{"product_id":"bottlehead-crack-1-1-otl-headphone-amplifier-kit","title":"Bottlehead Crack 1.1 OTL Headphone Amplifier Kit","description":"\u003cp\u003eThe Bottlehead Crack 1.1 is a DIY output-transformerless (OTL) tube headphone amplifier kit designed for high-impedance headphones, including the Sennheiser HD600, HD650, and HD6XX. Crack uses a single-ended tube circuit featuring a 12AU7 input tube and a 6080 output tube. Its OTL design eliminates the output transformer, delivering the engaging listening experience that has made Crack a favorite among headphone enthusiasts.\u003c\/p\u003e\n\u003ch4\u003eDesigned for first-time builders\u003c\/h4\u003e\n\u003cp\u003eYou don't need previous amplifier-building experience to assemble Crack. The kit includes the electronic components, tubes, chassis, wood base, and detailed step-by-step assembly manual. You'll supply the tools and solder. You can read more about \u003ca href=\"https:\/\/bottlehead.com\/blogs\/bottleblog\/what-comes-in-a-bottlehead-kit\" title=\"What Comes in a Bottlehead Kit? on the Bottlehead Blog\"\u003ewhat comes in a kit\u003c\/a\u003e and \u003ca href=\"https:\/\/bottlehead.com\/blogs\/bottleblog\/what-do-i-need-to-build-my-own-bottlehead-kit\" title=\"What do I need to build a Bottlehead kit? - On the Bottlehead Blog\"\u003ewhat tools you should provide\u003c\/a\u003e in the Bottlehead blog.\u003c\/p\u003e\n\u003cp\u003eBuilding a Crack is a great introduction to point-to-point wiring and vacuum tube amplification, with technical support available through the \u003ca href=\"https:\/\/forums.bottlehead.com\" title=\"Bottlehead Forums\" rel=\"noopener\" target=\"_blank\"\u003eBottlehead forums\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch4\u003eDesigned for high-impedance headphones\u003c\/h4\u003e\n\u003cp\u003eCrack is particularly well suited to high-impedance dynamic headphones, including the Sennheiser HD600 and HD650. Its OTL design makes it an especially compelling match for headphones with impedances of 200 ohms or higher.\u003c\/p\u003e\n\u003ch4\u003eStart with Crack, modify with Speedball\u003c\/h4\u003e\n\u003cp\u003eCrack is a complete amplifier on its own, while the optional \u003ca href=\"https:\/\/www.makershed.com\/products\/bottlehead-speedball-1-1-upgrade-for-crack-amplifier\" target=\"_blank\" rel=\"noopener\"\u003eSpeedball mod\u003c\/a\u003e uses active constant-current sources to improve performance. Many builders purchase both kits together and install Speedball after completing the stock build and listening to it for a while.\u003c\/p\u003e\n\u003ch4\u003eInternational sensation\u003c\/h4\u003e\n\u003cp\u003eCrack includes a universal power transformer that can be wired for different mains voltages using the instructions in the assembly manual. International customers will need to supply their own power cord.\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":50937048268993,"sku":"HPK-CRACK-1-1","price":375.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0243\/7593\/files\/Bottlehead_Crack_1-1.jpg?v=1794329222","url":"https:\/\/www.makershed.com\/products\/bottlehead-crack-1-1-otl-headphone-amplifier-kit","provider":"Maker Shed","version":"1.0","type":"link"}