{"id":26431,"date":"2010-05-14T14:38:50","date_gmt":"2010-05-14T12:38:50","guid":{"rendered":"http:\/\/cyberfarm-wp.flywheelsites.com\/?product=api-550b"},"modified":"2026-02-13T12:48:04","modified_gmt":"2026-02-13T11:48:04","slug":"api-550b","status":"publish","type":"product","link":"https:\/\/cyberfarm.dk\/en\/api-550b\/","title":{"rendered":"API 550B"},"content":{"rendered":"

API 550B 4-Band Equalizer \u2013 500 Series<\/h2>\n

The API 550B<\/strong> is a classic 4-band equalizer<\/strong> in the compact and versatile 500 Series format<\/strong>, offering the legendary tone and design heritage of API\u2019s original 1967 550 EQ \u2014 now with an added fourth band for enhanced tonal control. Perfect for tracking, mixing, or mastering, the 550B delivers musical, repeatable EQ shaping with the unmistakable analog warmth and punch API is known for.<\/p>\n

Each of the four bands provides seven carefully selected frequency centres<\/strong>, chosen by API engineers to deliver musical results across a wide range of applications. With up to \u00b112 dB of boost or cut<\/strong> per band and the renowned “Proportional Q”<\/strong> design, the 550B naturally adjusts the bandwidth of the filter \u2014 wide at subtle settings and narrower at more extreme boosts or cuts, making it easy to dial in precise tonal shaping that always sounds natural.<\/p>\n

Bands 1 and 4 can be switched between peak and shelving modes, further extending the unit\u2019s flexibility for bass, vocals, guitars, and mix bus duties. Built with API\u2019s fully discrete analog circuit design<\/strong> and featuring the iconic 2520 op amp<\/strong>, the 550B offers incredibly high headroom, with a clip point at +30 dB \u2014 perfect for today\u2019s high-resolution audio workflows.<\/p>\n

Key Features:<\/h3>\n
    \n
  • Four bands of classic API equalization<\/li>\n
  • Each band offers seven API-selected frequency centers<\/li>\n
  • \u00b112 dB boost\/cut per band<\/li>\n
  • Bands 1 and 4 offer peak or shelf switching<\/li>\n
  • \u201cProportional Q\u201d design for musical, natural EQ curves<\/li>\n
  • Fully discrete circuit design with API 2520 op amps<\/li>\n
  • Reissue of the 1967 API 550 EQ with added fourth band<\/li>\n
  • High headroom design with +30 dB clip level<\/li>\n
  • Fits all standard 500 Series racks<\/li>\n<\/ul>\n

    The API 550B<\/strong> combines vintage EQ character with modern flexibility, offering legendary API tone in a powerful and intuitive format \u2014 a must-have equalizer for any serious engineer working in the 500 Series environment.<\/p>","protected":false},"excerpt":{"rendered":"

    API 550B 4-Band Equalizer \u2013 500 Series The API 550B is a classic 4-band equalizer in the compact and versatile 500 Series format, offering the legendary tone and design heritage of API\u2019s original 1967 550 EQ \u2014 now with an added fourth band for enhanced tonal control. Perfect for tracking, mixing, or mastering, the 550B […]\n","protected":false},"featured_media":70067,"template":"","meta":{"_seopress_titles_title":"","_seopress_titles_desc":"%%post_excerpt%%","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"none","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"both","_seopress_redirections_param":"","_seopress_redirections_type":301,"_seopress_analysis_target_kw":"API 550B,500 series equalizer,4-band EQ,API EQ module,proportional Q equalizer,API 2520 op amp,peak shelf EQ,reissue API 550,analog EQ module,lunchbox EQ,studio EQ processor,high headroom equalizer,API 500 series EQ,discrete analog EQ,musical EQ filter","_seopress_news_disabled":"","_seopress_video_disabled":"","_seopress_video":[],"_seopress_pro_schemas_manual":[],"_seopress_pro_rich_snippets_disable_all":"","_seopress_pro_rich_snippets_disable":[],"_seopress_pro_schemas":[]},"product_brand":[4095],"product_cat":[1828,1830],"product_tag":[],"class_list":["post-26431","product","type-product","status-publish","has-post-thumbnail","product_brand-api","product_cat-500-series","product_cat-equalizer","first","onbackorder","taxable","shipping-taxable","purchasable","product-type-simple"],"publishpress_future_action":{"enabled":false,"date":"2026-06-28 05:38:47","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"product_tag","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/cyberfarm.dk\/en\/wp-json\/wp\/v2\/product\/26431","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cyberfarm.dk\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/cyberfarm.dk\/en\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cyberfarm.dk\/en\/wp-json\/wp\/v2\/media\/70067"}],"wp:attachment":[{"href":"https:\/\/cyberfarm.dk\/en\/wp-json\/wp\/v2\/media?parent=26431"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/cyberfarm.dk\/en\/wp-json\/wp\/v2\/product_brand?post=26431"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/cyberfarm.dk\/en\/wp-json\/wp\/v2\/product_cat?post=26431"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/cyberfarm.dk\/en\/wp-json\/wp\/v2\/product_tag?post=26431"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}