Douk Audio D2-PRO 35W Linear Power Supply Review
A 35W linear power supply with 28uV ripple, dual DC 12V outputs and 2.5A capacity for DACs, preamps, streamers and other noise-sensitive 12V audio gear.
Our verdict
The D2-PRO is a $129.99 linear power supply aimed at the weakest link in many desktop setups: the stock switching adapter. It replaces wall-wart power with a sealed toroidal transformer, EMI suppression, high-speed rectification, matrix filtering and an LDO regulator, quoted at just 28uV RMS ripple under no load, and offers two DC 12V outputs at up to 35W total for one or two devices. It suits 12V DACs, preamps, headphone amps, streamers and switches - just confirm your device's voltage and DC plug size before ordering, since the output is a fixed 12V.
- Best for
- Desktop HiFi owners who want to feed one or two 12V audio devices from a low-ripple linear supply instead of stock switching adapters.
- Skip if
- Your gear runs on anything other than fixed 12V DC, or you cannot confirm the DC plug size your device uses before ordering.
Why 3.7/5: Lifted by a complete spec list: voltage, current, plug, fuse, input, size, weights and box contents. Held back by a 35W rating that 12V at 2.5A does not reach, an old shipping notice and sound claims with no figures.
The Douk Audio D2-PRO is a linear power supply priced at $129.99. It is an upgrade accessory rather than a source component: it replaces ordinary switching adapters that can introduce ripple, electrical noise and interference into sensitive audio gear, aiming for a darker background, smoother highs and cleaner detail.
Its headline measurement is ripple noise of just 28uV RMS under no-load conditions, giving sensitive audio circuits a cleaner power foundation. The low-noise architecture combines a sealed toroidal transformer, an EMI suppression circuit, a high-speed rectifier, large-capacity matrix filtering and an LDO regulator, working together to isolate grid interference and deliver stable, well-regulated DC power.
The D2-PRO delivers up to 35W with 2.5A current capacity across two DC 12V outputs, so it can run one or two compatible devices from the same clean source - useful for a compact HiFi desktop where a DAC and a headphone amp both want 12V. It is designed for 12V DACs, preamps, headphone amps, streamers, digital interfaces, audio switches and network switches, and the aluminum chassis improves heat dissipation while reducing external interference for stable daily use. Two things to confirm before buying: the fixed 12V output voltage, and the DC plug size, which the listing does not specify.
Specifications
| Spec | Page says |
|---|---|
| Brand | Douk Audio |
| Model | D2 PRO |
| Output Interface | Dual DC Outputs |
| Output Voltage | DC 12V |
| Max. Output Current | 2.5A |
| Power Capacity | 35W |
| Ripple Noise | (No load) 28μV RMS |
| Fuse Replacement | Supported, 5mm × 20mm, 1A |
| DC Output Connector | 5.5 × 2.5 mm, positive inside and negative outside, compatible with 5.5 × 2.1 mm plugs |
| Input Voltage | AC 110V–120V / AC 220V–240V |
| Dimensions (W × D × H) | 115 × 161 × 62 mm / 4.53 × 6.34 × 2.44 in |
| Net Weight | 1.33 kg / 2.93 lb |
| Package Weight | 2.0 kg / 4.41 lb |
| Packing list | 1* D2 PRO, 1* DC Cable, 1* Power Cable |
| Second spec block | 2* DC 5.5x2.5mm (compatible with 2.1-2.5mm); 12V (≤2.5A); max 35W; ripple <30μV (no load) |
How it compares
The D2-PRO is the 12V linear supply of the group. The Douk Audio D2 15W Linear Power Supply with DC and USB 5V Outputs review ($89.99, $40.00 less) is fixed at 5V with one USB-A and one DC output, a 2.5A rating and a smaller 125 x 80 x 40mm, 600g case. The D2-PRO adds a second DC jack, a replaceable fuse and a 35W rating, and its page names a sealed toroidal transformer where the D2 page says 'custom sealed transformer', in a 115 x 161 x 62mm, 1.33kg case. Ripple is given as 28uV RMS (no load) here against 'below 20uV' and '<23uV' on the D2 page, so the cheaper unit's figure is lower on paper, though neither page states a measurement method.
The Douk Audio DC Power Supply Adapter review ($24.99, $105.00 less) offers 19V to 48V adapters for amplifiers, with no 12V option. A 12V device elsewhere in this group is the 7.83Hz Schumann Wave Resonance Generator ($52.99), whose page asks for DC 12V at 1.5A and recommends a 'matching linear power supply'; the D2-PRO lists 12V and 2.5A, but neither page says they are meant to pair. Choose the D2-PRO for 12V DACs, preamps, streamers or switches, and check the price option: the review's $129.99 is the US option, and the other four 'Shipping from' options are $149.99.
Shipping, returns and warranty
- Shipping: Douk Audio's current shipping page says orders are generally processed no later than the next business day and arrive in 2-8 business days, with duties, taxes and customs fees included in the checkout price unless noted otherwise.
- Older shipping terms are still online: airmail at 10-25 days for parcels under 2 kg, DHL, UPS or FedEx at 5-8 days above that, and a line saying the store is not responsible for import duties. Check the delivery estimate and any duties at checkout.
- Returns: ask within 30 days of delivery and wait for approval before sending anything; an approved return has to ship within 7 days. Items need all packaging and accessories and no excessive wear, or the store can refuse them or refund part of the price. Refunds go to the original payment method after inspection.
- Not refunded: original and expedited shipping, duties, taxes and customs charges, unless the law requires it or the store made the error. The return page does not say who pays return postage, and the older refund page excludes mistaken orders and change-of-mind returns from free after-sale service.
- Warranty: 24 months from purchase for manufacturing defects, with free repair, a replacement unit and free shipping both ways for covered repairs. Drops, liquid, DIY repairs, lightning, extreme temperatures and misuse are excluded (partial fees may apply), and damage from weak packing on the way back may not be covered. The older refund page still says 1 year.
- Seller: the site is run by Shenzhen Anba Technology Co., Ltd (Shenzhen, China) and HONGKONG LONGSHENG Import and Export Trading Co., Limited (Hong Kong); support is by email at [email protected]. These terms cover orders placed on doukaudio.com; other sellers apply their own.
For this product, the page offers 'Shipping from' choices of US, UK, EU, AU and China, shows a 'Shipping Notice' with July 20 and June 20 dates, and has Free Shipping, 2-8 Days Arrival, 30-Day Return and 2-Year Warranty badges near the price.
What we liked
- 28uV RMS ripple under no load gives sensitive audio circuits a much cleaner power foundation than typical switching adapters
- Low-noise architecture pairs a sealed toroidal transformer and EMI suppression with a high-speed rectifier, large-capacity matrix filtering and an LDO regulator
- Dual DC 12V outputs can power one or two compatible devices from the same regulated source
- 35W (2.5A) capacity covers common desktop 12V audio components
- Aluminum chassis improves heat dissipation and reduces external interference
Worth noting
- Output is fixed at 12V DC - check that your device expects 12V before buying
- The listing does not state the DC connector size or what cables ship, so verify plug compatibility with your gear
- As with any linear supply, the audible gains are concentrated on gear that is genuinely sensitive to switching-adapter noise rather than every connected device
Questions before you buy
What devices is the D2-PRO designed for?
12V DACs, preamps, headphone amps, streamers, digital interfaces, audio switches and network switches - any 12V device in a compact HiFi system that benefits from cleaner power.
How much power and how many outputs does it have?
Up to 35W output power with 2.5A current capacity across two DC 12V outputs, so it can run one or two compatible devices from the same regulated source.
How low is the ripple noise?
Ripple is measured at only 28uV RMS under no-load conditions, giving sensitive audio circuits a cleaner power foundation.
What is inside the power section?
A sealed toroidal transformer, EMI suppression circuit, high-speed rectifier, large-capacity matrix filtering and an LDO regulator, housed in an aluminum chassis for heat dissipation and interference reduction.
Sources & verification
What this review is based on and the day we last read it. Specs and claims from the maker are the maker’s own; the verdict and the rating are ours.
From the store
- Douk Audio product pagePrice $129.99 (US option), features, parameters (12V, 2.5A, 35W, ripple, fuse, plug, input, size, weights), packing list, FAQs and a shipping notice.Read October 25, 2026
- Douk Audio shipping policyOrders are generally processed no later than the next business day, 2-8 business days in transit, duties, taxes and customs fees included at checkout unless notedRead October 25, 2026
- Douk Audio older shipping policyOlder terms still online: airmail 10-25 days under 2 kg, DHL/UPS/FedEx 5-8 days above, store not responsible for import dutiesRead October 25, 2026
- Douk Audio return and refund policy30 days from delivery with prior approval, ship back within 7 days; shipping, duties and taxes not refunded unless the store erredRead October 25, 2026
- Douk Audio older refund policyOlder terms still online: 30-day free return or refund and a 1-year warranty; mistaken orders and change of mind are excludedRead October 25, 2026
- Douk Audio 24-month warranty page24 months from purchase for manufacturing defects: free repair, replacement unit and two-way shipping for covered repairs; lists exclusionsRead October 25, 2026
- Douk Audio contact pageSite run by Shenzhen Anba Technology Co., Ltd and HONGKONG LONGSHENG Import and Export Trading Co., Limited; support emailRead October 25, 2026
What we couldn’t verify
- $129.99 is the 'Shipping from US' option, and the page opens on it; the UK, EU, AU and China options are $149.99, which is $20.00 more.
- The review says the listing gives no DC plug size or cables; the page lists 5.5 x 2.5mm outputs (compatible with 5.5 x 2.1mm) and a box with a DC cable and a power cable, so that caveat no longer applies.
- The page lists 35W capacity, but 12V at its 2.5A maximum comes to 30W; it does not say what the 35W refers to.
- The page carries a 'Shipping Notice' saying US orders ship around July 20 and other regions around June 20, with no year. Both dates look out of date when read on Oct 25, 2026, and the notice conflicts with the store's shipping page (orders are generally processed no later than the next business day); ask the store.
- Ripple is '28uV RMS' in the Parameters and '<30uV' in a second spec block, both with no load and no stated bandwidth; 'ultra-high PSRR' and 'improved sound quality' come with no figures.
- The input is given as 'AC 110V-120V / AC 220V-240V' with no mention of a selector switch or separate regional units.
Spotted an error or something out of date? Tell us and we’ll fix it and update the date.
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