{"id":361,"date":"2020-06-01T19:47:09","date_gmt":"2020-06-01T19:47:09","guid":{"rendered":"https:\/\/izzy-wizzy.com\/?page_id=361"},"modified":"2020-06-12T12:59:18","modified_gmt":"2020-06-12T12:59:18","slug":"813-pp-part-2","status":"publish","type":"page","link":"https:\/\/izzy-wizzy.com\/?page_id=361","title":{"rendered":"813 PP Part 2"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">813 PP Part 2<\/h3>\n\n\n\n<p>After years of trying many designs and failing to get them going properly, in 2018 I decided to have another go at this amplifier and this time do it in public on a forum. <\/p>\n\n\n\n<p>The journey is <a href=\"http:\/\/www.audio-talk.co.uk\/phpBB3\/viewtopic.php?f=11&amp;t=7403&amp;sid=910d8ccd65c020b97cdb0a3436ec1dfa\">documented here<\/a>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"616\" height=\"360\" src=\"https:\/\/izzy-wizzy.com\/wp-content\/uploads\/2020\/06\/813psuht.gif\" alt=\"\" class=\"wp-image-535\"\/><\/figure>\n\n\n\n<p class=\"has-text-align-center\">813 HT PSU<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"344\" height=\"573\" src=\"https:\/\/izzy-wizzy.com\/wp-content\/uploads\/2020\/06\/813psult.gif\" alt=\"\" class=\"wp-image-536\"\/><\/figure>\n\n\n\n<p class=\"has-text-align-center\">813 LT PSU<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"586\" height=\"367\" src=\"https:\/\/izzy-wizzy.com\/wp-content\/uploads\/2020\/06\/813audfin.gif\" alt=\"\" class=\"wp-image-537\"\/><\/figure>\n\n\n\n<p class=\"has-text-align-center\">813 Audio<\/p>\n\n\n\n<p>If I was to make some changes for this design it would be:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>.Use 2 SMPS per valve of half the rating. It equals about the same cost but would perform better. Also use a CMC choke to feed the 813 filaments. This configuration echos <a href=\"http:\/\/www.pmillett.com\/813_se_triode_amps.htm\">Pete Millet&#8217;s solution as in his 813 amplifier<\/a>. It would also enable the 1R current sampling resistors to be in the cathode instead of the anode therefore safer.<\/li><li>Give the driver its own HT supply<\/li><li>Upgrade the bias supply with more filtering<\/li><\/ul>\n\n\n\n<p>After getting to this stage, I am even more impressed by<a href=\"\/?page_id=57#ian813\"> Ian&#8217;s amplifiers here<\/a>. <\/p>\n\n\n\n<p>This proved to be the end of the road for this amplifier which morphed into the <a href=\"https:\/\/izzy-wizzy.com\/?page_id=58\">GM70 here<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>813 PP Part 2 After years of trying many designs and failing to get them going properly, in 2018 I decided to have another go at this amplifier and this time do it in public on a forum. The journey is documented here. 813 HT PSU 813 LT PSU 813 Audio If I was to make some changes for this design it would be: .Use 2 SMPS per valve of<\/p>\n<div class=\"read-more\"><a class=\"btn read-more-btn\" href=\"https:\/\/izzy-wizzy.com\/?page_id=361\">Read More<\/a><\/div>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-361","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/izzy-wizzy.com\/index.php?rest_route=\/wp\/v2\/pages\/361","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/izzy-wizzy.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/izzy-wizzy.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/izzy-wizzy.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/izzy-wizzy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=361"}],"version-history":[{"count":5,"href":"https:\/\/izzy-wizzy.com\/index.php?rest_route=\/wp\/v2\/pages\/361\/revisions"}],"predecessor-version":[{"id":546,"href":"https:\/\/izzy-wizzy.com\/index.php?rest_route=\/wp\/v2\/pages\/361\/revisions\/546"}],"wp:attachment":[{"href":"https:\/\/izzy-wizzy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=361"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}