{"type":"firestarter.listing","listing":{"id":"lst_Vs3XQtFC","product_name":"Cayin RU7 1-Bit Resistor Network Portable DAC","category":"DAC (Digital-to-Analog Converter)","description":"Cayin RU7 discrete 1-bit dongle DAC\nThe Cayin RU7 is an ultra-portable USB-C dongle DAC built around a fully discrete 1-bit resistor network. It combines native DSD decoding, balanced and single-ended headphone outputs, and a hardware resistor ladder volume control in a compact metal chassis. Designed for phones, tablets, and computers, the RU7 delivers precise digital-to-analog conversion without relying on an integrated DAC chip.\nDiscrete 1-bit resistor ladder DAC\nThe RU7 uses a fully-balanced discrete 1-bit DAC built from 128 high-precision thin-film resistors rather than an off-the-shelf DAC chip. Incoming audio is converted to a DSD bitstream and processed through four parallel 1-bit DAC channels. This architecture prioritizes timing accuracy and low noise, helping preserve fine detail and stable channel balance during playback.\nUser-selectable all-to-DSD processing\nAll incoming digital audio can be converted to DSD64, DSD128, or DSD256 before reaching the DAC stage. PCM is supported up to 384 kHz, and native DSD is supported from DSD64 through DSD256. Converting everything to a single format simplifies signal handling and allows the discrete DAC stage to operate under consistent conditions.\nParallel balanced headphone amplification\nThe headphone amplifier stage uses dual amplifiers in parallel to deliver higher current and improved control. The 4.4mm balanced output provides up to 400 mW into 32 ohms, while the 3.5mm single-ended output delivers up to 160 mW into 32 ohms. This allows the RU7 to comfortably drive sensitive IEMs as well as many full-size headphones.\nShared headphone and line output\nBoth the 3.5mm and 4.4mm outputs can be switched between headphone output and fixed-level line output. Line output bypasses the volume control and provides 1.2 Vrms from the 3.5mm jack and 2.4 Vrms from the 4.4mm jack. This makes it easy to use RU7 as a compact DAC feeding a portable amp, desktop amp, or home audio system.\nDiscrete resistor ladder volume control\nInste","images":["https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344890.jpg?v=1768862048","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344889.jpg?v=1768861988","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344888.jpg?v=1768861928","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344887.jpg?v=1768861868","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344886.jpg?v=1768861810","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344885.jpg?v=1768861750","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344884.jpg?v=1768861688","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344883.jpg?v=1768861628","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344882.jpg?v=1768861569","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344881.jpg?v=1768861508","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344880.jpg?v=1768861449","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344879.jpg?v=1768861388","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217344878.jpg?v=1768861328","https://cdn.shopify.com/s/files/1/0225/2721/3642/files/apos-audio-cayin-dac-digital-to-analog-converter-cayin-ru7-1-bit-resistor-network-portable-dac-1217520167.jpg?v=1768909988"],"price":289,"currency":"USD","in_stock":true,"inventory_qty":9999,"dynamic_pricing":false,"listed_at":"2026-06-20T16:25:56.113Z"},"share_url":"https://firestarter.network/l/lst_Vs3XQtFC","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_Vs3XQtFC' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy Cayin RU7 1-Bit Resistor Network Portable DAC' and a budget_max comfortably above $289.00 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."]}}