{"product_id":"reed-sf-optical-cartridge","title":"Reed SF Optical Cartridge","description":"\u003cp\u003eThe Reed SF is the company’s first cartridge, and a particular kind of first move: not a magnet, not a coil, but light. Reed entered the cartridge category alongside the engineers in Japan who first proved an optical reading of the groove could outperform the electromechanical alternatives — and added their own thinking to the body, the cantilever assembly, and the materials that surround the moving parts.\u003c\/p\u003e\n\n\u003cp\u003eThe principle is elegantly direct. A miniature shutter, mounted at the cantilever, modulates the light from a pair of infrared LEDs as the stylus traces the groove. Photodiodes read the brightness change, channel by channel, and the output is the music. There is no magnet to drag against, no coil to generate its own back-EMF, no electromechanical compromise between sensitivity and mass. The moving structure is almost weightless. The signal it produces is fully analog — the optical principle is the reading mechanism, not a sampling layer — and the cartridge is free to follow the groove rather than to push against itself.\u003c\/p\u003e\n\n\u003cp\u003eWhat the listener hears is the consequence of a much lower moving mass than any conventional cartridge can offer. Transients arrive cleanly. The leading edge of a piano note, the breath before a vocal line, the brush hitting the snare — those events sit in the air rather than smearing into the air around them. The bass is unforced; the top end is open without being lit; the noise floor falls away in the way that ordinarily costs a great deal in front-end isolation alone. Records you thought you knew show their hand.\u003c\/p\u003e\n\n\u003cp\u003eThe body is machined HD phenolic resin chosen after comparative shock-wave testing of several damping materials — phenolic settled the test signal in roughly an eighth of the time the aluminium control sample took, which is the kind of difference one hears immediately. The cantilever is sapphire. The stylus is a micro-ridge profile, set up at Reed for a tracking force of around 2.1 grams. Channel separation, output level, and compliance are all in the range a Reed tonearm — or any well-built medium-mass arm — was made to drive.\u003c\/p\u003e\n\n\u003cp\u003eThe Reed SF is designed to be paired with Reed’s own EQ phono equalizer, where it expresses its full character. It is also compatible with the energizer-style phono stages built by other makers of optical cartridges, so an owner already inside that ecosystem can audition the Reed without rebuilding the front end.\u003c\/p\u003e\n\n\u003cp\u003eAvailable at both Alma showrooms. We are happy to arrange a private session in the listening room — the Reed SF responds to careful setup more than most cartridges, and is best heard with the system around it tuned for it. Contact us to schedule.\u003c\/p\u003e","brand":"Reed","offers":[{"title":"Default Title","offer_id":48892034711771,"sku":null,"price":12975.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1363\/6553\/files\/Reed-SF-optical-cartridge.jpg?v=1781924706","url":"https:\/\/almaaudio.com\/products\/reed-sf-optical-cartridge","provider":"Alma Music and Audio","version":"1.0","type":"link"}