I’d like to personally thank Leo from Questyle for his time, patience and generosity, without which this review would not have been possible.
Back in October 2024 we published out first look of Questyle’s new desktop all-in-one flagship, the CMA Eighteen Master. Following on the heels of the sleek and stylish CMA18 Portable (reviewed here), the desktop derivative is in every way a ‘grown up’ version of the portable, with a price differential ($2,999 vs $799) to match.
While it’s an unusual departure for me to be reviewing desktop gear, considering my focus in this publication has been exclusively portable, I’ve been curious as to how much of a difference desktop components can make when used with IEMs. Despite its overabundance of power and fully fleshed-out Class A Current Mode Amplification technology, switching between the CMA18 Portable and Master goes some way to answering that question.
But that’s not the only reason for this review. This isn’t just another gadget to throw on your desk. The CMA Eighteen Master combines premium materials with precision craftsmanship, making it feel like a luxury piece of equipment to go along with any sort of premium collection, be it headphone or IEM. And it’s not just about looks – this beast is built to last, offering a variety of controls that let you fine-tune your listening experience with ease.
With high-end components like a flagship Sabre DAC, the latest XMOS USB platform, and support for hi-res Bluetooth codecs like LDAC, the CMA Eighteen Master aims to provide an audio experience that’s as pure and natural as possible with an abundance of power and finesse.
So, how does it all come together when it’s time to listen? Well, let’s just say, if you’re looking for a DAC and amp to upgrade your portable sound when you’re not, er, portable, the CMA Eighteen Master may be exactly what you’ve been waiting for.
Build and design
The first thing that strikes you about the CMA Eighteen Master is its professional-grade build quality. With a sleek and minimalist design, it’s easy to see that the unit was made with high-end, studio-quality equipment in mind.
The chassis is crafted from sandblasted matte CNC aluminum, and it feels solid and smooth in hand, imparting a sense of luxury. Questyle’s attention to detail is evident in the quality of materials used and the precision of the laser-engraved text on the front, as well as the smooth resistance offered by the Alps potentiometer for volume control.
In terms of size, the CMA Eighteen Master is not excessively large, which is a plus for desktop use, but is very solidly built nonetheless. It strikes a neat balance between providing ample functionality and not overwhelming your workspace.
The front panel hosts a variety of control options, including toggle switches to select between headphone amplifier and DAC modes, a bias control switch to toggle between high and standard bias, and multiple source input buttons. These are intuitively placed and easy to operate, with illuminated lights indicating the quality of the music being played.
The bias control is a particularly intriguing feature. With the ability to switch between high bias (Class A mode) and standard bias (Class AB mode), listeners have the flexibility to choose between warmer, more power-hungry sound or a cooler, more energy-efficient experience.
In high bias mode, the unit runs hotter, and draws more power, but in return offers the unmistakably fuller Class A sound that fans of the genre adore. In standard mode, the unit runs cooler and provides a more traditional, albeit equally impressive Class AB experience.
Technical specs (and specialties)
Under the hood, the CMA Eighteen Master is equipped with the latest Sabre flagship ES9039PRO DAC chip, capable of decoding PCM files up to 768kHz/32-bit and native DSD up to DSD512. For those using optical or coaxial inputs, the device supports resolutions ranging from 44.1kHz to 192kHz at 24-bit.
Bluetooth connectivity – a nice-to-have feature in modern desktop all-in-one units – is very robust here, accommodating all the mainstream codecs (such as SBC, AAC and aptX), and two more advanced hi-res codecs aptX-HD and LDAC.
The amplifier section boasts a fully balanced architecture, delivering up to 2 watts into 32-ohm loads via balanced output and 1.5 watts into 32-ohm loads through the single-ended output. This power output ensures compatibility with a wide range of high-end headphones, providing ample headroom and dynamic range.
A standout feature is Questyle’s patented Current Mode Amplification technology, which I first got to experience in the CMA18 Portable. This design achieves ultra-high sound performance that closely mirrors the original recording, offering listeners a transparent and immersive audio experience. I’ll refer you to that review for a more detailed dive into the intricacies of CMA technology.
To manage the heat generated by processing high-definition audio, Questyle have used a PCB made from ultra high-end Rogers material, originally designed for military applications. It boasts a dielectric constant just one-tenth that of conventional PCBs, which according to Questyle, delivers a 30% reduction in distortion compared to its predecessor. This results in more expansive dynamic range and a quieter, more immersive background.
To ensure impeccable signal integrity, the digital power supply and amp/DAC power are completely isolated from one another. On the analog side, an independent NORATEL toroidal transformer paired with a Schottky rectifier guarantees the cleanest possible power delivery, enhancing audio purity and precision.
Functionality and features
CMA Eighteen Master is not just a DAC and headphone amplifier – it’s a versatile all-in-one unit – which is able to function in multiple modes. In DAC-only mode, the unit acts as a DAC and pre-amplifier, allowing you to pair it with an external amplifier or active speakers. You can also use it in headphone DAC mode, making it an extremely flexible device for a variety of audio setups.
The unit features a comprehensive range of input options. For digital sources, there are USB (both Type A and Type C), optical, and S/PDIF inputs, providing compatibility with a variety of devices, from desktop PCs to high-end audio players. The CMA Eighteen Master also supports Bluetooth, with upgrades to the latest Aptx HD and LDAC technologies, ensuring compatibility with high-quality wireless streaming.
The rear of the unit houses analogue inputs for turntables and other devices, along with preamp output options in both balanced XLR and unbalanced RCA. There’s even a toggle switch to adjust between fixed and adjustable output modes for the preamp, providing additional flexibility in setup. The addition of a Bluetooth pairing button and antenna further adds to the versatility of the device.
Somewhat surprisingly for a (mostly) analogue device, Questyle includes a full-featured remote control in the box. Ok, it’s a bit of a mismatched add-on – with buttons and functions that clearly don’t apply to the CMA Eighteen Master at all – but as an easy way to change inputs and volume from afar, it does the trick. And hey, it’s cool to watch that big volume dial turning ‘on its own’, as if by magic.
On the downside, there’s no room for balanced analogue inputs, either XLR or 4.4mm, which is a pity if you’re wanting to keep your input chain fully balanced from source. Another design choice that may be frustrating for some is the placement of the headphone amplifier gain control switch at the bottom of the chassis. For users who switch between different types of headphones, particularly sensitive in-ear monitors (IEMs) and full-sized headphones, this might be cumbersome.
Full technical spec list
- Flagship ESS Sabre ES9039PRO DAC.
- Questyle-patented Current Mode Amplification technology with high-grade audio and electrical components.
- USB-C and USB-B digital inputs, supporting PCM 44.1kHz-768kHz/32Bit and Native DSD up to DSD512.
- Optical and COAX inputs handle PCM 44.1kHz-192kHz/24Bit.
- Bluetooth with support for SBC, AAC, aptX, aptX-HD, and LDAC (up to 96kHz/24Bit).
- RCA analog input with standard level 2Vrms.
- Headphone outputs: 6.3mm, 4.4mm BAL, and 4-pin BAL.
- Bias and gain adjustments available via front and bottom panel switches.
- Pre-amp outputs include XLR and RCA, with adjustable output levels and volume control.
- Max headphone output power: 6.3mm – 188mW@300Ω, 1.5W@32Ω; BAL – 765mW@300Ω, 2W@32Ω.
- Ultra-low THD+N (<0.0003%) and wide frequency response (±0.2dB, DC-22kHz).
- Studio mode boosts RCA output to 14dBu and XLR output to 20dBu, with high SNR for pristine sound.
Continue to sound impressions…
