{"product_id":"burwen-research-dnf-1201a","title":"Burwen Research DNF 1201A Dynamic Noise Filter","description":"\u003cp\u003e\n Burwen Research DNF 1201A Dynamic Noise Filter — tested and working.\n\u003c\/p\u003e\n\u003cp\u003e\n A single-ended dynamic noise filter from the late 1970s, designed by Richard Burwen. Unlike Dolby or dbx, it needs no encoded source — it works on any program material, so it's useful for cleaning hiss off reel-to-reel tapes, cassettes, 78s, off-air FM, and shortwave audio. The filter tracks program content, sliding the high-frequency cutoff down during quiet passages and opening back up on transients so you keep the top end where it matters.\n\u003c\/p\u003e\n\u003cp\u003e\n \u003cb\u003e\n  \u003cstrong\u003e\n   Condition:\n  \u003c\/strong\u003e\n \u003c\/b\u003e\n Very good. Faceplate and knobs are clean with only light handling marks from normal use. [Note any specific nicks\/scratches here.] All switches and controls operate smoothly with no scratchiness. Rubber feet present. Serial #[fill in].\n\u003c\/p\u003e\n\u003cp\u003e\n \u003cb\u003e\n  \u003cstrong\u003e\n   Testing:\n  \u003c\/strong\u003e\n \u003c\/b\u003e\n Powered up and passed audio through both channels. Filter action verified audibly — noise reduction engages and defeats correctly via the front panel. Tape monitor loop functions. No hum, no channel imbalance, no intermittents.\n\u003c\/p\u003e\n","brand":"Burwen Research","offers":[{"title":"Default Title","offer_id":67788241436899,"sku":null,"price":105.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/6544\/1507\/files\/e697db5f-39cc-4ddc-928f-8aaaff5c0464.jpg?v=1792769728","url":"https:\/\/bluewater-pro.com\/products\/burwen-research-dnf-1201a","provider":"Bluewater Pro","version":"1.0","type":"link"}