FiiO DM15 R2R red

A year after the DM13, FiiO is back with a completely redesigned portable CD player. The DM15 R2R abandons delta-sigma conversion in favor of an in-house developed R2R digital-to-analog converter, adds a USB DAC mode, much more powerful headphone amplification, and an aluminum chassis topped with a tempered glass lid. The format remains compact and the whole unit runs on battery power: this is far from a simple nostalgic nod.

An R2R DAC with a discrete resistor ladder network

The DM13 used two Cirrus Logic CS43198 delta-sigma chips. The DM15 R2R takes the opposite path with a proprietary R2R converter, derived from the one FiiO uses in its K11 R2R and K13 R2R desktop DACs.

The principle is simple in concept, demanding in execution: a resistor ladder network directly converts each digital value into analog voltage, without relying on the massive oversampling or complex digital filtering typical of delta-sigma DACs. The DM15 R2R uses 192 thin-film resistors spread across four channels (48 per channel), selected for their 0.1% tolerance and low thermal drift (30 ppm). The topology is fully differential and operates in 24 bits.

The sound result tends toward a denser, more organic presentation than that of the DM13, with slight warmth in the mids and softened treble. It is a signature choice: advocates of analytical neutrality may prefer a delta-sigma DAC, but the R2R approach gives CDs a particular texture, smooth and natural, reminiscent of the good players of the past.

Headphone amplification that means business

The amplification stage, built around two SGM8262 operational amplifiers, gains considerably more power compared with the DM13. The 4.4 mm balanced output delivers up to 1,150 mW per channel into 32 Ω (815 mW on battery), or 74% more than its predecessor. The 3.5 mm single-ended output reaches 315 mW into 32 Ω, compared with 180 mW previously.

These figures are not purely theoretical. The DM15 R2R can drive home headphones such as the Sennheiser HD 600 without difficulty, which is rare for a portable CD player. Output impedance remains below 1 Ω, channel separation exceeds 100 dB in balanced mode, and the signal-to-noise ratio is above 112 dB. The supported headphone impedance range goes from 8 to 350 Ω.

Volume adjustment moves from a push button (on the DM13) to a rotary potentiometer, a welcome change for fine level control. The volume steps have been recalibrated for more gradual progression.

Four devices in a 471 g enclosure

The DM15 R2R is not limited to CD playback. It combines several functions within the same chassis, each accessible via the front-panel switches.

In USB DAC mode, connected to a computer, smartphone, or tablet via USB-C, it supports PCM streams up to 32-bit / 384 kHz and native DSD256. It works driver-free (plug and play) and benefits from the same R2R converter as CD playback, which gives the USB signal the same sonic signature.

In Bluetooth transmitter mode, thanks to the Qualcomm QCC3095 chip and Bluetooth 5.4, it sends the signal (CD or USB) to wireless headphones or a speaker. Supported codecs include SBC, aptX, aptX HD, aptX Low Latency, and aptX Adaptive, the latter dynamically adjusting bitrate to maintain a stable connection. Note: Bluetooth transmission goes through the Qualcomm chipset and not the R2R DAC, so the signal is reprocessed.

As a digital transport, the coaxial and optical outputs (shared on a 3.5 mm jack with a supplied adapter) allow connection to an external DAC. The coaxial output goes up to 24-bit / 192 kHz, the optical output to 24-bit / 96 kHz.

The DM15 R2R can also extract (rip) CDs to WAV files on a USB-C flash drive, while listening to the disc at the same time. Only FAT32 media of 32 GB or less are supported, and only the WAV format is available for extraction.

A chassis designed for two uses

The aluminum enclosure measures 144 × 137 × 25.5 mm. It is thicker than a 1990s Discman, but 2 mm thinner than the DM13. The 471 g weight adds a sense of solidity without becoming cumbersome in a bag.

The tempered glass lid reveals the spinning disc, an appealing aesthetic detail that recalls transparent CD players from the 1990s. The centering mechanism uses spring-mounted steel balls to make disc insertion and removal easier without scratching it. FiiO announces near-silent rotation, a point that had caused issues on some DM13 units.

In terms of ergonomics, all control buttons have moved to the front panel: play, pause, next and previous track, stop, equalizer selection, and the volume potentiometer. A small 0.96-inch TFT LCD screen (80 × 160 pixels) displays playback information, active mode, battery level, and equalization settings. It remains modest in size, but readable and functional. Physical switches handle input/output selection, bass level, and playback mode.

The supplied infrared remote control covers most functions (transport, volume, output mode) and makes sedentary use more comfortable, especially when the player is connected to an amplifier or speakers. The remote control’s CR2025 battery is not included.

Desktop mode and battery management

The 4,700 mAh (3.85 V) lithium cobalt battery provides around 7 hours of continuous CD playback and up to 11 hours in USB DAC mode. Charging takes about 2 hours via USB-C with PD 2.0 / PD 3.0 fast charging.

Desktop mode (D.MODE), activated by a physical switch on the back, bypasses the battery to power the player directly through the USB-C port. The battery is then neither used nor recharged, which preserves its lifespan during extended use on a desk or in a hi-fi system. If the battery drops to 0%, the player automatically recharges it regardless of the desktop mode setting, to avoid damaging it. In desktop mode, headphone amplification delivers its maximum power (1,150 mW in balanced mode), compared with 815 mW on battery.

Anti-shock protection and playback on the move

The ESP (Electronic Skip Protection) switch activates a memory buffer that pre-reads the disc: 60 seconds ahead for audio CDs, 120 seconds for discs containing MP3 files. This system reduces playback skips in case of vibrations or movement. It should be kept in mind that ESP involves compression of the signal stored in the buffer. In sedentary use, it can be disabled.

The player supports commercial audio CDs, CD-Rs, and CD-RWs, including burned discs containing FLAC, WAV, MP3, AAC, or WMA files. FiiO specifies that the DM15 R2R’s playback capabilities are comparable to those of the DM13 after firmware update, and that some high-capacity CDs may cause slight skips due to the constraints of a portable mechanism.

Equalization and sound profiles

The DM15 R2R offers three levels of bass boost (Magic Bass), activated by a physical slide switch. The first level adds a slight lift in the low end, while the second more clearly boosts everything below 300 Hz. The second level can veil the mids and treble, which makes it mainly useful with headphones or earphones with shy bass.

Eight preset equalizer profiles complete the setup: Jazz, Pop, Rock, Dance, Classical, Hip Hop, a standard profile, and a Retro mode that attempts to recreate the signature of CD players from before the high-resolution era. The combination of the three bass levels and the eight profiles gives up to 24 possible combinations. Equalization is active in all modes (CD, USB, Bluetooth).

Full connectivity on the front and rear

The front panel groups the two headphone outputs (3.5 mm single-ended and 4.4 mm balanced) and the switches. The rear concentrates the ports and secondary switches: one USB-C for DAC input and CD extraction, one USB-C for power, a combined 3.5 mm line/coaxial/optical output (with the supplied coaxial adapter), a 4.4 mm balanced line output, the desktop mode switch, and the ESP switch.

The line outputs provide a level of 3.3 Vrms on 3.5 mm and 6.5 Vrms on 4.4 mm balanced, which is enough to drive most integrated amplifiers or active speakers.

What changes compared with the DM13

The move from the DM13 to the DM15 R2R is not a simple cosmetic update. The converter changes technology (delta-sigma to R2R), headphone power increases by 66% in single-ended mode and 74% in balanced mode, USB DAC mode makes its appearance, volume switches to a rotary potentiometer, the screen gets larger, the lid becomes transparent, a remote control is included, and the aptX Adaptive codec is added to Bluetooth. The aluminum chassis replaces a lighter enclosure, and the format has been slightly refined (2 mm less in thickness). The DM13 remains in the catalog for simpler use or a tighter budget.

Technical Specifications

Design and Architecture

• Proprietary R2R resistor ladder DAC (192 resistors)
• Headphone amplification based on dual SGM8262 op-amp
• Main controller: GD32F305RET6
• Bluetooth receiver: Qualcomm QCC3095
• Custom CD mechanism and optical pickup
• Aluminum chassis
• 0.96-inch LCD display (80 × 160 px)

Key Features

• CD playback and USB DAC function
• Bluetooth transmitter mode
• Driverless mode (plug and play)
• CD ripping function
• Bass adjustment: 3 levels
• Equalizer: 8 built-in DSP profiles
• Programmable auto-off
• Firmware update via USB

Audio Compatibility

• USB DAC: up to 32-bit / 384 kHz
• DSD: DSD256 (native)
• Coaxial output: up to 24-bit / 192 kHz
• Optical output: up to 24-bit / 96 kHz

Bluetooth

• Version: Bluetooth 5.4
• Supported codecs: SBC, aptX, aptX HD, aptX Low Latency, aptX Adaptive

Headphone Amplification

• Unbalanced output (3.5 mm)
  • Power: up to 315 mW / 32 Ω
  • Signal-to-noise ratio: ≥ 111 dB
  • THD+N: < 0.025%
  • Crosstalk: ≥ 72 dB
  • Frequency response: 20 Hz – 80 kHz (± 2.9 dB)
  • Output impedance: < 1 Ω
• Balanced output (4.4 mm)
  • Power: up to 1150 mW / 32 Ω
  • Signal-to-noise ratio: ≥ 112 dB
  • THD+N: < 0.025%
  • Crosstalk: ≥ 100 dB
• Compatible headphone impedance: 8 to 350 Ω

Line Outputs

• Output level
  • 3.5 mm: up to 3.3 Vrms
  • 4.4 mm balanced: up to 6.5 Vrms
• Frequency response: 20 Hz – 80 kHz
• THD+N: < 0.025%
• Dynamic range: ≥ 106 dB

Power and Battery Life

• Built-in battery: 4700 mAh
• Battery life
  • CD playback: up to 7 h
  • USB DAC mode: up to 11 h
• Fast charging: PD 2.0 / PD 3.0
• Charging time: approximately 2 h

Connectivity

• 1 × USB-C (USB DAC)
• 1 × USB-C (power)
• 1 × 3.5 mm headphone output
• 1 × 4.4 mm balanced headphone output
• 1 × 3.5 mm line output (combined line / coaxial / optical)
• 1 × 4.4 mm balanced line output

Controls and Ergonomics

• Physical buttons: play / pause, next / previous track, stop, equalizer
• Volume knob
• Dedicated switches: input / output, bass, ESP, playback mode

Included Accessories

• USB-A to USB-C cable
• 3.5 mm to coaxial jack adapter
• Infrared remote control
• Quick start guide

General Information

• Dimensions: 144 × 137 × 25.5 mm
• Weight: approximately 471 g