{"title":"Upgrade Kits","description":"\u003cp\u003eCan you improve upon perfection? We think so. Our upgrades can bring additional functionality or reduce noise. Buy upgrades whenever you want, but we recommend building your kits stock before upgrading. \u003c\/p\u003e","products":[{"product_id":"s-e-x-3-0-c4s-upgrade-kit","title":"Bottlehead S.E.X. 3.0 C4S Upgrade Kit","description":"\u003cp\u003eThis easy-to-install kit that will give your current version 3.0 S.E.X. kit a more quiet background, better resolution and tighter bass. This kit is available for pre-January 2023 S.E.X. 3.0 kits. \u003cstrong\u003eAs of January 2023 this kit is included with the Basic S.E.X. 3.0 kit. \u003c\/strong\u003e\u003cstrong\u003eThis kit will not work with earlier S.E.X kits\u003c\/strong\u003e\u003cstrong\u003e.\u003c\/strong\u003e\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52093290709361,"sku":"UP-SEX-3-0-C4S","price":49.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/sex-30-c4s-upgrade-kit-6992978.jpg?v=1752975602"},{"product_id":"speedball-1-1-upgrade-for-crack-amplifier","title":"Bottlehead Speedball 1.1 Upgrade for Crack Amplifier","description":"\u003cp class=\"p1\"\u003eUnlock the full potential of your Crack with the Speedball upgrade—a high-performance constant current source (CCS) modification that elevates your amp’s dynamics, clarity, and resolution. By replacing the stock plate load resistors with active current sources, Speedball tightens bass, improves treble extension, and enhances imaging without losing the signature warmth and smoothness of the original design.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eWhether you’re building a Crack from scratch or adding this to an existing build, Speedball brings a clear and immediate sonic upgrade—and a fun, accessible mod for DIYers looking to take their amp to the next level. Buying this upgrade at the same time as buying a Crack saves you 10% off the upgrade's cost.\u003c\/p\u003e\n\u003cp\u003eThe same Speedball 1.1 kit is an upgrade for Crack 1.1 and the original Crack. Most builders can complete this upgrade in an evening, but remember that there is no award for the fastest build. Check out our \u003ca title=\"Bottlehead Forums\" href=\"https:\/\/forums.bottlehead.mom\" target=\"_blank\" rel=\"noopener\"\u003euser forums\u003c\/a\u003e for more impressions and tech support.\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52093293396337,"sku":"UP-SPEEDBALL-1-1","price":115.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/bottlehead-speedball-11-upgrade-for-crack-amplifier-1699557.png?v=1769900048"},{"product_id":"twoquiet-stepped-attenuator-upgrade-for-crackatwoa","title":"Bottlehead TwoQuiet Stepped Attenuator Upgrade for Crackatwoa Headphone Amplifier","description":"\u003cp class=\"p1\"\u003eThe TwoQuiet upgrade replaces the Crackatwoa’s stock volume potentiometer with a precision 36-step attenuator, offering ultra-low noise, superior channel balance, and a more refined listening experience. Using high-quality resistors and a dual mono ladder design, the TwoQuiet delivers transparent volume control with consistent left-right tracking across all listening levels.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eWhether you’re listening at whisper-quiet volumes or driving your headphones with authority, the TwoQuiet upgrade ensures smoother operation, better imaging, and a tactile, high-end feel that enhances both performance and usability.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eMost users can build and install this upgrade in an evening or two.\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52093293429105,"sku":"UP-TWOQUIET-CRACKATWOA","price":269.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/twoquiet-stepped-attenuator-upgrade-for-crackatwoa-headphone-amplifier-3937605.jpg?v=1752975600"},{"product_id":"dc-filament-supply-for-kaiju-300b-amplifier","title":"DC filament supply for Bottlehead Kaiju 300B amplifier","description":"\u003cp\u003eThe Kaiju DC filament supply upgrade is a regulated DC supply conversion for the AC heated 300B filaments of the stock Bottlehead Kaiju 300B amplifier. There is a separate DC supply for each 300B, composed of low voltage drop Schottky rectifiers, a CLC filter using a common mode choke, and a low noise regulator optimized for fast transient response.\u003c\/p\u003e\n\u003cp\u003eThis supply will reduce the already exceptionally low noise floor of the AC heated Kaiju amplifier to levels acceptable for use with the most sensitive horn speakers. Its installation is recommended in particular for use with speakers above 96dB@1W@1M sensitivity. It may also be useful in systems employing speakers with a lower sensitivity, enhancing the sense of a black background between the notes or in quiet passages of music.\u003c\/p\u003e\n\u003cp\u003eThis kit is mostly constructed on a printed circuit board. Experienced builders can expect to complete the upgrade in an evening or two (but take your time!). \u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52102751945073,"sku":"UP-KAIJU-DC-FILAMENT-SUPPLY","price":195.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/dc-filament-supply-for-kaiju-300b-amplifier-5576316.jpg?v=1752975578"},{"product_id":"dc-filament-supply-for-stereomour-ii-amplifier","title":"DC filament supply for Bottlehead Stereomour II amplifier","description":"\u003cp\u003eThe Stereomour II DC filament supply upgrade is a DC supply conversion for the AC heated 2A3 filaments of the stock Stereomour II amplifier. There is a separate DC supply for each 2A3, composed of low voltage drop Schottky rectifiers, a CLC filter using a common mode choke. This supply will reduce the already exceptionally low noise floor of the AC heated Stereomour II amplifier to levels acceptable for use with the most sensitive horn speakers.\u003c\/p\u003e\n\u003cp\u003eIts installation is recommended in particular for use with speakers above 96dB@1W@1M sensitivity. It may also be useful in systems employing speakers with a lower sensitivity, enhancing the sense of a super black background between the notes or in quiet passages of your music.\u003c\/p\u003e\n\u003cp\u003ePlease note that this upgrade is only to be installed in the Stereomour II. The original Stereomour uses a different power transformer that is not compatible with this upgrade.\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52102751977841,"sku":"UP-STEREOMOUR-II-DC-FILAMENT-SUPPLY","price":195.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/dc-filament-supply-for-stereomour-ii-amplifier-1513798.jpg?v=1752975578"},{"product_id":"mourquiet-stepped-attenuator-upgrade-for-stereomour-ii","title":"MourQuiet Stepped Attenuator Upgrade for Stereomour II","description":"\u003cp\u003eWhen we were developing the BeePre 300B preamp kit we built the prototype preamp circuit itself on a pair of chassis, and we built several outboard chassis platforms that allowed us to try various attenuator schemes. We tried all sorts of schemes: inexpensive carbon potentiometers, our old standby Sweetest whispers attenuator, high end stepped attenuators from other manufacturers, transformer volume controls, ladders, shunts, series steps, etc., etc. The end result was the popular BeeQuiet attenuator upgrade for the BeePre.\u003c\/p\u003e\n\u003cp\u003eThis design beat out the others by quite a sonic margin, and now the same 36 step attenuator design is available as an upgrade for the Stereomour II amplifier (this kit will not fit in earlier versions of the Stereomour amp).\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52102752010609,"sku":"UP-STEREOMOUR-II-MOURQUIET","price":269.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/mourquiet-stepped-attenuator-upgrade-for-stereomour-ii-1409857.jpg?v=1752975578"},{"product_id":"stereomour-ii-shunt-regulator-upgrade-kit","title":"Stereomour II Shunt Regulator Upgrade Kit","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eDirectly heated triodes like the 2A3 output tubes used in the Stereomour II amplifier are exceptionally linear, which contributes to a DHT amp‚Äôs great sense of realism. One of the challenges of designing a fully capable DHT amp is to make the preceding driver stage as close as possible to the output stage in terms of linearity without sacrificing gain. We use a couple of different means to optimize the performance of the driver stage.\u003c\/span\u003e\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52102752043377,"sku":"UP-STEREOMOUR-II-SHUNT-REGULATOR","price":89.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/stereomour-ii-shunt-regulator-upgrade-kit-8177837.jpg?v=1752975578"},{"product_id":"moreplay-upgrade-kit","title":"Moreplay Upgrade Kit","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eThis kit incorporates our tried and true power supply upgrades as well as upgrading the stock potentiometers to the great sounding Alps Blue series. The result is a more quiet background, about 6dB more gain and improved resolution.\u003c\/span\u003e\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52102752108913,"sku":"UP-MOREPLAY-UPGRADE","price":289.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/moreplay-upgrade-kit-1867524.jpg?v=1752975577"},{"product_id":"beepre2-output-upgrade-hybrid-shunt-regulator-and-low-impedance-balanced-output","title":"BeePre2 Output Upgrade - Hybrid Shunt Regulator and Low Impedance Balanced Output","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eThis upgrade kit is for the current production \u003c\/span\u003e\u003ca href=\"https:\/\/bottlehead.mom\/products\/beepre2-300b-preamplifier-kit\" title=\"Bottlehead BeePre2 300B Preamplifier Kit\" target=\"_blank\"\u003eBeePre2\u003c\/a\u003e\u003cspan\u003e (10\" x 16\" chassis - It will not work at all with the original BeePre in the 12\" x 12\" chassis) \u003c\/span\u003e\u003cstrong\u003ethat has already had the\u003ca href=\"https:\/\/www.bottlehead.mom\/products\/bee2quiet-upgrade-for-beepre2\" title=\"Bee2Quiet Upgrade Kit for Bottlehead BeePre2\" rel=\"noopener\" target=\"_blank\"\u003e Bee2Quiet upgrade\u003c\/a\u003e installed\u003c\/strong\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThe Hybrid Shunt Regulator and Low Impedance Balanced Output upgrade kit lowers output impedance substantially to about 400 ohms from the unbalanced output, allows for the addition of balanced XLR outputs, and - as a bonus - removes turn-on thumps you normally get with simple single-stage circuits thanks to a slower warm-up behavior.\u003cbr\u003e\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52102752174449,"sku":"UP-BEEPRE2-SHUNT-REGULATOR","price":249.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/beepre2-output-upgrade-hybrid-shunt-regulator-and-low-impedance-balanced-output-8764086.jpg?v=1752975576"},{"product_id":"bee2quiet-upgrade-for-beepre2","title":"Bee2Quiet Stepped Attenuator\/Constant Current Source Upgrade for BeePre2","description":"\u003cp\u003e\u003cstrong\u003e\u003cmeta charset=\"utf-8\"\u003e\u003c\/strong\u003e\u003cspan\u003e\u003cem\u003eThis upgrade kit is for the current production BeePre2 only (10\" x 16\" chassis). \u003cstrong\u003eIt will not work at all with the original BeePre (12\" x 12\" chassis)\u003c\/strong\u003e. \u003c\/em\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe Bee2Quiet replaces the stock volume control on your BeePre2 with a stepped attenuator featuring stereo coarse and fine controls with thirty-six 1.5dB steps for a total of -52.5dB attenuation.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eWe provide all the parts you need, including the high quality rotary switches, Vishay Dale metal film resistors, and the required hardware. As with every Bottlehead kit, you'll also receive an extremely detailed manual and support from our forum.\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52102752207217,"sku":"UP-BEEPRE2-BEE2QUIET","price":349.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/bee2quiet-stepped-attenuatorconstant-current-source-upgrade-for-beepre2-4027713.jpg?v=1752975576"},{"product_id":"integration-upgrade-for-reduction-phono-preamp","title":"Integration Upgrade for Reduction Phono Preamp","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eNow the benefits of increased dynamics, more quiet background, better bass control, more gain and a sense of better frequency extension can be had for the Reduction Phono Preamp\u003c\/span\u003e\u003cspan\u003e. Four Camille Cascode Constant Current Sources (C\u003c\/span\u003e\u003csup\u003e4\u003c\/sup\u003e\u003cspan\u003eS) replace the stock plate load resistors, dramatically increasing the load impedance for approximately 60dB better Power Supply Ripple Rejection (PSRR) and the extraction of the full gain available from the tubes (up from about 36dB to about 40dB). The addition of a Zener shunt voltage regulator lowers the power supply impedance yielding a sense of increased extension of both bass and treble.\u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eNote that this is for the Reduction Phono Preamp and not the Eros or Eros 2.\u003c\/span\u003e\u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":52102752272753,"sku":"UP-REDUCTION-INTEGRATION","price":179.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/integration-upgrade-for-reduction-phono-preamp-1200789.jpg?v=1752975573"},{"product_id":"pjccs-upgrade-for-the-bottlehead-quickie","title":"PJCCS Upgrade for the Bottlehead Quickie","description":"\u003cp\u003eThis is a constant current source upgrade for the retired Bottlehead Quickie preamp kit. It cannot be used in any other kits. \u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Default Title","offer_id":62827724210545,"sku":"UP-PJCCS","price":45.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/pjccs-upgrade-for-the-bottlehead-quickie-1535673.jpg?v=1766585646"},{"product_id":"paradyne-illuminated-meter-kit","title":"Paradyne Illuminated Meter Kit","description":"\u003cp\u003eFor a handful of reasons, the Bottlehead Paradyne 805A Monoblocks come with an unlit meter by default. It is possible to add a lit meter to the kit after the base build is completed.\u003c\/p\u003e\n\u003cp\u003eThis kit is for Paradyne owners who want to customize their kit with lit meters. We provide two lit meters and some additional wire required to make the meters work. You can find \u003ca href=\"https:\/\/forums.bottlehead.mom\/threads\/how-to-add-lit-meters-to-your-paradyne.16439\/#post-145046\" target=\"_blank\" title=\"How to Add Lit Meters to Your Paradyne - Bottlehead Forums\" rel=\"noopener\"\u003einstructions for installing these meters\u003c\/a\u003e on this forum post written by Paul Birkeland. \u003c\/p\u003e","brand":"Bottlehead","offers":[{"title":"Orange","offer_id":63205940691313,"sku":"UP-PARADYNE-LIT-METERS-OR","price":35.0,"currency_code":"USD","in_stock":true},{"title":"Green","offer_id":63205940724081,"sku":"UP-PARADYNE-LIT-METERS-GR","price":35.0,"currency_code":"USD","in_stock":true},{"title":"Blue","offer_id":63205940756849,"sku":"UP-PARADYNE-LIT-METERS-BL","price":35.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/files\/paradyne-illuminated-meter-kit-4684612.jpg?v=1774954631"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/6408\/6641\/collections\/upgrade-kits-2487747.jpg?v=1752975542","url":"https:\/\/bottlehead.mom\/collections\/upgrade-kits.oembed?page=2","provider":"Bottlehead","version":"1.0","type":"link"}