{"id":1319,"date":"2018-04-15T01:14:00","date_gmt":"2018-04-14T23:14:00","guid":{"rendered":"http:\/\/tomashg.com\/?p=1319"},"modified":"2021-09-29T01:17:17","modified_gmt":"2021-09-28T23:17:17","slug":"cv-sequencer-ghz-labs","status":"publish","type":"post","link":"https:\/\/tomashg.com\/?p=1319","title":{"rendered":"CV Sequencer \u2013 GHz Labs"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">The second module designed for the workshop at\u00a0<a href=\"https:\/\/www.facebook.com\/events\/1746887871993407\/\" target=\"_blank\" rel=\"noreferrer noopener\">Common Ground<\/a>\u00a0and part of the\u00a0<a href=\"http:\/\/ghzlabs.com\/\" target=\"_blank\" rel=\"noreferrer noopener\">GHz Labs<\/a>\u00a0series, was an\u00a0<strong>8-step CV sequencer<\/strong>.\u00a0With inputs for clock, reset, 3 logic OR-ed step inputs and glide control. Utilizing the step inputs with a clock divider or any gate source can further create more complex, non-linear sequences.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe title=\"CV Sequencer  - GHz Labs (DIY Eurorack)\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/Z4Mdjvn5b3o?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 class=\"wp-block-paragraph\">Again inspired\u00a0heavily by the tutorials put together by Peter Edwards from\u00a0<a href=\"https:\/\/www.youtube.com\/watch?v=t7JYOIYqMEY\" target=\"_blank\" rel=\"noreferrer noopener\">Casper Electronics<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The sequencer is based on two very useful ICs, the<strong>\u00a0CD4024 Ripple-Carry Binary Counter<\/strong>\u00a0and the\u00a0<strong>CD4051 Analog Multiplexer<\/strong>. The Binary\u00a0Counter acts as a \u201cstep select\u201d for the Multiplexer, that\u00a0routes\u00a0one of the 8 potentiates\u00a0from it\u2019s input to it\u2019s output.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/tomashg.com\/wp-content\/uploads\/2018\/04\/sequencer_counter.jpg\" alt=\"\"\/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The potentiometers are configured as voltage dividers, giving anything from -12 to +12 volts. Followed by an attenuation circuit to prevent the Op-Amp from saturating and finally reaching the glide (or slew rate limiting) circuit.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/tomashg.com\/wp-content\/uploads\/2018\/04\/sequencer_mux-1024x496.jpg\" alt=\"\"\/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The A, B and C inputs are connected to the Multiplexer channel select inputs, OR-ed together with the Counter outputs through diodes. So that the steps can arbitrarily be switched around.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/tomashg.com\/wp-content\/uploads\/2018\/04\/sequencer_abc.jpg\" alt=\"\"\/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The first iteration of the design used two +\/- 5 V regulators, but I decided to \u201c<del>simplify<\/del>\u201d the circuit and run everything straight off the +\/- 12 V rails. Which ended in a transistor clutter to shift the clock and trigger levels from 5V to 12V.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As the Counter and Multiplexer now run on the 12V rail, the VIH Min. (minimum logic level for a high signal) would be something above 7 V.&nbsp;This&nbsp;would not quite work with Eurorack 5V trigger levels. In the next revision I might try to move the logic level shifting to a later stage of the Multiplexer Input to reduce the number of transistors needed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Let me know if you&nbsp;like this design in the comments down below!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You can find the full\u00a0<strong>schematics<\/strong>\u00a0and\u00a0<strong>BOM<\/strong>\u00a0files\u00a0<a href=\"https:\/\/github.com\/ghztomash\/CVSequencer\" target=\"_blank\" rel=\"noreferrer noopener\">here<\/a>. And the accompanying\u00a0<a href=\"http:\/\/ghzlabs.com\/eurorack\/cv-sequencer\/\" target=\"_blank\" rel=\"noreferrer noopener\">website<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The second module designed for the workshop at\u00a0Common Ground\u00a0and part of the\u00a0GHz Labs\u00a0series, was an\u00a08-step CV sequencer.\u00a0With inputs for clock, reset, 3 logic OR-ed step inputs and glide control. Utilizing the step inputs with a clock divider or any gate source can further create more complex, non-linear sequences. Again inspired\u00a0heavily by the tutorials put together [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":1321,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[234,113,32],"tags":[207,237,243,240,241,244,245,206],"class_list":["post-1319","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-eurorack","category-music-2","category-technology","tag-analog","tag-cv","tag-cv-sequencer","tag-eurorack","tag-ghz-labs","tag-modular","tag-modular-synth","tag-sequencer"],"_links":{"self":[{"href":"https:\/\/tomashg.com\/index.php?rest_route=\/wp\/v2\/posts\/1319","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tomashg.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tomashg.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tomashg.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tomashg.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1319"}],"version-history":[{"count":1,"href":"https:\/\/tomashg.com\/index.php?rest_route=\/wp\/v2\/posts\/1319\/revisions"}],"predecessor-version":[{"id":1320,"href":"https:\/\/tomashg.com\/index.php?rest_route=\/wp\/v2\/posts\/1319\/revisions\/1320"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tomashg.com\/index.php?rest_route=\/wp\/v2\/media\/1321"}],"wp:attachment":[{"href":"https:\/\/tomashg.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1319"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tomashg.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1319"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tomashg.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1319"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}