MIXED, the company seems to be more focused on desktop/portable solutions, this one is truly not playing in the same league, wide features, good audio results, headphone amp, big volume, full HD BT (aptx HD and LDAC), not remote control but FiiO Control app for phone/tablet using BT, a bit pricey compared to other DAC features, the old dual AKM dac version seems to be better on the paper but no longer available unfortunately…
FiiO K9 PRO ESS
igh performance DAC ES9038PRO*2 | THX AAA 788+ Tech | App control
Dual femtosecond clocks | QCC5124 Bluetooth chip | Truly balanced design
Supports LDAC/aptX Adaptive/aptX HD | Dual voltage linear transformer
Wide connector selection
Electricity is the mother of sound
Electricity is the mother of sound, so special attention was paid to optimizing the K9 Pro ESS’s power supply to ensure excellent sound. The K9 Pro ESS’s linear power supply, with its low-frequency transformer and 4 massive 4700uF capacitors, makes sure that the rest of the system gets abundant clean power.
Linear power supply
The digital portions of the K9 Pro ESS physically receive power separately from the analog portions, for effective shielding against audio interference between the two circuits. This ensures pure and faithful reproduction of your music.
Isolated digital and analog power delivery
Besides the special high-performance linear power supply, the power stabilization and filtering within the audio circuit is also a big contributor to the K9 Pro ESS’s excellent sound. Specifically, in each stage of the audio circuit, ultra-low-noise LDOs are employed for voltage regulation.
The THX AAA 788+ chips used in the K9 Pro ESS provide exemplary details and dynamics no matter if you are using low or high-impedance headphones. The K9 Pro ESS can produce an undistorted 1100mW* under a 300Ω load, and an undistorted 2100mW* under a 32Ω load, 50% higher than the original THX AAA 788 amplifier chips.
Inside the K9 Pro ESS are 2 ES9038PRO DAC chips, specifically designed for maximum performance in desktop-grade equipment. One ES9038PRO chip, with all of its 8 parallel outputs, is used for each channel to achieve richly detailed sound with minimal distortion.
Fully differential signals go through the DAC, volume adjustment, and amp for a truly balanced design. Such a design ensures minimal interference between different components in order to fully maintain all details and large dynamic swings in music for unmatched sound quality.
The PCB of the K9 Pro ESS uses a partitioned layout, wherein not only the power supply and signals are separated, but the analog signal loop is also put in an independent section, guaranteeing the integrity of the audio signal being processed.
Every audio signal goes through a mammoth 6-stage circuit to reproduce music as faithfully and as detailed as possible.
A dual-mode clock management design is utilized for the K9 Pro ESS. Under USB and Bluetooth decoding, dual asynchronous femtosecond clocks are used, while under optical and coaxial decoding, automatic PLL clocks are employed. A more precise clock management system makes it easier to handle any kind of source and maintain the maximum quality possible.
The K9 Pro ESS supports the unfolding of MQA tracks, allowing you to listen to high-resolution audio files that are not only reasonably sized, but also retain master-level sound quality that bring you directly into the recording studio.
The K9 Pro ESS employs the Qualcomm QCC5124 to handle Bluetooth duties, with support for formats such as LDAC, aptX HD and aptX Adaptive. This chip ensures that Bluetooth connections are both reliable and quick, satisfying both the low latency needs for games/videos and the high bitrate necessary for high-resolution audio. Bluetooth format support: AAC/SBC/aptX/aptX LL/aptX HD/LDAC/aptx Adaptive
Adjusting the volume may look like a simple concept, but a good execution of it is crucial to an excellent audio experience. The ADC curve reconstruction method of volume adjustment used in the K9 Pro ESS effectively minimizes any left-right channel volume imbalance and noise. It also results in a smooth change of volume across all levels. This attention paid to the simple process of volume adjustment is just another layer to making sure you truly savor your music with the K9 Pro ESS.
Choose between high, medium, and low gain with a physical switch to fit exactly your needs when listening to your particular pair of headphones. Thanks to the pure hardware gain circuit, even when listening at low gain with high-sensitivity headphones both dynamic range and musical fidelity remain uncompromised.
The RGB indicator lights surrounding the volume knob can light up differently depending on the currently playing sampling rate.
Front: XLR 4-pin, 4.4mm balanced, 6.35mm single-ended headphone outputs
6.35mm single end
XLR balanced output
Rear: 4.4mm balanced line in; coaxial, optical, Bluetooth, RCA, USB input; RCA SE out and XLR*2 balanced out
Type C port
Side：USB Type-C port