Douk Audio P1 PLUS Bluetooth Tube Preamp Review

The Douk Audio P1 PLUS is a desktop audio hub priced at $189.99 that bundles four devices into one chassis: a Bluetooth receiver, a USB DAC, a tube preamp and a headphone amplifier. It wears vintage looks - customized pluggable VU meters, retro military-grade vacuum tubes and a clear OLED screen - over a CNC-molded aluminum body.

On the digital side, a QCC5125 Bluetooth chip supports aptX-HD and LDAC for wireless streaming up to 24-bit/96kHz, while the SA9137L USB chip and ESS9018K2M DAC handle PCM data up to 384kHz/32-bit and DSD256 over USB. The coaxial and optical inputs top out at PCM 192kHz/24-bit, and one handy extra: the P1 PLUS can act as a USB-to-optical converter, since the optical output works whenever the PC-USB input is active. The TPA6120 headphone amp chip powers headphones from 16 to 600 ohms.

The tube preamp stage elevates voltage to 100V so the vacuum tubes operate at their full potential, delivering what the maker calls crisp highs, lush mids and deep bass; the tube sockets are pluggable for tube rolling. Connectivity is extensive - Bluetooth, USB, coaxial, optical, stereo RCA and 3.5mm AUX in; optical, stereo RCA, 3.5mm AUX and 3.5mm headphone out - with tone knobs for bass and treble and a remote control that includes a Bluetooth reset button. Two behaviors to note: every analog output plays simultaneously regardless of the selected input, and the in-circuit OPA1656 plus two pluggable NE5532 op-amps offer further tuning options.

Specifications

How it compares

The nearest rival is the Douk Audio DAC-T1 PRO Tube Stereo Preamp review ($169.99), which is $20.00 cheaper and also pairs Bluetooth, a USB DAC, a headphone amp, an OLED screen and JAN5654 tubes. The P1 PLUS page lists the higher resolution (PCM 384KHz/32Bit and DSD256 over USB against 24bit/192KHz), the stronger headphone stage (up to 750mW with a 16-600Ω matched range against 150mW and 16-300Ω) and extras the DAC-T1 PRO page does not: pluggable VU meters, an optical output and a 3.5mm AUX input. The DAC-T1 PRO page prints the better distortion and noise figures (THD 0.08% against 0.1%, SNR 110dB or better against 106dB or better) and a tighter frequency-response tolerance (±0.5dB against ±1.8dB), with no test conditions on either page. The P1 PLUS suits listeners with demanding headphones or high-rate USB files; the DAC-T1 PRO suits those who weigh the printed THD and noise figures more and want the bypass its page describes for comparing digital and tube sound.

For less money, the Douk Audio P1 Bluetooth Tube Preamp USB DAC review ($89.99) is $100.00 below and keeps Bluetooth, PC-USB, a tube stage and a headphone amp (160mW into 32Ω for 32-300Ω headphones), but its page lists only Bluetooth, PC-USB and RCA inputs, with no optical or coaxial input and no VU meter. For a different job, the Douk Audio TUBE-T5C 4-Way Tube Preamp review ($109.99) has no DAC and no Bluetooth: its page lists four RCA inputs, two RCA outputs, up to 500mW into 32Ω for 16-600Ω headphones and a VU meter, with THD+N of 0.06% and SNR of 107dB or better. Choose the P1 PLUS to replace a DAC, a Bluetooth receiver and a headphone amp with one box, the TUBE-T5C to switch several analog sources, and the P1 if Bluetooth, USB and RCA are all you plug in.

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 has a 'Shipping to' selector (US, UK, EU, AU, Other) and shows Free Shipping, 2-8 Days Arrival, 30-Day Return and 2-Year Warranty badges near the price; the store's option data prices 'Other' at $199.99 against $189.99 for the other four.