Douk Audio | Douk Audio P10 PRO HiFi Direct Heated Tube Headphone Amplifier with Long-life Battery Pluaggbel Op-amps Powered by USB-C

FeaturesPortable HiFi Sound: Driven by batteries, P10-PRO features Raytheon JAN6418 direct-heating tubes to deliver rich, warm tube sound. Whether you’re traveling, commuting, or relaxing at home, it pairs effortlessly with your phone, laptop, computers etc. and provides exceptional headphone performance anytime, anywhere.Worry-Free Battery Life: Enjoy up to8-10 hours of uninterrupted music with two600mAh lithium batteries. The P10-PRO supports USB-C charging, allowing you to recharge while listening. When powered off, it fully recharges in just 2.5-3 hours. With the replaceable battery design, you have the option to swap batteries for extended use.Customizable Tubes & Op-Amps: Unlock the true potential of P10-PRO with swappable tubes and op-amps. Start with the original JAN6418 tubes and NE5532 op-amp, then explore upgrades for more possibilities. Enjoy a personalized audiophile experience tailored to your tastes.Visible Top Window: Admire the mesmerizing glow of the JAN6418 tubes through the top window. See the tubes and op-amps in action, adding a touch of style to your audio setup. It not only enhances the aesthetic appeal but also offers insight into the components that shape your premium audio experience.Built for Durability and Convenience: Equipped with WIMA capacitors and a CNC-machined aluminum chassis, the P10-PRO is built to last. Also comes with clear battery status and thoughtful accessories including cables, rubber bands, and a screwdriver—ready for quick setup and hassle-free operation.Q: Why does the P10-PRO make a noise when powered on/off or shocked?A: JAN6418 are directly heated tubes. During power-on/off or physical shock/tap/vibration, a "wing~~~" noise may occur for 25-35 seconds, which is normal and will fade as the tube stabilizes.Q: Why did the battery indicators turn off after I turned the P10-PRO on?A: This is normal. The battery indicators are designed to automatically turn off about 3 seconds after power-on and remain off during use. They will only light up again upon the next power-on. Q: What kind of charger should I use?A: Please use a standard 5V DC power supply. Avoid fast chargers to prevent damage.Q: Can I replace the batteries with different brands or models?A: No. Always use two batteries of the same brand, model, and capacity to avoid malfunctions or safety risks.Q: Is there a temperature requirement for use?A: 8°C to 50°C (46°F to 122°F). Avoid extreme temperatures to ensure proper charging and performance.Q: If I won’t use the P10-PRO for a while, should I remove the batteries?A: Yes.Q: Can I replace the tubes?A: Yes. The default Raytheon JAN6418 tubes can be replaced with CK6418 or CK548DX. Remove glue from the pins before replacement.Q: Can I upgrade the op-amp?A: Yes. The default NE5532 can be upgraded to dual op-amps like JRC4558, JRC4556, OPA2604, OPA2111, or MUSES02.ParametersBrand: NobsoundModel: P10-PROAudio input: 3.5mm AUXAudio output: 3.5mm headphone jackOutput power: 170mW@32ΩFrequency response: 20Hz-20KHz  THD: <0.1%SNR: 75dBGain: 12dBMax. input level: 1.0VrmsMax. output level: 2.5VrmsMatched headphone impedance: 16-200ΩWorking mode: Vacuum tube + Op-amp hybridPower supply: 2 × 14500 Li-ion batteries (3.7V, 600mAh each, total 1200mAh)Battery life: 8–10 hours (varies with volume level used)Battery indicator display: 5-level (0% / 25% / 50% / 75% / 100%)Working temperature: 8-50℃Input voltage: DC 5V/≥1ADimensions (WDH): 1207518mm / 4.722.950.71inPackage dimensions (WDH): 19512065mm / 7.684.722.56inNet weight: 252g / 0.55lbPackage weight: 400g / 0.88lbPacking list1* P10-PRO Headphone Amp1* 3.5mm Cable1* Type-C Cable2* Rubber Band1* Screwdriver1* User Manual