FiiO K19 DAC & Headphone Amplifier

Innovative, 31-band high-precision lossless PEQ

The K19 features DEL (Dual Engine Limiter) technology, and through proprietary algorithms, the K19 can apply various audio effects such as dynamic range compression (DRC) and dynamic range enhancement (DRE) as well as an advanced limiter to prevent clipping. Also on the K19 is an adjustable 31-band high-precision lossless PEQ*, which supports direct adjustment of PCM 44.1k-192k audio signals without resorting to sampling rate conversion (SRC). For each band, the gain can be adjusted between a range of +12--24dB and the Q value can be adjusted between a range of 0.4dB~128dB. And the PEQ curves don't have to be used only by you - PEQ presets on the K19 can be shared between users. Being able to import and export PEQ presets opens up a whole new dimension to sound adjustment!

*PEQ adjustment is supported on Windows and Mac computers, as well as with the mobile control app

ADI ADSP-21565 with SHARC+ core

For the first time in an FIIO product, the K19 flagship desktop DAC and headphone amplifier utilizes an ADI ADSP-21565 DSP chip with the SHARC+ core backed by a custom ultra-low phase noise femtosecond crystal oscillator. This DSP chip featuring a high clock frequency of 800MHz and capable of 64-bit double precision floating point calculations is what makes the 31-band high-precision lossless PEQ possible in the K19. The ADI DSP chip not only ensures that audio signals after PEQ adjustment are of high quality and with minimal distortion, it also helps to enable powerful system protection functions that safeguard both the K19 and the other devices and headphones connected to it.

Flagship ESS 8-channel | ES9039SPRO*2 DACS

Inside the K19 are two of the new ESS 8-channel ES9039SPRO DAC chips, featuring the fourth generation 32Bit HyperStream architecture and capable of ultra-high dynamic range with ultra-low noise. These DAC chips allow the K19 to output clearer and richer audio with plenty of detail.

8-channel THX AAA 788+ headphone amplifier

The K19 features a new headphone amplifier design consisting of an 8-channel THX AAA 788+ headphone amp architecture working together in parallel and backed by a high-voltage power supply. The THX amp chips are connected in parallel via 2×2 groups to make up a totally balanced, 4-channel amplification system. The result is enhanced transients, and high-power output up to 8000mW+8000mW with a 320 load - allowing the K19 to drive all kinds of headphones with ease.

Dual ACCUSILICON high-performance ultra-low phase noise femtosecond crystal oscillators

The K19 employs two industry-leading ACCUSILICON AS318-B ultra-low phase noise femtosecond crystal oscillators (45.1584MHz, 49.1520MHz), which are 100% pre-screened before being selected for use in the K19. These femtosecond crystal oscillators effectively reduce the impact of phase noise on audio signals and allow for accurate audio restoration and different sampling rates - resulting in purer and more stable sound no matter the source sampling rate.

Fully balanced design

The K19 processes audio signals through a fully differential chain - from the dual DACs, to the I/V conversion, to the low-pass filtering, and finally to the balanced headphone amplifier to ensure high dynamics and minimal crosstalk. Also, various parts of the audio circuits such as the IV, LPF, and preamplifier use multiple precision op-amps including the OPA2211 and the OPA1602 to ensure the K19 outputs stable, high-quality sound.

High-quality digital audio processing architecture

For the first time in an FIIO product, the K19 utilizes a powerful quad-core FPGA as a high-definition digital signal processing center. The FPGA is responsible for handling all incoming digital signals, including Bluetooth reception and decoding, USB decoding, coaxial and optical decoding, HDMI/ARC decoding, and DSP digital signal processing. These digital signals are directly transmitted through two sets of I2S channels to the dual ES9039SPRO DACS, ensuring minimal distortion and loss of audio signals in the digital audio processing chain.

New flagship, ultra-thin die-cast unibody shock- proof construction

The K19 comes with a brand new styling, made of a die-cast unibody aluminum alloy body for a totally seamless design. The aluminum alloy body is carefully polished by a multi-axis CNC machine to a quality befitting of a flagship. This aluminum alloy body not only features reduced thickness, but is also capably shock-proof. And when paired with the included stand, the K19 is simply stable!

A new HiFi direction, supports HDMI/ARC

HDMI IN and ARC capabilities are present in an FIIO desktop DAC and amp for the first time. The K19 supports decoding from HDMI2.0 input, HDMI output and HDMI ARC audio return channel functionality, opening the doors to a new way of experiencing an immersive audiovisual experience.

HDMI decoding/output: supports up to 192kHz/24bit sampling rate HDMI ARC: supports 44.1/48kHz sampling rates

Separated and shielded circuit boards

The digital and analog audio circuits of the K19 lie on separate boards for full isolation and greatly reduced interference. There are metal shields for the DSP board, DAC board, and the THX head-phone amplifier board, as a result of the digital board and module board adopting a compartmentalized aluminum alloy isolation design. These measures all help to minimize crosstalk to ensure signal purity. In addition, the honeycomb-mesh aluminum alloy body can also help to further reduce external interference, allowing you to enjoy pure, clean music.

Multi-stage analog power supply

The K19's analog audio circuit is powered by a multi-stage power supply. The numerous stages of the analog power supply mean that there are power control circuits for the digital-to-analog conversion, LPF, preamplifier, headphone amp and other audio circuit stages. Each stage uses a large number of precision LDOs for secondary voltage stabilization to ensure continuous pure clean power.

Dual internal and external heat dissipation, high energy coolly output

The K19's internal heat dissipation system consists of thermally conductive material being in contact with the chips inside, which transfers the heat from the chips to the thermally conductive material and finally to the aluminum alloy outer frame. In addition, the thermally conductive aluminum alloy body features a honeycomb mesh design, which allows for convection heat dissipation. The internal and external heat dissipation systems of the K19 allow the machine to consistently output high power without the user worrying about heat issues.

Six operating modes

USB decoding

the XMOS 16-core XU316 enables decoding up to 768kHz/32bit, DSD512, MQA full decoding

Optical input

capable of receiving optical input, for use as an optical decoder

Bluetooth input

the Qualcomm QCC5125 enables support for aptX HD/aptX Adaptive/LDAC codecs

Coaxial input

capable of receiving coaxial input, for use as a coaxial decoder

HDMI input

supports audio input from devices such as video game consoles/Blu-ray players/ set-top boxes

HDMI ARC

supports audio return from TVs and other devices

Four analog output + two digital output

PO+PRE OUT (default position): front headphone out+rear audio out (volume adjustable)

PO: audio output only from the front headphone jack (volume adjustable)

PRE OUT: audio output only from the rear connectors (volume adjustable)

LO: audio output only from the rear connectors (fixed level output)

COAXIAL: standard RCA connectors, digital output

OPTICAL: standard toslink connectors, digital output