FiiO DM15 Gets New AKM Delta-Sigma DAC Version

The FiiO DM15 with an AKM DAC was officially launched today (July 20) in mainland China. When the DM15 was first released, it featured an R2R DAC developed in-house by FiiO. Since DAC chips based on the R2R architecture do not appeal to everyone, FiiO decided to launch a version of its CD player with a delta-sigma DAC. In addition to this change, there were also changes to the output power, Bluetooth codecs, and more.

Update (August 17): The FiiO DM15 with an AKM DAC is now available internationally through FiiO’s official store on AliExpress.

DM15 Gets a Version with an AKM Delta-Sigma DAC

When the FiiO DM15 was first released, some users decided not to buy it because its DAC chip used an R2R architecture. This type of DAC has a sound signature that may appeal to some listeners, but its measurements are worse than those of delta-sigma DACs. For this reason, FiiO launched the DM15 with an AKM DAC.

In general, SNR, noise floor, and THD+N are worse in DACs based on the R2R architecture compared with delta-sigma DACs. However, this was not the only change made to the new version with an AKM DAC. New features were added, and changes were made to the output power and Bluetooth codecs.

Changes Resulting from Replacing the R2R DAC with a Delta-Sigma DAC

The version of the DM15 with an AKM DAC has a better signal-to-noise ratio (SNR) than the model with an R2R DAC. There was a 10 dB improvement, from 112 dB to 122 dB.

The THD+N (Total Harmonic Distortion + Noise) of the DM15 with a delta-sigma DAC is 0.0013%. This is significantly better than the DM15 R2R, which has a THD+N of 0.030%.

The noise floor at the headphone outputs of the DM15 with an AKM DAC also decreased compared with the version featuring an R2R DAC. At the single-ended (SE) output, it decreased from 8.5 μV to 3.4 μV. At the balanced output, it decreased from 15.8 μV to 4.6 μV.

Output Power Decreased on the DM15 with an AKM DAC

Unfortunately, the output power of the DM15 decreased in the version with an AKM DAC. Instead of delivering 1150 mW into 32 ohms through the balanced output, the DM15 with a delta-sigma DAC delivers 1100 mW. I do not believe this difference is significant in practice, but it does exist.

Support for an Additional Bluetooth Codec on the DM15 with a Delta-Sigma DAC

Like the DM15 R2R, the DM15 with an AKM DAC supports the aptX Adaptive, aptX, aptX HD, aptX Low Latency, and SBC Bluetooth codecs. However, with the switch to the Qualcomm QCC3086 Bluetooth chip, the DM15 with a delta-sigma DAC now also supports the aptX Lossless codec.

New Line-Out (LO) Volume Option on the DM15 with an AKM DAC

Previously, with the DM15 R2R, the line output (LO) could only be used with adjustable volume. Now, with the delta-sigma version of the DM15, it is possible to set the LO volume to a fixed maximum level. Note that when this new option is used, the headphone outputs are disabled.

Battery Life Decreased on the DM15 with a Delta-Sigma DAC

Unfortunately, the battery life of the DM15 decreased in the version with a delta-sigma DAC compared with the version featuring an R2R DAC. Instead of being capable of 7 hours of continuous playback, the DM15 with an AKM DAC achieves only 6 hours.

FiiO DM15 with AKM Delta-Sigma DAC: Specifications

General Parameters

• Bluetooth chip: Qualcomm QCC3086
• CD ripping support: Yes
• Coaxial output: 3.5 mm
• DAC chip: 2x AKM AK4493S
• Dimensions: 14.4 cm x 13.7 cm x 2.5 cm
• Display: 0.96-inch LCD with a resolution of 80 x 160 pixels
• Headphone outputs: 3.5 mm single-ended (SE) and 4.4 mm balanced
• Line output: 3.5 mm
• Line-out (LO) volume options: Adjustable volume and fixed maximum volume
• Optical output: 3.5 mm (Mini-TOSLINK)
• Physical buttons: Power On/Off, Play/Pause, Stop, Previous Track, Next Track, EQ, On/Off
• Physical switches: Outputs, Inputs, Bass, ESP, Desktop Mode
• Remote control support: Yes (included in the box)
• USB ports: 1x USB-C for data and 1x USB-C for power
• Volume control: Knob
• Weight: 471.5 g

Battery Parameters

• Battery capacity: 4700 mAh
• Battery life when playing music from a PC, smartphone, or tablet through the 4.4 mm output: Up to 9 hours
• Maximum battery life when playing CDs and using the 3.5 mm and 4.4 mm outputs: Up to 6 hours

Bluetooth Parameters

• Bluetooth version: 5.4
• Supported Bluetooth audio codecs for transmission: SBC, aptX, aptX HD, aptX LL, aptX Adaptive, aptX Lossless

Audio Parameters

• Native decoding via coaxial: 192 kHz/24-bit
• Native decoding via optical: 96 kHz/24-bit
• Native decoding via USB: PCM 384 kHz/32-bit and DSD256

Output Power Through the 3.5 mm Single-Ended (SE) Output

• 295 mW into 32 ohms in Desktop Mode

Output Power Through the 4.4 mm Balanced Output

• 1100 mW into 32 ohms in Desktop Mode

Launch, Price, and Availability

The FiiO DM15 with an AKM delta-sigma DAC is now available internationally in silver for US$254.78 through FiiO’s official store on AliExpress.