Douk Audio E2 Tube Headphone Amplifier Review

The Douk Audio E2 is a tube headphone amplifier and stereo preamp priced at $219.99. It targets headphone enthusiasts who want classic tube character with modern power, wrapped in a chassis that pairs walnut wood panels with an aluminum casing and a retro VU meter.

The heart of the E2 is a German Valvo ECF801 tube operating at an internal voltage of up to 175V - a military-grade tube the maker describes as rare and exceptional - feeding two TPA6120 amplifier chips that deliver up to 2000mW of output. That is enough drive for headphones from 16 to 600 ohms, with 0.55W available in low gain and 2W in high gain. Connection options are broad: a 4-pin XLR jack, a 4.4mm jack and a 6.35mm jack, plus an included 6.35mm to 3.5mm adapter. Frequency response is 20Hz-20kHz within plus or minus 0.5dB, THD+N is 0.02% and SNR is 110dB or better.

As a preamp, the E2 offers two groups of stereo RCA inputs with switchable source selection and a stereo RCA output that can run at the same time as the headphone output, controlled by the same volume and gain setting. The signal path uses a Japanese ALPS potentiometer, German WIMA capacitors and an LME49720 op-amp; only the 49720 sits in a pluggable socket (replaceable with 2604, 2134 or Muse02 among others), while a second NE5532 is fixed. Douk Audio is candid that, due to scarcity, the two square WIMA capacitors are used parts from previous devices. Power it from a DC 15V supply rated at 3A or more, and switch it off before changing op-amps.

Specifications

How it compares

At $219.99 the E2 costs $40.00 more than the Ampapa H1 ($179.99), the other tube amp here with 4-pin XLR, 4.4mm and 6.35mm jacks and RCA preamp outputs. The H1 page rates 4W balanced at 32Ω on high gain and gives three gain steps; the E2 page lists 2W on high gain without naming a load. The H1 runs from DC 12V at 2A or more and carries a pre-sale tag, while the E2 needs DC 15V at 3A or more and shows no such tag. The E2 adds a VU meter and walnut panels; the H1 adds an OLED and a 12V trigger.

Two cheaper routes to balanced output: the Douk Audio P5 is a tube amp with 4.4mm and 6.35mm jacks and an RCA output at $79.99 for the Aluminum Alloy version ($89.99 in Walnut Wood), but its page rates only 200mW at 32Ω. The Douk Audio U5 is $167.00 less at $52.99, with no tube, an XLR input only and 1400mW or more at 32Ω from XLR and 4.4mm outputs. Who it suits: the E2 fits a listener who wants a tube, a VU meter and a preamp feed for speakers and accepts that only one headphone jack works at a time. The H1 suits more drive on balanced cables; the P5 and U5 suit smaller budgets.

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 lists shipping to US, UK, EU, AU and Other (a destination list, with no warehouses named) and shows Free Shipping, 2-8 Days Arrival, 30-Day Return and 2-Year Warranty badges near the price.