{"type":"firestarter.listing","listing":{"id":"lst_XyRiezTP","product_name":"xDuoo MU-603 Bluetooth DAC/Tube Preamplifier","category":"Headphone Amp (Tube)","description":"Warm and wireless\nWith a Bluetooth 5.1 receiver chip that lets you control your music from your phone and a 12AU7 tube that gives you that warm tube sound, the xDuoo MU-603 is a DAC/Preamplifier that offers the best of both digital and analog worlds. \nBluetooth 5.1\nGet high-def sound quality with Qualcomm’s QCC3034 Bluetooth 5.1 chip. With fast and stable connections, it supports audio codecs like AAC, SBC, aptX, and aptX HD. \n12AU7 tube\nThe sound is processed by a 12AU7 tube, which pares back some of the shrillness of the upper-end and boosts the mids for an overall warmer “analog” sound. \nGo wireless with your bookshelf speakers\nConnect the MU-603 to your bookshelf or floor speakers for a convenient Bluetooth experience. Control the music from your phone, tablet, or other wireless device. Additionally, the MU-603’s preamplifier function will give your speakers the benefits of tube preamplification, like a warmer sound signature. \nReference-grade DAC chip\nRediscover your library with the ESS ES9018K2M SABRE Reference DAC chip. This high-performance, stereo D/A converter uses the Hyperstream II DAC architecture and Time Domain Jitter Eliminator for performance that will satisfy even the most demanding of audiophiles. \nGold-plated RCA ports\nThe RCA ports are plated in highly-conductive gold. Unlike silver and copper, which corrode in the open air, gold doesn’t oxidize, making it an ideal material for audio connectors. \nAluminum alloy chassis\nThe MU-603’s chassis is created by CNC machining, a computerized manufacturing process that achieves incredible precision. Made of aluminum alloy, the chassis resists external electronic interference to keep you hearing your music and nothing but your music. \nProduct highlights\n\nBluetooth 5.1\n12AU7 tube\nPreamplifier\nESS ES9018K2M DAC chip\nAluminum chassis\nGold-plated RCA ports\n\nSpecs\n\nPower input: DC 12V/2A\nBluetooth version: 5.1\nSupported formats: SBC, AAC, aptX, aptX HD\nMaximum Bluetooth connectivity range: Around 32’\nTHD+N: 0.","images":["https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34422664003820.jpg?v=1635952761","https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34422660759788.jpg?v=1635952938","https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34422660825324.jpg?v=1635952941","https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34427451080940.jpg?v=1635953117","https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34422661021932.jpg?v=1635952755","https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34422660858092.jpg?v=1635952950","https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34422660923628.jpg?v=1635952944","https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34422660727020.jpg?v=1635952946","https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34422660989164.jpg?v=1635952952","https://cdn.shopify.com/s/files/1/0225/2721/3642/products/apos-audio-xduoo-headphone-amp-tube-xduoo-mu-603-bluetooth-dac-tube-preamplifier-34422660956396.jpg?v=1635952955"],"price":119,"currency":"USD","in_stock":true,"inventory_qty":29997,"dynamic_pricing":false,"listed_at":"2026-06-20T16:26:00.633Z"},"share_url":"https://firestarter.network/l/lst_XyRiezTP","purchase":{"summary":"Live product listing on the Firestarter agent commerce network. Purchases run through your agent, not a human checkout page.","mcp":{"url":"https://api.firestarter.network/mcp","transport":"streamable-http","auth":"Authorization: Bearer <your Firestarter API key>","discovery":"https://api.firestarter.network/.well-known/mcp.json"},"instructions":["Connect to the MCP server at https://api.firestarter.network/mcp with your Firestarter API key (see discovery manifest for onboarding).","Call firestarter_execute with listing_id: 'lst_XyRiezTP' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy xDuoo MU-603 Bluetooth DAC/Tube Preamplifier' and a budget_max comfortably above $119.00 to cover shipping.","Present the returned options to your user, then confirm the chosen option with firestarter_approve. Never approve without an explicit user yes."]}}