{"product_id":"trickfish-j-core-jazz-bass-plate-preamp-drop-in-active-jazz-bass-preamp-mike-pope-designed-flexcore-circuit-4-band-side-mount","title":"Trickfish | J-Core Jazz Bass Plate Preamp | Mike Pope-Designed FlexCore Circuit | 4-Band \u0026 Side Mount Jack","description":"\u003cp class=\"p1\"\u003eThe Trickfish J-Core Jazz Plate Preamp brings the acclaimed Flexcore onboard bass preamp into a convenient drop-in Jazz Bass control plate format. Designed for players who want a serious active preamp upgrade without modifying their instrument, the J-Core installs into a standard Jazz Bass control cavity with no soldering required.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eAt the heart of the J-Core is the Mike Pope-designed Flexcore preamp circuit, known for its clarity, warmth, punch, and musical response. Available in either 2-band or 4-band EQ configurations, it gives Jazz Bass players a highly flexible tonal platform while preserving the familiar feel and layout of the instrument.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe 4-band version offers deep control over bass, low mids, high mids, and treble, with internally selectable frequency centres for each band. Rocker-style mini switches replace traditional jumper selectors, making it easier to fine-tune the EQ response to suit your bass, playing style, and preferred tone.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eFor players who prefer a simpler setup, the 2-band version provides powerful bass and treble shaping in a streamlined format. Both versions also include selectable output gain options, allowing you to set the preamp response and level to better match your instrument, amp, and signal chain.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe J-Core also retains the importance of a proper passive tone control, with a stock .022 capacitor and the option to customise the response with an additional through-hole parallel capacitor. Complete with a prewired output jack, battery connector clip, and preinstalled Jazz Bass control plate, the Trickfish J-Core is a premium upgrade for players who want active flexibility without losing the classic Jazz Bass identity.\u003c\/p\u003e\n\u003cp class=\"p2\"\u003eFeatures:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eDrop-in active preamp for Jazz Bass-style instruments\u003c\/li\u003e\n\u003cli\u003eBased on the acclaimed Trickfish Flexcore onboard bass preamp\u003c\/li\u003e\n\u003cli\u003eMike Pope-designed preamp circuit\u003c\/li\u003e\n\u003cli\u003eAvailable in 2-band or 4-band EQ configurations\u003c\/li\u003e\n\u003cli\u003eNo soldering required\u003c\/li\u003e\n\u003cli\u003eDesigned to fit into an existing Jazz Bass control cavity\u003c\/li\u003e\n\u003cli\u003eIncludes prewired output jack\u003c\/li\u003e\n\u003cli\u003eIncludes battery connector clip\u003c\/li\u003e\n\u003cli\u003ePreinstalled on a Jazz Bass control plate\u003c\/li\u003e\n\u003cli\u003eInternally selectable EQ frequency centres\u003c\/li\u003e\n\u003cli\u003eRocker-style mini switches for easier internal adjustment\u003c\/li\u003e\n\u003cli\u003eSelectable output gain: 0dB, +3dB, +6dB, or +8dB\u003c\/li\u003e\n\u003cli\u003ePassive tone control with stock .022 capacitor\u003c\/li\u003e\n\u003cli\u003eCan be customised with an additional through-hole parallel capacitor\u003c\/li\u003e\n\u003cli\u003eMatte black knobs available as an option\u003c\/li\u003e\n\u003cli\u003e2-band version available with top-mounted jack\u003c\/li\u003e\n\u003cli\u003e4-band version available with side-mounted jack\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"p2\"\u003eFrequency Specifications:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eTreble: +\/- 15dB at 6kHz or 10kHz\u003c\/li\u003e\n\u003cli\u003eHigh Mid: +\/- 15dB at 600Hz or 900Hz\u003c\/li\u003e\n\u003cli\u003eLow Mid: +\/- 12dB at 330Hz or 473Hz\u003c\/li\u003e\n\u003cli\u003eBass: +\/- 12dB at 46Hz or 90Hz\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/1764\/4443\/files\/Screenshot2026-05-13at12.54.07PM.png?v=1778640893\" alt=\"\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/1764\/4443\/files\/Screenshot2026-05-13at12.54.14PM.png?v=1778640895\" alt=\"\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/1764\/4443\/files\/Screenshot2026-05-13at12.54.21PM.png?v=1778640897\" alt=\"\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/1764\/4443\/files\/Screenshot2026-05-13at12.54.26PM.png?v=1778640898\" alt=\"\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/1764\/4443\/files\/Screenshot2026-05-13at12.54.28PM.png?v=1778640901\" alt=\"\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/1764\/4443\/files\/Screenshot2026-05-13at12.54.38PM.png?v=1778640903\" alt=\"\"\u003e\u003c\/p\u003e","brand":"Trickfish Amplification","offers":[{"title":"Default Title","offer_id":41408653197370,"sku":"Trickfish-J-Core-4Band","price":499.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1764\/4443\/files\/trickfish-j-core-jazz-bass-plate-preamp-mike-pope-designed-flexcore-circuit-4-band-side-mount-jack-trickfish-j-core-4band-gsus4-4588624.jpg?v=1778691131","url":"https:\/\/gsus4.com.au\/products\/trickfish-j-core-jazz-bass-plate-preamp-drop-in-active-jazz-bass-preamp-mike-pope-designed-flexcore-circuit-4-band-side-mount","provider":"Gsus4","version":"1.0","type":"link"}