The FiiO Darkside Pro is a regulated low-noise linear power supply with a 75W toroidal transformer, switchable 12/15V output and up to 3A. Ideal for the FiiO K13 R2R, K11 R2R, DACs, streamers and other compatible audio gear. Read more.
The FiiO Darkside Pro is a regulated low-noise linear power supply designed for audio equipment requiring 12V or 15V DC. Its audiophile-grade 75W toroidal transformer, fully discrete NMOS voltage regulation and output current of up to 3A provide a stable power source for compatible DACs, streamers, headphone amplifiers and other hi-fi components.
Within the FiiO range, the Darkside Pro offers a premium power solution for demanding desktop and hi-fi systems.
At the heart of the Darkside Pro is an audiophile-grade 75W toroidal transformer with a grain-oriented silicon-steel core, designed for efficient operation and low magnetic leakage.
FiiO combines this with fully discrete NMOS voltage regulation and two parallel IRFZ34NPBF MOSFETs. High-quality ELNA, Rubycon and WIMA components are complemented by a Shindengen bridge rectifier and silver-plated monocrystalline copper internal DC wiring.
The Darkside Pro features a robust GX16-2 DC output. A dedicated switch selects either 12V or 15V, with a maximum output current of 3A.
An integrated relay manages the transformer output according to the selected voltage. The precision potentiometer is intended for minor voltage correction and calibration; it is not a freely adjustable output control operating in 0.1V steps.
FiiO officially lists both the FiiO K13 R2R and FiiO K11 R2R as compatible devices. The Darkside Pro is especially attractive alongside the K13 R2R because both products share a closely matched desktop design language.
Other officially listed compatible models include the K11, K15, K19, R7, R9, TT13, K5 Pro series, K7 series and Q7. Compatible FiiO portable players using USB-C power can also be supported with the appropriate separately available DC-to-USB-C adapter.
The Darkside Pro is not limited to FiiO products. Equipment from other manufacturers can also be powered when it requires 12V or 15V DC, draws no more than 3A and has the correct connector, polarity and electrical requirements.
Always verify voltage, current requirements, connector and polarity before connecting any device.
A high-quality linear power supply is designed to provide sensitive audio electronics with stable DC power and very low supply noise. This can be particularly relevant for DACs, streamers, headphone amplifiers and other components where clean power is an important part of the overall electrical design.
Any audible difference will depend on the connected product, its original power supply, mains conditions and the complete audio system. The Darkside Pro should therefore primarily be regarded as a high-quality technical power upgrade rather than a guarantee of a specific sonic change.
Explore our complete range of audio power supplies and linear PSUs.
The substantial unibody aluminium enclosure provides mechanical stability and helps shield the circuitry from electromagnetic interference. Ventilation openings assist with dissipating the heat naturally generated by a powerful linear power supply.
Always use the Darkside Pro in a cool, well-ventilated location. Keep all ventilation openings unobstructed and do not cover the unit during operation.
| Type | Regulated low-noise linear power supply |
| Transformer | 75W audiophile-grade toroidal transformer |
| Transformer core | Grain-oriented silicon steel |
| DC output voltage | 12V or 15V, relay-switched |
| Output current | 0–3A |
| DC output | GX16-2 aviation socket |
| Voltage regulation | Fully discrete NMOS regulation with parallel dual-MOSFET output |
| MOSFETs | 2 × IRFZ34NPBF |
| Capacitors | ELNA, Rubycon and WIMA |
| Bridge rectifier | Shindengen D15XB60 series |
| Internal DC wiring | Silver-plated monocrystalline copper |
| Output noise | ≤17 µVrms at 12V / ≤30 µVrms at 15V, A-weighted |
| Fine adjustment | Precision potentiometer for minor correction/calibration |
| Overcurrent protection | Self-resetting protection |
| AC input | 220–240V or 100–120V, 50/60Hz; input version is not switchable |
| Dimensions | 188 × 188 × 42.3 mm |
| Weight | Approx. 2.2 kg |
| Colours | Black and silver |
Yes. FiiO officially lists the K13 R2R as compatible, and both products also share a complementary desktop design.
No. Users select either 12V or 15V. The precision potentiometer is intended for minor correction and calibration of the output voltage.
Yes, provided the device requires 12V or 15V DC, draws no more than 3A and uses the correct connector, polarity and electrical specifications.
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