{"id":13544,"date":"2020-06-23T17:56:55","date_gmt":"2020-06-24T00:56:55","guid":{"rendered":"https:\/\/rustybolt.info\/wordpress\/?p=13544"},"modified":"2020-06-23T18:53:49","modified_gmt":"2020-06-24T01:53:49","slug":"2020-06-23-lm386-1w-mono-amplifier-input-jack-reconfig","status":"publish","type":"post","link":"https:\/\/rustybolt.info\/wordpress\/?p=13544","title":{"rendered":"2020-06-23 LM386 1W Mono Amplifier Input Jack Reconfig"},"content":{"rendered":"

A year or so ago I bought a few 1W mono amplifiers from a Chinese eBay seller for cheap – see the attached photos. The only marking on the PC board is YX-1667 but I’m not sure if that’s the potentiometer or the PC board itself.
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I found that if I pushed the 3.5mm plug all the way in to the input jack like it’s supposed to be, it didn’t have continuity, I had to leave the plug pushed halfway into the jack for it to work. So I just left it that way. I checked the jack and it was connected to the volume control improperly, the Ring was connected instead of the Tip.
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So now I decided to correct the problem. I also found that the input had a 0.1 uF (104) ceramic capacitor between the jack and the volume control, which isn’t needed for DC blocking because there is no DC; however it does roll off the low frequencies so I decided it wasn’t needed, but it can be left in the circuit.
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I decided to put a short insulated jumper wire between the outermost unused jack pin directly to the pin of the 100k potentiometer. I soldered it like shown in the PC side of the board, being careful that the jumper didn’t short to the grounded copper foil that is close to the jack pin.
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Another way to do this would be to cut the pad from the soldered jack pins in half. Then solder a jumper from the outermost unconnected jack pin to the capacitor half of the cut pad. This will keep the capacitor in the circuit.<\/p>\n

.End of this blog post.<\/p>\n","protected":false},"excerpt":{"rendered":"

A year or so ago I bought a few 1W mono amplifiers from a Chinese eBay seller for cheap – see the attached photos. The only marking on the PC board is YX-1667 but I’m not sure if that’s the potentiometer or the PC board itself. . I found that if I pushed the 3.5mm <\/p>\n

(Read More…)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[347,327,8,263,329,357],"tags":[434],"class_list":["post-13544","post","type-post","status-publish","format-standard","hentry","category-amplifier","category-assemblies","category-audio","category-errors","category-functional-blocks","category-modification","tag-yx-1667"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/13544","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=13544"}],"version-history":[{"count":9,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/13544\/revisions"}],"predecessor-version":[{"id":13555,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/13544\/revisions\/13555"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=13544"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=13544"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=13544"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}