November
2021

Country of Origin

China

Pro iDSD Signature

Reviewer: Srajan Ebaen
Financial interests: click here
Main system: Sources: Retina 5K 27" iMac (4GHz quad-core with Turbo, 32GB RAM, 3TB FusionDrive, OSX Yosemite. iTunes 14.4), PureMusic 3.02, Audirvana 3, Qobuz, Tidal, Denafrips Terminator+ clock-synced to Gaia reclocker, Avatar CD transport, Soundaware D100Pro SD card transport; Preamp: icOn 4Pro SE; Power amplifiers: Kinki Studio EX-B7 monos; Headamp: Kinki Studio; Phones: HifiMan Susvara; Loudspeakers: Aurai Audio Lieutenant, Audio Physic Codex Cube Audio Nenuphar Cables: Complete loom of Allnic Audio ZL; Power delivery: Vibex Granada/Alhambra on all source components, Vibex One 11R on amps, Furutech DPS-4.1 between wall and conditioners; Equipment rack: Artesanía Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc Krion and glass amp stands; Sundry accessories: Acoustic System resonators, LessLoss Firewall for loudspeakers, Furutech NCF Signal Boosters; Room: 6 x 8m with open door behind listening seat
2nd system: Source: Soundaware D300Ref SD transport; DAC: Denafrips Terminator; Preamp/filter: icOn 4Pro + 4th-order/80Hz hi-low pass;
Amplifier: Crayon CFA-1.2; Loudspeakers: sound|kaos Vox 3awf, Dyaudio 18S subwoofer; Power delivery: Furutech GTO 2D NCF; Equipment rack: Hifistay Mythology Transform X-Frame [on extended loan]; Sundry accessories: Audioquest Fog Lifters; Furutech NFC Clear Lines; Room: ~3.5 x 8m
Desktop system: Source: HP Z230 work station Win7/64; USB bridge: Audiobyte Hydra X+; Headamp: COS Engineering H1; Headphones: Final D-8000; Powered speakers: Fram Audio Midi 150
Upstairs headfi/speaker system: Source: Soundaware A280 SD transport; Integrated amplifiers: Schiit Jotunheim R, Bakoon AMP-13R; Phones: Raal-Requisite SR1a; Loudspeakers: Acelec Model 1, Power delivery: Furutech GTO 2D NCF
2-channel video system: Source: Oppo BDP-105; All-in-One: Simon Audio AIO; Loudspeakers: German Physiks HRS-120 + Zu Submission; Power delivery: Furutech eTP-8, Room: ~6x4m

Review component retail: $/€3'249

Billy's a heavy. He gets invited only to the most exclusive of parties. He's a recluse really. Bob's hip and budgetarian. His social circulation is vast, his name on everyone's lips. Hello Abbingdon Music Research. Yo iFi. They're two brothers from the same company mother. Even the engineering father Thorsten Loesch is the same. Now the Pro iDSD Signature for iFi is his newest valve/trans DAC/pre whose fully balanced class A output stage of 11.7V/4-watt can drive many a headphone directly. It's a flagship packed to the gills with AMR's best tech. Now Billy Bob's your uncle.

For the in 'n' outs, refer to iFi's videos. The internal converter engine of four Burr Brown DACs runs parallel/interleaved. That mimics an 8-bit/multi-bit hybrid. "A multi-bit architecture handles our top bits. Since ΔΣ modulators struggle at high levels, we removed their main disadvantage and need for high-order modulators. Multi-bit systems have the opposite problem. They aren't very good at very low levels. By splitting low-level signals off into a low-order ΔΣ modulator, we get the best of both worlds."

Via a very powerful FPGA, we can resample PCM to DSD512/1024 on the fly should we choose. More choices come with MQA, five selectable digital filters, three gain settings for headfi and two bypassable NOS GE5670 tubes. If we fire those up in lieu of the input Jfets, we can even adjust their negative feedback for more or less 2nd-order THD. Also included is a metal IR remote and the company's €299 60-watt iPower Elite external power supply with a claimed sub 1µV noise floor. There's even an SDHC micro memory card slot in the back whose contents are navigated with the free WiiM Player.

If Billy Bob had words, he'd say hubba hubba. As is, he's quite speechless.

At €3'249, he obviously rides in on a higher horse than iFi's entry-level models. But he does give Thorsten Loesch a platform to pile on his know-how and run the premium parts this Signature version wanted; like a motorized six-gang Alps pot, audio-grade Elna Silmic and Dynacaps, OsCon and MuRata parts.

Here's an overview on parts envy. GMT isn't Greenwich Mean Time but Global Master Timing. In short, that's Thorsten speak for using the same low-jitter clock for his memory buffer, X-Core 200 USB transceiver and Crysopeia FPGA. Linkplay WiFi/network playback offers "built-in Spotify and Tidal so the Pro iDSD Signature can be used without a computer to stream audio directly". That makes this machine a streamer, preamp, head amp and DAC so 4-in-1.