{"product_id":"yulong-a39-desktop-headphone-amplifier","title":"YULONG DAART A39 Desktop R2R Pre-Amp \u0026 Headphone Amplifier","description":"\u003ch1\u003e\n \u003cstrong\u003eA compact powerhouse with serious control\u003c\/strong\u003e\u003cbr\u003e\n \u003c\/h1\u003e\n \u003cp\u003eThe Yulong A39 is a Class-A headphone amplifier and reference-grade preamp that blends sophisticated tech with warm, dynamic sound. Designed to handle everything from high-impedance over-ears to sensitive IEMs, it delivers 6W of Class-A balanced power and 99-step R2R volume control in a compact, CNC-machined aluminum chassis. Paired with its retro VU meters and IPS display, it brings the brains, the brawn, and a little bit of nostalgia to your desk.\u003c\/p\u003e\n \u003ch2\u003e\u003cstrong\u003eClass-A power—without the heatstroke\u003c\/strong\u003e\u003c\/h2\u003e\n \u003cp\u003eAt the heart of the A39 is a 6W constant-current Class-A amplifier, built from discrete components and driven by 16 medium-power transistors. This means rich harmonics, low distortion (0.0002%), and serious drive—without needing a fan or a fire extinguisher. The all-aluminum case pulls double duty as a heatsink, keeping things cool even when the evening gets away from you.\u003c\/p\u003e\n \u003ch2\u003e\u003cstrong\u003eReal-time monitoring and protection\u003c\/strong\u003e\u003c\/h2\u003e\n \u003cp\u003eUnder the hood, a CPU running a custom Linux system manages thermal conditions, overcurrent protection, voltage, and startup sequences. So even if you’re swapping headphones mid-session or pushing power-hungry cans, the A39 keeps everything running safely and quietly.\u003c\/p\u003e\n \u003ch2\u003e\u003cstrong\u003eVolume that doesn’t suck (your tone away)\u003c\/strong\u003e\u003c\/h2\u003e\n \u003cp\u003eTraditional volume pots introduce noise and lose detail. The A39 uses a CPU-controlled relay system paired with an R2R resistor ladder, giving you 99 steps of transparent, lossless attenuation. The relay locks in a closed loop, eliminating electromagnetic interference, while the R2R network keeps the signal pure.\u003c\/p\u003e\n \u003ch2\u003e\u003cstrong\u003eBuilt to pair with the D39 DAC\u003c\/strong\u003e\u003c\/h2\u003e\n \u003cp\u003eThe A39 is designed to visually and functionally pair with Yulong’s D39 streaming DAC. Together, they form a full desktop control center—small enough to fit on an A4 sheet, powerful enough to anchor your entire system.\u003c\/p\u003e\n \u003ch2\u003e\u003cstrong\u003eLooks smart, acts smarter\u003c\/strong\u003e\u003c\/h2\u003e\n \u003cp\u003eThe IPS LCD screen shows dynamic spectrums and classic VU meters—one eye on nostalgia, the other on precision. The intuitive knob or included remote make adjustments easy. \u003c\/p\u003e\n \u003ch2\u003e\u003cstrong\u003eA power supply that doesn’t cut corners\u003c\/strong\u003e\u003c\/h2\u003e\n \u003cp\u003eInside is a custom 50W NORATEL toroidal transformer with linear regulation. It feeds clean, consistent power to the amp and preamp stages, contributing to the low noise floor and stable operation. \u003c\/p\u003e\n \u003ch3\u003e\u003cstrong\u003eProduct highlights\u003c\/strong\u003e\u003c\/h3\u003e\n \u003cul\u003e\n \u003cli\u003eConstant-current Class-A discrete headphone amplifier with 6W balanced output\u003c\/li\u003e\n \u003cli\u003eFPGA-controlled R2R resistor network with relay switching for 99-step volume control\u003c\/li\u003e\n \u003cli\u003eCPU monitoring for voltage, current, temperature, delayed startup, and shutdown\u003c\/li\u003e\n \u003cli\u003e50W custom NORATEL toroidal transformer with linear power regulation\u003c\/li\u003e\n \u003cli\u003eBalanced (XLR\/4.4mm) and single-ended (6.35mm) headphone outputs\u003c\/li\u003e\n \u003cli\u003eBalanced (XLR) and single-ended (RCA) preamp inputs and outputs\u003c\/li\u003e\n \u003cli\u003eIPS LCD screen with real-time spectrum analyzer and retro VU meters\u003c\/li\u003e\n \u003cli\u003eRemote control and single-knob operation\u003c\/li\u003e\n \u003cli\u003eImpedance switching for headphone output\u003c\/li\u003e\n \u003cli\u003eAll-aluminum CNC chassis for passive heat dissipation\u003c\/li\u003e\n \u003cli\u003eDesigned to match the Yulong D39 streaming DAC\u003c\/li\u003e\n \u003cli\u003eUSB DFU port for firmware and software updates\u003c\/li\u003e\n \u003cli\u003eCompact A4-sized footprint for desktop use\u003c\/li\u003e\n \u003cli\u003eGlobal voltage switch for international use\u003c\/li\u003e\n \u003c\/ul\u003e\n \u003ch3\u003e\u003cstrong\u003eSpecs\u003c\/strong\u003e\u003c\/h3\u003e\n \u003cul\u003e\n \u003cli\u003eHeadphone output power (single-ended):\n \u003cul\u003e\n \u003cli\u003e32Ω: 2500mW\u003c\/li\u003e\n \u003cli\u003e64Ω: 2200mW\u003c\/li\u003e\n \u003cli\u003e150Ω: 1000mW\u003c\/li\u003e\n \u003cli\u003e300Ω: 500mW\u003c\/li\u003e\n \u003cli\u003e600Ω: 250mW\u003c\/li\u003e\n \u003c\/ul\u003e\n \u003c\/li\u003e\n \u003cli\u003eHeadphone output power (balanced):\n \u003cul\u003e\n \u003cli\u003e32Ω: 6000mW\u003c\/li\u003e\n \u003cli\u003e64Ω: 6000mW\u003c\/li\u003e\n \u003cli\u003e150Ω: 3200mW\u003c\/li\u003e\n \u003cli\u003e300Ω: 1800mW\u003c\/li\u003e\n \u003cli\u003e600Ω: 900mW\u003c\/li\u003e\n \u003c\/ul\u003e\n \u003c\/li\u003e\n \u003cli\u003eTHD+N: 0.0002%\u003c\/li\u003e\n \u003cli\u003eSNR: \u0026gt;120dB\u003c\/li\u003e\n \u003cli\u003eCrosstalk: \u0026lt;-100dB\u003c\/li\u003e\n \u003cli\u003eFrequency response: 20Hz–30kHz ±0.15dB\u003c\/li\u003e\n \u003cli\u003ePreamp input impedance: 10kΩ\u003c\/li\u003e\n \u003cli\u003ePreamp output impedance: 200Ω\u003c\/li\u003e\n \u003cli\u003ePreamp output level:\n \u003cul\u003e\n \u003cli\u003eRCA: 1.00V\u003c\/li\u003e\n \u003cli\u003eXLR: 2.05V\u003c\/li\u003e\n \u003c\/ul\u003e\n \u003c\/li\u003e\n \u003cli\u003ePower consumption: \u0026lt;50W\u003c\/li\u003e\n \u003cli\u003eDimensions: 9.8in x 8.3in x 2.4in (248mm x 210mm x 60mm)\u003c\/li\u003e\n \u003cli\u003eWeight: 5.7lbs (2.6kg)\u003c\/li\u003e\n \u003c\/ul\u003e","brand":"Yulong","offers":[{"title":"Black","offer_id":46866225791151,"sku":"APS-1013-1","price":1099.0,"currency_code":"USD","in_stock":true},{"title":"Silver","offer_id":46866225823919,"sku":"APS-1013-2","price":1099.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0734\/6415\/2239\/files\/apos-audio-xduoo-dac-digital-to-analog-converter-yulong-daart-a39-desktop-r2r-pre-amp-headphone-amplifier-1154368343.jpg?v=1777716407","url":"https:\/\/freshized.com\/products\/yulong-a39-desktop-headphone-amplifier","provider":"Freshized","version":"1.0","type":"link"}