Description
FiiO K9 Pro ESS Desktop Bluetooth DAC/Amp
K9 PRO ESS
FLAGSHIP DESKTOP DAC AND AMPLIFIER
High performance DAC ES9038PRO*2 | THX-AAA 788+ Tech | Dual femtosecond clocks Qualcomm QCC5124 | Supports LDAC/aptX adaptive/aptX HD | Truly balanced design Dual voltage linear transformer | Wide connector selection | App control
Moves your human “core”, and not just by a little!
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.
Pure clean sound, satisfying even demanding listeners
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.
*As tested in FiiO Labs under balanced out.
Precise Design
Fully differential, fully balanced design
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.
Six-stage audio circuit, to reveal every last detail
Every audio signal goes through a mammoth 6-stage circuit to reproduce music as faithfully and as detailed as possible
Separated analog and digital sections, partitioned design
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.
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.
Electricity is the mother of sound
Immensely robust, Linear power supply
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.
Just pure sound, Isolated digital and analog power delivery
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.
* Due to the instability of the supply chain, some materials may be replaced due to shortage. The accompanying drawings are for reference only.
Quality and quantity, LDOs for each circuit stage
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.
Dual femtosecond clocks, Precise clock management
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.
MQA Renderer, Lossless sound reproduction
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.
*With an appropriate music player supporting MQA, the K9 Pro ESS supports up to 8x unfolding
Fast and reliable Hi-Res Bluetooth
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
Essentiality of volume adjustment
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.
Lighting up the mood
The RGB indicator lights surrounding the volume knob can light up differently depending on the currently playing sampling rate.
Dial it in with three gain levels
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.
Plentiful connectors to choose from
Front: XLR 4-pin, 4.4mm balanced, 6.35mm single-ended headphone outputs
Rear: 4.4mm balanced line in; coaxial, optical, Bluetooth, RCA, USB input; RCA SE out and XLR*2 balanced out
Side: USB Type-C port
Refreshingly modern, custom stand
The included custom stand not only reduces the amount of space the K9 Pro ESS takes on your desktop, it also allows for more efficient dissipation of heat through convection – making the stand a true example of both form and function.
A true Renaissance man
- Drive power-hungry headphones (desktop USB audio + Headphones)
- Connect to home audio setup (desktop USB audio + active speakers)
- Side-mounted Type-C port for easy connection to mobile devices
- RCA+XLR balanced line out (for active speakers, monitor speakers, external amplifiers)
- Connect to mobile devices (players, computers)
- App-controllable desktop amp Built-in Bluetooth Low Energy (BLE) technology allows you to use the FiiO Control App to control functions like filter selection, channel balance, etc. even when not in Bluetooth mode.
Packing list:
1. K9 Pro *1
2. Power cord*1
3. Square port USB data cable*1
4. Bluetooth antenna *1
5. 6.35mm male to 3.5mm female Headphone jack adapter*1
6. Quick start*1
7. Warranty card*1
8. Instruction card for voltage selection*1
9. Fuse*1
10. Voltage protection plug*1
General specifications
| Name / Model No. | K9 Pro ESS | Hardware solution |
DAC: ES9038PRO*2, USB: XMOS XUF208, Bluetooth: QCC5124, LPF: OPA1612 * 2, volume IC: NJU72315 * 2, AMP: THX AAA 788+ * 2, linear transformer：THAILIN/BingZi |
| Color | Black | Volume Scroll | Potentiometer+ADC Sampling |
| Weight | ≈2750g | Channel balance | L12~R12 (0.5dB per level) |
| Gain | L/M/H | FiiO Control | Surpported |
| Bluetooth format indication | Surpported | Sampling rate indication | Surpported |
| Firmware upgrade | System firmware and Bluetooth version can be upgraded via USB | Deep standby | Long press the multi-function button for about 3s |
| Low battery reminder | / | Dimensions | ≈200×224.5x72mm (excluding feet) |
| Bluetooth transmission | / | Bluetooth receiver (5.0) | AAC/SBC/aptX/aptX LL/aptX HD/LDAC/atpX Adaptive |
| Bluetooth format indicator | SBC: blue, AAC: cyan, aptX HD: yellow, aptX: purple, aptX LL: purple, LDAC: white, atpX Adaptive: green | Charging indicator | / |
| Maximum supported sampling rate | 384kHz-32bit/DSD256（USB DAC） | Recommended headphone impedance | 16~600 Ω |
| 192kHz-24bit (coaxial) | |||
| 96KHz-24bit (optical) | |||
| Buttons and interfaces | |||
| Button | Physical key + toggle switch | USB | Type-C, USB B (data transmission) |
| Single-ended line input interface | RCA socket | Balanced line input interface | 4.4mm balanced socket |
| Spdif in | Optical fiber socket | Digital coaxial input interface | RCA socket |
| Balanced output interface | 4.4mm socket, XLR4 balanced socket | Headphone output interface | Standard 6.35 mm socket |
| Balanced line output interface | XLR3 balanced socket | Single-ended line output interface | RCA socket |
| Power parameters | |||
| Power supply | AC 110-115V~/AC 220-230V~ （Recommended） | Battery capacity | / |
| Charging time | / | PO battery life | / |
| Audio parameters | |||
| Single-ended line output performance parameters | |||
| THD+N | ＜0.00042%(1kHz/10kΩ/dbA) | SNR | ≥123dB (dbA) |
| Crosstalk | ≥115dB (1kHz/10kΩ) | Noise floor | ＜1.9μV（dbA） |
| Frequency response | 20Hz~20kHz (-3dB) | Line Level | 2.5Vrms (1kHz/10kΩ) |
| Balanced line output performance parameters | |||
| THD+N | ＜0.00025%(1kHz/10kΩ/dbA) | SNR | ≥128dB (dbA) |
| Crosstalk | ≥125dB (1kHz/10kΩ) | Noise floor | ＜1.9μV（dbA） |
| Frequency response | 20Hz~50kHz (-1.5dB) | Line Level | 5Vrms (1kHz/10kΩ) |
| Single-ended headphone output performance parameters（6.35mm） | |||
| Continuous undistorted output power 1 | ≥1.1W（16Ω / THD+N＜1%， AUX IN) | Output impedance | ＜1Ω（32Ω） |
| Continuous undistorted output power 2 | ≥1.0W(16Ω/THD+N＜1%，UAC/SPDIF/BT IN) | Crosstalk | ≥75dB (1 kHz/32Ω，AUX IN) |
| Continuous undistorted output power 3 | ≥281mW（300Ω / THD+N＜1%，AUX IN) | THD+N | ＜0.00033% (1 kHz/32Ω/dbA) |
| Noise floor |
＜2μV（dbA，AUX IN) ＜3μV（dbA，UAC/SPDIF/BT IN） |
SNR | ≥129dB (dbA) |
| Frequency response | 20 Hz~50kHz (-1.5dB) | MAX Output Voltage | ＞26Vp-p |
| Balanced headphone output performance parameters（4.4mm/XLR4） | |||
| Continuous undistorted output power 1 | ≥1.1W（16Ω / THD+N＜1%) | Output impedance | ＜1Ω（32Ω） |
| Continuous undistorted output power 2 | ≥2.1W（32Ω /THD+N＜1%) | Crosstalk | ≥114dB (1 kHz，AUX IN) |
| Continuous undistorted output power 3 | ≥1.1W（300Ω / THD+N＜1%) | THD+N | ＜0.0003% (1 kHz/32Ω/dbA) |
| Noise floor |
＜3μV（dbA， AUX IN） 4.5uV(dbA,UAC/SPDIF/BT) |
SNR | ≥123dB (dbA) |
| Frequency response | 20Hz~50kHz (-3dB) | MAX Output Voltage | ＞52Vp-p |
Comparison
| Model | K9 Pro | K9 Pro ESS | |
| appearance |
Dimensions |
200*224.5*76mm (height including feet) | 200*224.5 * 72mm (height excluding feet) |
| weight |
About 2750g |
About 2700g |
|
|
Volume knob |
Stainless steel PVD silver |
Aluminum alloy PVD gold |
|
|
Heat emission hole |
/ |
On both sides |
|
| Material&color | All aluminum alloy, black | All aluminum alloy, black | |
| Interfaces | power supply | AC + built-in Linear Power Supply | AC + built-in Linear Power Supply |
| Digital input interface | USB; Optical; Coaxial; Bluetooth | USB; Optical; Coaxial; Bluetooth | |
| Analog input interface | RCA;4.4mm balanced input | RCA;4.4mm balanced input | |
| USB interface | USB B ;Type C | USB B ;Type C | |
| Headphone output | Balance: XLR-4;4.4mm; Single-ended:6.35mm/3.5mm |
Balance: XLR-4;4.4mm; Single-ended:6.35mm/3.5mm |
|
| Line out | RCA/Balanced XLR * 2 | RCA/Balanced XLR * 2 | |
|
Configuration |
Power supply unique design | Digital and Analog Isolation Design | Digital and Analog Isolation Design |
| Audio processing layers | 6 layers | 6 layers | |
| Clock design | dual mode dual crystal oscillator | dual mode dual crystal oscillator | |
| filter |
6 kinds |
7kinds | |
| USB CHIP | XMOS XUF208 | XMOS XUF208 | |
| MQA | Renderer | Renderer | |
| Bluetooth | QCC5124 | QCC5124 | |
| Audio clock | High precision PLL + dual crystal oscillator | High precision PLL + dual crystal oscillator | |
| Audio DAC | AK4499EQ*1 | ES9038Pro*2 | |
| Output mode | HP/LO/DAC | HP/LO/DAC | |
| Gain | Three gears | Three gears | |
| Amp chip | Dual THX AAA 788+ | Dual THX AAA 788+ | |
| Output performance |
Output power (PO) |
2000mW(32 Ω), 278mW(300 Ω) |
2100mW(32 Ω),281mW(300 Ω) Balance: 2100mW(32 Ω),1100mW(300 Ω) |
|
Output power (BAL) |
2000mW(32 Ω),1100mW(300 Ω) |
2100mW (32Ω) 1100mW (300Ω) |
|
| Peak output voltage | 51Vpp | 52Vpp | |
|
THD+N |
≤ 0.0003% | ≤ 0.00025% | |
|
SNR |
≥ 123dB | ≥ 129dB |
