{"id":63,"date":"2009-06-14T05:11:44","date_gmt":"2009-06-14T10:11:44","guid":{"rendered":"http:\/\/abrammorphew.com\/notes\/?p=63"},"modified":"2016-08-22T13:00:44","modified_gmt":"2016-08-22T18:00:44","slug":"exploring-the-lm386","status":"publish","type":"post","link":"http:\/\/abrammorphew.com\/notes\/2009\/06\/14\/exploring-the-lm386\/","title":{"rendered":"exploring the LM386&#8230;"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/abrammorphew.com\/notes\/wp-content\/uploads\/2009\/06\/img_1388-300x225.jpg\" alt=\"img_1388\" title=\"img_1388\" width=\"300\" height=\"225\" class=\"alignnone size-medium wp-image-64\" srcset=\"http:\/\/abrammorphew.com\/notes\/wp-content\/uploads\/2009\/06\/img_1388-300x225.jpg 300w, http:\/\/abrammorphew.com\/notes\/wp-content\/uploads\/2009\/06\/img_1388-1024x768.jpg 1024w, http:\/\/abrammorphew.com\/notes\/wp-content\/uploads\/2009\/06\/img_1388.jpg 1600w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>In my attempts to recently mod a Peavey Classic 30, I&#8217;ve been researching audio amplification like a demented mad scientist scheming to destroy the world. I&#8217;ve understood the conceptual model of amplification for a while, but I&#8217;ve never actually plunged into the crafting part of it before now. After changing out some tone caps, I couldn&#8217;t help but wonder how something like capacitance could actually affect the way the electrical signals are converted back into mechanical sound even though it&#8217;s pretty obvious.<\/p>\n<p>A while ago I came across a schematic that included a simple 8-pin IC as the workhorse of the circuit. It&#8217;s called the LM386, and it&#8217;s got to have near a thousand uses judging by the amount of information about it.  My cohorts and I have been toying with the idea of <em>headphone sessions<\/em>, a improvisational mixing session where the four of us write and play music while being conscious of the stereo field. This of course requires the purchase of a headphone amp. Why buy one when you can just build one. <\/p>\n<p>I played with the LM386 for about five hours. It was mostly blind experimentation since I was just using parts I could pull off other dead devices. I had also purchased a shitload of resistors earlier in the day which I was also dying to play around with. I could only get it to sound clear enough at lower volumes through a .5 Watt speaker with a tear in the cone. It seems ample enough for headphones. I figure four dual PCBs with essentially 8 tiny amps attached to a pot on the jack should just very well do the trick. I&#8217;ll make a better effort to document as well. <\/p>\n<p><object width=\"400\" height=\"300\"><param name=\"allowfullscreen\" value=\"true\" \/><param name=\"allowscriptaccess\" value=\"always\" \/><param name=\"movie\" value=\"http:\/\/vimeo.com\/moogaloop.swf?clip_id=5149655&amp;server=vimeo.com&amp;show_title=1&amp;show_byline=1&amp;show_portrait=0&amp;color=&amp;fullscreen=1\" \/><embed src=\"http:\/\/vimeo.com\/moogaloop.swf?clip_id=5149655&amp;server=vimeo.com&amp;show_title=1&amp;show_byline=1&amp;show_portrait=0&amp;color=&amp;fullscreen=1\" type=\"application\/x-shockwave-flash\" allowfullscreen=\"true\" allowscriptaccess=\"always\" width=\"400\" height=\"300\"><\/embed><\/object><\/p>\n<p><a href=\"http:\/\/vimeo.com\/5149655\">lm386 amp made with random caps<\/a> from <a href=\"http:\/\/vimeo.com\/user1901291\">abram<\/a> on <a href=\"http:\/\/vimeo.com\">Vimeo<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In my attempts to recently mod a Peavey Classic 30, I&#8217;ve been researching audio amplification like a demented mad scientist scheming to destroy the world. I&#8217;ve understood the conceptual model of amplification for a while, but I&#8217;ve never actually plunged into the crafting part of it before now. After changing out some tone caps, I [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[25,26,20],"class_list":["post-63","post","type-post","status-publish","format-standard","hentry","category-notes","tag-audio","tag-breadboard","tag-lm386"],"_links":{"self":[{"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/posts\/63","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/comments?post=63"}],"version-history":[{"count":6,"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/posts\/63\/revisions"}],"predecessor-version":[{"id":398,"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/posts\/63\/revisions\/398"}],"wp:attachment":[{"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/media?parent=63"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/categories?post=63"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/abrammorphew.com\/notes\/wp-json\/wp\/v2\/tags?post=63"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}