{"id":274,"date":"2025-06-29T16:19:29","date_gmt":"2025-06-29T16:19:29","guid":{"rendered":"https:\/\/cascajolabs.es\/?p=274"},"modified":"2025-06-29T16:19:30","modified_gmt":"2025-06-29T16:19:30","slug":"pcb-audio-amplifier-vu-meter","status":"publish","type":"post","link":"https:\/\/cascajolabs.es\/?p=274","title":{"rendered":"PCB: Audio amplifier + VU meter"},"content":{"rendered":"\n<p>I\u2019ve been working on a project that needed an audio amp, so I went with the <strong>LTK8002D<\/strong>. Along the way, I ended up designing a quick <strong>test PCB<\/strong> to try things out before moving on to the final version.<\/p>\n\n\n\n<p>Since I was already building the board, I used a <strong>VU meter with the LM3915N<\/strong>\u2014 handy to keep an eye on signal levels and to make sure everything was behaving as expected.<\/p>\n\n\n\n<p>I tested the setup with a <strong>MIDI controller<\/strong> and a <strong>mixing console<\/strong>, playing around with different filters and checking how the sound actually came through a speaker. That little testing phase helped catch a few issues early and tweak things before going full send on the final build.<\/p>\n\n\n\n<p>Definitely a useful side project!<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"760\" height=\"601\" src=\"https:\/\/cascajolabs.es\/wp-content\/uploads\/2025\/06\/Captura-de-pantalla-2025-06-29-175409.png\" alt=\"\" class=\"wp-image-275\" style=\"width:548px;height:auto\" srcset=\"https:\/\/cascajolabs.es\/wp-content\/uploads\/2025\/06\/Captura-de-pantalla-2025-06-29-175409.png 760w, https:\/\/cascajolabs.es\/wp-content\/uploads\/2025\/06\/Captura-de-pantalla-2025-06-29-175409-300x237.png 300w\" sizes=\"auto, (max-width: 760px) 100vw, 760px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"has-text-align-left wp-embed-aspect-16-9 wp-has-aspect-ratio\">This is a test of the board using an ESP32-S3 and an AKAI MPK MIDI controller.<\/p>\n\n\n\n<figure class=\"wp-block-embed aligncenter is-type-rich is-provider-embed-handler wp-block-embed-embed-handler wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"ESP32 S3 + AKAI MPK MINI | Arpeggiator #electronics #music\" width=\"750\" height=\"422\" src=\"https:\/\/www.youtube.com\/embed\/rQk3snaPMKI?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>I\u2019ve been working on a project that needed an audio amp, so I went with the LTK8002D. Along the way, I ended up designing a quick test PCB to try things out before moving on to the final version. Since I was already building the board, I used a VU [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":278,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[78,74,70,76,72],"class_list":["post-274","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","tag-akai-mpk","tag-altium","tag-esp32s3","tag-midi","tag-pcb"],"_links":{"self":[{"href":"https:\/\/cascajolabs.es\/index.php?rest_route=\/wp\/v2\/posts\/274","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cascajolabs.es\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cascajolabs.es\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cascajolabs.es\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cascajolabs.es\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=274"}],"version-history":[{"count":4,"href":"https:\/\/cascajolabs.es\/index.php?rest_route=\/wp\/v2\/posts\/274\/revisions"}],"predecessor-version":[{"id":281,"href":"https:\/\/cascajolabs.es\/index.php?rest_route=\/wp\/v2\/posts\/274\/revisions\/281"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cascajolabs.es\/index.php?rest_route=\/wp\/v2\/media\/278"}],"wp:attachment":[{"href":"https:\/\/cascajolabs.es\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=274"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cascajolabs.es\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=274"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cascajolabs.es\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=274"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}