Good audio products are hard to find. However, that cuts two ways; there’s the “to find your prince, you have to kiss a lot of frogs” aspect that suggests there are a lot of mediocre audio devices, but there’s also the simple fact that the really good components like the Questyle CMA400i are always in high demand and on back-order around the world.
That’s not too hard to understand once you open the box and are met with an extraordinarily dense mid-sized aircraft-grade aluminium case with a well-crafted front and rear panel, basic function controls (it can be a DAC or a digital preamp), input LEDs (denting two coax, a Toslink, and USB on the rear panel), power (a simple toggle switch), and a volume control. Then look to the rear and those digital inputs are matched by a S/PDIF coax output, and both balanced and single-ended outputs (either fixed or variable line outs, with a nearby selector switch). Flip it over and there are four DIP switches on the PCB to adjust the output of the amplifier (for regular headphones or higher sensitivity earphones or CIEMs). The one minor criticism here is these switches are recessed and you need something like a toothpick to adjust them.
The amp has three headphone outputs: 2.5mm balanced jack, 6.35mm unbalanced jack, and four-pin XLR balanced. Balanced sounds best, as it seems to leverage the performance of Questyle’s Current Mode Amplification more effectively. Single-ended headphone played through the CMA400i sound excellent, but you are only really hearing what the CMA400i can do in low gear; balanced shows what it is really capable of.
An amp is only as good as the DAC that precedes it, and Questyle has never been shy of making a great-sounding converter. This model uses the AKM AK4490 chipset to great effect, delivering up to 32bit, 384kHz precision in PCM, and up to DSD256 on DoP downloads. Questyle uses its own ‘True DSD’ digital pathway that means there is no PCM transcoding for any DSD datastream. MQA is MIA.
The Questyle CMA400i is a detail hound, and that means it requires a diet of the finest digital audio data. That comes through even on prosaic closed headphones used for ENG (like the Sony MDR-7506 or Sennheiser’s HD-25 series) played through the single-ended minijack. Playing through a series of both stored and streamed files, any weaknesses in the recording chain or the encoding process were laid open for investigation, and yet the CMA400i is also extremely good at stepping past that detail and making the music a coherent, cohesive whole rather than a laboratory experiment. I played some old-school funk; the title track from Funkadelic’s Maggot Brainalbum [Westbound], primarily for that outstanding Eddie Hazel guitar solo. On highly detailed systems, this can sound disjointed and almost aggressively bright, but here it sounded precise and that showed why it’s perhaps one of the best guitar solos ever recorded.
Funkadelic also exposed two of the outstanding aspects of the CMA400i performance; deep bass and excellent dynamic range. Any track with George Clinton at the faders and Billy Nelson on bass is going to plumb the depths, but the depth, precision, and slam of that bass was surprising. You expect gut-crunchiness with large loudspeakers, but to perceive similar from a pair of IEMs is impressive. The CMA400i didn’t put a foot wrong elsewhere, but these three aspects of detail, scale, and bass are headliners. It nails these aspects better than many rivals.
The CMA400i is so damn good, it’s almost an existential threat to more upmarket devices. No, it’s not the reason why products like the full stack and the Golden stack have been discontinued, but when the performance of the CMA400i is this good, it gets difficult to praise products that deliver slightly better performance at almost 20x the price.
Questyle Audio CMA400i
Type: High-resolution desktop DAC/headphone amp
Inputs: S/PDIF coaxial RCA x2, Toslink optical, USB Type B
Headphone: Balanced 2.5mm mini-jack and four-pin DIN plug; unbalanced 6.35mm headphone jack
Digital: S/PDIF coaxial RCA
Analogue (fixed and variable): 2x RCA stereo single-ended, 2× XLR stereo balanced
Supported file formats: PCM to 32-bit/384kHz, DSD to DSD256 (native DSD)
Gain: 7.8dB (standard), 0.83dB (low)
THD+N: 0.0013% @ 1kHz (50mW, 32Ω), 0.0016% @ 1kHz (100)
Balanced output: 418mW@300Ω, 1200mW @32Ω
Single-ended output: 106mW@300Ω, 650mW @32Ω
Frequency Response: DC-100kHz (+0, -0.7dB),
DC-600kHz (+0, -3dB)
Dimensions (H×W×D): 55 × 279 × 189mm
Price: $799 US, £799
MANUFACTURER INFORMATION Questyle Audio Technology Co.,Ltd
Distributed in the UK by SCV Distribution
Tel: +44(0)3301 222 500