Nobsound NS-10P Vacuum Tube Stereo Preamp Review

The Nobsound NS-10P is a mini vacuum tube stereo preamp priced at $49.99. It is the successor to the well-known NS-08E, and its job is to add tube warmth, treble and bass shaping and volume control to sources feeding an existing amplifier or active speakers.

Inside, two 6J1 tubes run in a pure Class A triode circuit on a high-voltage supply, providing 1.5-2.0x voltage amplification. Nobsound describes the result as warm and soft output that adds tube sound and removes the digital edge, suited to vocal, string, soft and classical music. The tube type is rollable if you want to experiment: 6AK5, 6BC5, 403A/B, 5654, EF40, F95 and CV850 are all listed as alternatives to the stock 6J1.

Around the tube stage, the NS-10P offers independent treble, bass and volume controls, an SNR of at least 110dB and a 20Hz-30kHz frequency response. Input and output are standard 3.5mm jacks, so the chain is source (phone, player, CD, DAC or computer) into the NS-10P and out to an amplifier, headphone amp or active speakers. Nobsound specifically points to its TPA3116 amps and NS-08E, NS-01E and NS-02E headphone amps as natural partners. The aluminum shell is CNC-machined with a black and gold finish and a blue tube light, and it weighs just 205g with the tubes fitted.

Specifications

How it compares

The nearest match is the Nobsound TUBE-T4C Stereo Vacuum Tube Preamp review, also $49.99. Both are small tube preamps with independent treble and bass knobs that feed an amplifier or active speakers. The NS-10P page lists 3.5mm in and out, two 6J1 tubes, 1.5-2.0x voltage gain, an independent volume control and SNR of 110dB or better, with a universal AC adapter (100-240V in, DC 6V 2000mA out). The TUBE-T4C page lists RCA in and out, two 6J5 tubes, 2.5x gain and SNR of 100dB, with a DC 5V adapter that must supply 2A or more, in a 78 x 82 x 32mm body at 230g against 105 x 69 x 32 and 205g here. If your amplifier or active speakers take RCA, the T4C needs no adapter cables; the NS-10P suits a headphone amp or a 3.5mm-fed system. Neither page prints test conditions.

The Douk Audio P6 MINI Bluetooth Tube Preamp review ($49.99) costs the same and is the one to look at if you need sources: its page lists Bluetooth 5.0, a U-disk player, an input selector and RCA connections, with distortion of 0.03% or less and SNR of 100dB or better, and one 6A2 tube pair in the box. The NS-10P page prints no distortion figure and has no selector or wireless input. It is the plain option: a tube stage between a source and an amplifier, with volume and tone knobs, for people who already have the sources they need. For a quiet source rather than tone, the Douk Audio L1 MINI Line Level Booster 20dB Preamp review ($39.99) lists up to 20dB of gain where the NS-10P lists 1.5-2.0x.

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.