iFi Audio iDSD Valkyrie black

The iDSD Valkyrie from iFi Audio is a digital-to-analog converter and amplifier for portable headphones. It features four Burr-Brown DACs in a hybrid multi-bit configuration, DSD1024 remastering, JVCKENWOOD’s K2HD technology, and eight digital filters. Its 20,000 mAh battery offers up to 18 hours of runtime, with a maximum output of 5,700 mW. It supports xMEMS transducers, making the Valkyrie the most comprehensive portable device in the brand’s lineup.

An exceptional DAC from a renowned British lineage

iFi Audio traces its roots to Abbingdon Music Research (AMR), a company founded in London in 2000 and specialized in reference-grade high-fidelity electronics. AMR built a strong reputation with components like the CD-77 player, which already used the legendary multi-bit Philips TDA1541A DAC. As music listening shifted toward portable use in the early 2010s, AMR created iFi Audio in 2012 to adapt its technical expertise to portable and personal audio needs. The philosophy remains unchanged: bring studio-grade technologies into compact, accessible formats.

The iDSD Valkyrie follows this tradition by adopting concepts developed for the Pro iDSD, the mastering converter in the AMR range. The same team of British engineers designs products for both brands, ensuring technological continuity between reference fixed solutions and transportable devices. This approach explains the presence of technologies usually reserved for professional studios, such as DSD1024 remastering or the analog XBass II, XSpace, and XPresence processing.

Quadruple DAC architecture: where vintage meets modern

At the heart of the Valkyrie are four Burr-Brown DSD1793 DACs configured in a hybrid multi-bit architecture. This four-chip interleaved configuration is directly inspired by the legendary Philips TDA1541A, considered the “king of multi-bit DACs” in the 1980s–1990s. This component, used in iconic CD players from Marantz, Cambridge Audio, or Sony, employed a technique called DEM (Dynamic Element Matching) to reduce conversion errors. The Valkyrie’s configuration reprises this principle by mixing eight pairs of differential signals to capture the impactful sonic character of historic multi-bit chips, while benefiting from the low-level linearity of modern Burr-Brown components.

To minimize channel crosstalk, the analog path is built on a dedicated board, physically isolated from the digital components. This strict separation ensures impeccable channel separation and maintains linearity across the full dynamic range. The four DACs operate in a differential configuration, an approach first introduced by AMR in its CD-77 and later adopted by Marantz in its reference players such as the CD-94 mk2. This architecture doesn’t just multiply processing power: it allows the Valkyrie to natively handle PCM files up to 768 kHz and DSD512, with remastering available up to DSD1024.

DSD1024 remastering and K2HD: two studio technologies

The Valkyrie’s DSD1024 remastering is powered by a custom FPGA programmed by iFi Audio. This technique, similar to the one used in Sony mastering studios, artificially increases the resolution of any audio file while reducing distortion. The process converts files into DSD streams at 1024 times the CD’s native sampling rate (44.1 kHz × 1024 = 45.158 MHz). At this resolution level, even the tiniest details of the original recordings are preserved and reproduced with a precision that is nearly indistinguishable from a studio master.

The K2HD technology, developed by JVCKENWOOD in 2007, complements this remastering. K2HD is a system designed by engineers at Japan’s Victor Studio after they observed that, contrary to digital theory, audible differences remained between an original master and its digital copies. These engineers discovered that electrical distortions (jitter, ripple) occur during recording and playback, degrading sound quality even when the binary data remain identical. K2HD corrects these issues by restoring the natural harmonics in the high frequencies that are lost during CD formatting. The Valkyrie offers two modes: K2 preserves the file’s native resolution while restoring harmonics, whereas K2HD first up-samples to 192 kHz/24-bit before applying waveform correction. The K2 parameters were selected from 4 trillion possible combinations via listening tests conducted by Victor Studio engineers across all musical genres in their catalog.

Eight digital filters to sculpt the sound

Beyond K2 and K2HD, the Valkyrie offers six additional digital filters allowing fine-tuned sound adjustment according to preferences and playback equipment:

• Bit-Perfect: linear-phase filter that preserves the digital data in full, without modification.
• Standard: classic FIR reconstruction filter used in most CD players, producing a focused soundstage and controlled treble.
• Minimum: minimal filtering with reduced pre-ringing and post-ringing (32 taps). A compromise between Bit-Perfect and more complex filters.
• GTO (Gibbs Transient Optimal): optimizes transient response for faithful reproduction of instrumental attacks.
• Apodising: eliminates pre-ringing by introducing slight post-ringing, often appreciated for vocals and acoustic instruments.
• Transient Aligned: aligns transients for increased temporal coherence across frequencies.

This palette of eight options (six standard filters + K2 + K2HD) makes it possible to precisely adapt the Valkyrie’s sound signature to each headphone, each musical genre, or each listening preference. An open-back headphone will benefit from the Minimum filter for its transparency, while a planar magnetic model will shine with K2HD mode to recover high-frequency energy. Sensitive in-ear monitors will benefit from the Apodising filter to soften transients.

Powerful amplification and refined power management

The Valkyrie’s headphone amplifier delivers up to 5,700 mW peak (iFi Audio measurement) and 2,258 mW continuous into 64 Ω. This power, higher than that of the iDSD Diablo 2 (2,060 mW), can drive demanding planar magnetic headphones as well as multi-driver in-ear monitors. Output impedance remains extremely low: ≤ 0.3 Ω on the balanced 4.4 mm jack and ≤ 0.2 Ω on the 3.5 mm S-Bal jack. This near-zero value guarantees optimal control of the drivers, regardless of their nominal impedance.

For the most sensitive in-ear monitors, the iEMatch mode automatically adjusts gain and reduces background noise. This function, activated via the touch interface, significantly extends the range of compatible earphones without any compromise on sound quality. The Valkyrie also manages line outputs (4.4 mm, 3.5 mm, and RCA), allowing it to be used as a preamplifier in a living-room hi-fi system.

The 20,000 mAh lithium-ion battery (technology borrowed from electric vehicles) powers the Valkyrie for 18 hours of continuous use. Fast charging via USB-C PD / QC3.0 at 20 V takes only 2.5 hours. The device can also run on mains power thanks to the supplied iPowerX adapter, which incorporates Active Noise Cancellation 2 (ANC2) technology. This technique, inspired by noise-cancelling headphones, generates an opposite-phase signal to cancel incoming electromagnetic and radio-frequency interference. The iPowerX lowers the noise floor by more than 40 dB compared to standard wall adapters, ensuring ultra-quiet power with a background noise below 1 µV.

Lossless Bluetooth and xMEMS transducer support

The Valkyrie integrates Qualcomm’s QCC5181 chipset with Bluetooth 5.4, supporting the aptX Lossless codec. This codec, capable of reaching 1,200 kbps, transmits CD audio (44.1 kHz/16-bit) with no data loss whatsoever—a first in the Bluetooth domain. For high-resolution files, the Valkyrie supports LDAC and LHDC/HWA up to 96 kHz/24-bit, as well as AAC and SBC codecs for universal compatibility. This versatility makes the Valkyrie a reference Bluetooth source, rivaling wired connections in sound quality.

The Valkyrie also stands out with its native support for xMEMS transducers, an emerging technology in high-end in-ear monitors. xMEMS drivers use piezoelectric micro-speakers etched on silicon, producing sound via amplitude-modulated ultrasonic pulses. Unlike traditional moving-coil dynamic drivers, xMEMS offer an almost instantaneous mechanical response, near-zero phase shift, and an extended frequency range (20 Hz to over 40 kHz). This compatibility positions the Valkyrie among the rare portable DAC/amps ready for the next generation of high-resolution earphones. In-ear monitors equipped with xMEMS transducers require a constant bias voltage, which the Valkyrie supplies thanks to its dedicated electronic design.

Analog processing: XBass II, XSpace, and XPresence

In addition to digital filters, the Valkyrie offers three analog processing options to optimize listening according to headphone type:

XBass II restores low frequencies lost by open-back headphones. Due to their airy design, these models let low-frequency energy escape. XBass II compensates for this physical phenomenon by reinforcing the lower register without coloring the midrange or affecting dynamics. Open planar designs and electrostatic headphones particularly benefit from this processing.

XSpace creates an expanded sound field by applying proprietary crossfeed. This technique, particularly effective with closed-back headphones and in-ear monitors, reduces the exaggerated left-right channel separation typical of headphone listening. The result is closer to listening on speakers, with a more natural soundstage and reduced fatigue during long sessions.

XPresence pushes the midrange forward, making vocals more present and direct. This processing is useful for movie dialogue, podcasts, or certain music productions where voices lack body or are buried in the instrumental mix.

These three processes are activated independently and can be combined with the digital filters, offering an unparalleled palette of sound customization in a transportable device.

Technical specifications

Key features

• JVCKENWOOD K2HD technology for rich, emotionally engaging sound
• DSD1024 remastering that turns every audio file into an experience close to a studio master
• 4 interleaved Burr-Brown DACs for maximum fidelity
• Power and flexibility for all headphones and in-ear monitors, even the most demanding
• Lossless Bluetooth and high-resolution compatibility
• Support for xMEMS drivers
• 20,000 mAh battery for 18 hours of battery life
• Fast charging via USB-C

Audio architecture and digital-to-analog conversion

• Quad DAC architecture with four Burr-Brown DSD1793 in hybrid multibit configuration
• DSD1024 remastering via custom FPGA
• JVCKENWOOD K2HD technology
• K2 and K2HD modes for faithful and emotionally engaging sound reproduction
• 6 digital filters for precise sound control: Bit-Perfect, Standard, Minimum, GTO, Apodising, Transient Aligned

Outputs and power

• Headphone output
  • 4.4 mm (balanced)
  • 3.5 mm (S-Bal)
• Line output: 4.4 mm, 3.5 mm, RCA
• Output impedance
  • 4.4 mm: ≤ 0.3 Ω
  • 3.5 mm: ≤ 0.2 Ω
• Output power
  • Up to 2258 mW RMS into 64 Ω
  • Maximum power: 5700 mW

Connectivity and supported formats

• Digital inputs: USB-C, S/PDIF (optical / coaxial), Bluetooth 5.4
• Supported audio formats
  • PCM up to 768 kHz
  • Native DSD512
  • Remastered DSD1024
• Bluetooth codecs: aptX Lossless, aptX Adaptive, LDAC, LHDC / HWA, AAC, SBC
• Lossless Bluetooth for uncompromised listening
• Support for xMEMS drivers for ultra-fast in-ear monitors

Power and battery life

• 20,000 mAh battery (equivalent to electric vehicle batteries)
• Battery life: up to 18 hours
• USB-C PD / QC3.0 20 V fast charging: 2.5 hours
• Battery or mains operation with iPowerX and ANC for ultra-quiet power supply

Processing and features

• Analog processing: XBassII, XSpace, XPresence
• Touch interface with Gorilla Glass
• Solid aluminum buttons
• Control wheel inspired by watch crowns

Construction and design

• CNC-machined aluminum finish
• Retro champagne anodization for timeless aesthetics
• Design inspired by the majestic wings of the Valkyrie and the SR-71 Blackbird
• Premium finish combining aesthetics and ergonomics

Dimensions and weight

• Dimensions: 172 x 160 x 30 mm
• Weight: 882 g

Comparison of iFi portable amplifiers

• iDSD Valkyrie
  • Effective power: 2258 mW
  • DAC: 4x Burr-Brown
  • Bluetooth: aptX Lossless, LDAC, LHDC / HWA
  • Digital filters: 8 (including K2 / K2HD)
• iDSD Diablo 2
  • Effective power: 2060 mW
  • DAC: 2x Burr-Brown
  • Bluetooth: aptX Lossless, LDAC
  • Digital filters: 4
• xDSD Gryphon
  • Effective power: 1000 mW
  • DAC: 1x Burr-Brown
  • Bluetooth: aptX, LDAC
  • Digital filters: 4