{"type":"firestarter.listing","listing":{"id":"lst_03o7Ef4i","product_name":"SMSL H400 High-End Fully Balanced Headphone Amplifier Silver","category":"Headphone Amp","description":"The SMSL H400 High-End Headphone Amplifier is a premium desktop headphone amplifier designed for audiophiles who want powerful output, clean sound, and precise audio performance. Built with a fully balanced design, the H400 delivers excellent channel separation, low noise, and strong driving capability for a wide range of headphones.\nWith a wide frequency response of 20Hz to 100kHz (-0.5dB), the H400 is designed to reproduce audio with clarity, detail, and accuracy. Its high-end amplifier design makes it suitable for demanding headphones, desktop HiFi systems, and dedicated headphone listening setups.\nThe included remote control adds convenient operation, while the silver finish gives the unit a clean and premium desktop appearance. This item is in open box condition.\nKey Features:\n\n\nSMSL H400 high-end headphone amplifier\n\n\nFully balanced amplifier design\n\n\nWide frequency response: 20Hz to 100kHz (-0.5dB)\n\n\nPowerful and clean headphone output\n\n\nLow-noise performance with strong detail\n\n\nSuitable for desktop HiFi and audiophile headphones\n\n\nIncludes a remote control\n\n\nSilver color\n\n","images":["https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-addsoap-headphone-amp-smsl-h400-high-end-fully-balanced-headphone-amplifier-silver-1248568829.jpg?v=1783781890","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-addsoap-headphone-amp-smsl-h400-high-end-fully-balanced-headphone-amplifier-silver-1248568827.jpg?v=1783787649","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-addsoap-headphone-amp-smsl-h400-high-end-fully-balanced-headphone-amplifier-silver-1248568828.jpg?v=1783787708","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-addsoap-headphone-amp-smsl-h400-high-end-fully-balanced-headphone-amplifier-silver-1248568826.jpg?v=1783787769"],"price":433.5,"currency":"USD","in_stock":true,"inventory_qty":9999,"dynamic_pricing":false,"listed_at":"2026-06-20T16:25:55.026Z","product_rating":null,"product_rating_count":0,"seller_rating":null,"seller_rating_count":0,"units_sold":0,"reviews":{"count":0,"top":[]},"videos":[]},"share_url":"https://firestarter.network/l/lst_03o7Ef4i","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_03o7Ef4i' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy SMSL H400 High-End Fully Balanced Headphone Amplifier Silver' and a budget_max comfortably above $433.50 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."]}}