a crystalline model of what’s interpreted by way of the enter. However what I like most in regards to the SIGMA Professional’s sonic signature is the just about analog sonic character it produces from digital codecs, which retains this mannequin from sounding sterile with a touch of wanted heat.

Staging & Dynamics

The Questyle SIGMA Professional produces what I name a centered sonic signature. Each factor is produced with a number of dynamics, however on the similar time, all components sound very centered, making it simple to differentiate what’s inside a recorded monitor.

The soundstage measurement, peak, width, and depth are principally decided by the headgear getting used. However the SIGMA Professional tends to favor depth and peak over different points.

Width is sufficiently represented, however there’s a bent to come back throughout because the narrowest a part of the staging capabilities.

That, at occasions, can alter left-to-right placement, however the SIGMA Professional remained managed by not condensing components, however relatively by bringing them into focus in a extra ahead and centered method.

Click on page 2 below for my recommended pairings and selected comparisons.

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