Questyle M15C silver

The Questyle M15C is a portable headphone preamp designed to deliver a faithful audio experience. This model belongs to Questyle’s M series, positioned between the M12i and the M15i.

A concentration of technology in an elegant chassis

The M15C sports a unique, eye-catching design that won’t go unnoticed. Its unibody machined aluminum casing features a Kunlun glass front panel, offering a fascinating view of the internal components. This design is not only aesthetic, but also functional. Two LED indicators are visible through the glass: one for data transmission and the other for gain selection.

The matte black aluminum body gives the M15C a premium, robust look. Its compact dimensions (61.9 x 27.9 x 12 mm) make it an ideal companion for on-the-go use. On the side, there is a physical button to switch between low and high gain modes.

At the heart of audio performance

The M15C is equipped with the Cirrus Logic CS43198 DAC, a chip renowned for its high-level audio performance. This setup allows the M15C to support PCM up to 32-bit/384 kHz and DSD up to DSD256.

Amplification is handled by two of Questyle’s proprietary SiP (System in Package) modules, using their patented Current Mode Amplification (CMA) technology. This architecture delivers impressive output power while maintaining extremely low distortion.

Extensive connectivity and compatibility

The M15C features an asynchronous USB-C input for easy connection to smartphones, tablets, and computers. On the output side, it offers an unbalanced 3.5 mm jack and a balanced 4.4 mm Pentaconn jack, providing great flexibility with different types of headphones and earphones.

The M15C’s compatibility is remarkable. It works driver-free with Android devices, iOS (via an adapter), Windows, and macOS. This versatility makes it an ideal choice for mobile audiophiles who use multiple sources.

A warm, detailed sound signature

The M15C stands out with a slightly warm sound signature that smooths out challenging recordings without sacrificing detail. This characteristic is unique within Questyle’s M series, as other models tend to deliver a more neutral or brighter sound.

The soundstage is wide and well-defined, with excellent instrument separation. Bass is present and well-controlled, without bleeding into the mids. The mids are natural and well balanced, while the highs remain detailed without harshness.

Intelligent power management

Questyle has integrated a TOREX power management module into the M15C. This technology enables precise control of power consumption, preventing overheating and preserving the source device’s battery. It’s a major asset for extended use with a smartphone.

The M15C versus its siblings

Compared to the M15i, the M15C offers similar performance at a significantly lower price. The main differences lie in the choice of DAC (Cirrus Logic for the M15C, ESS for the M15i) and the maximum supported sampling rates. The M15C positions itself as a more affordable alternative without major compromises on sound quality.

Compared to the M12i, the M15C brings a significant improvement in power and sound quality, while retaining a compact form factor.

Frequently asked questions

Does the M15C require an additional amplifier? No, the M15C already integrates a powerful amplifier capable of driving most headphones and earphones on the market, including planar models known to be difficult to power.

What is the M15C’s battery life? The M15C does not have an internal battery. It draws power from the device it’s connected to. Thanks to its efficient power management, the impact on your smartphone or tablet’s battery life remains limited.

Is the M15C compatible with music streaming services? Yes, the M15C works perfectly with all streaming services, whether Spotify, Tidal, Qobuz, or others. It can decode MQA streams, which is a plus for Tidal HiFi users.

Can the M15C be used as an external DAC for a computer? Absolutely. The M15C can serve as a high-quality external DAC for your computer. It is automatically recognized by Windows and macOS without the need to install additional drivers.

Is the M15C suitable for sensitive in-ear monitors? Yes, thanks to its gain switch, the M15C adapts to both power-hungry headphones and sensitive in-ear monitors. In low-gain mode, background noise is imperceptible, even with very sensitive IEMs.

Technical Specifications

Portable Digital-to-Analog Converter Specifications

• Headphone amplifier: 8 - 600 Ω
• Automatic gain adjustment
• Cirrus Logic CS43198 DAC chip
• MFI (Made for Apple) certification
• Compatible with iOS, Android, macOS, Windows, HarmonyOS

Build

• CNC-machined aluminum body
• Kunlun glass (shatterproof and scratch-resistant)

Audio Technology

• Amplification: Proprietary 4-channel current-mode amplification technology
• Digital-to-Analog Converter (DAC): ESS Sabre ES9281AC
• Patented dual current-mode amplification SiP module
• TOREX power management module

Connectivity

• Asynchronous USB Type-C port
• 3.5 mm unbalanced mini-jack output
• 4.4 mm balanced Pentaconn output
• USB controller for optimal compatibility
• Gain selector

Audio Performance

• Resolution: 32-bit, 384 kHz, DSD 256
• Frequency response:
  • ± 0.1 dB (20 Hz - 20 kHz)
  • ± 1 dB (20 Hz - 80 kHz)
• Total Harmonic Distortion and Noise (THD+N): 0.00028%

Output Power

• 3.5 mm unbalanced output:
  • Load impedance = 300 Ω
  • Output power = 10.72 mW
  • THD+N = 0.0003%
• 4.4 mm balanced output:
  • Load impedance = 300 Ω
  • Output power = 42.79 mW
  • THD+N = 0.0003%

Indicators

• 1 LED: Sampling rate < 48 kHz (PCM)
• 2 LEDs: Sampling rate > 48 kHz (PCM or DSD)

Compatibility

• Devices: Smartphones, tablets, computers
• Formats: Local audio files, Qobuz, Tidal, Spotify, Apple Music
• Recommended use: Entry-level and mid-range headphones/earphones

Physical Characteristics

• Dimensions: 62 × 28 × 12 mm (L × W × H)

Contents

• Questyle M15C
• USB Type-C to USB Type-C cable
• USB Type-C to USB Type-A adapter
• User manual