![\"\"](\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2016\/12\/01a-Universal-HT-Supply-V01.png\")
<\/a><\/p>\nThe transformer is a 250-0-250V \/ 50VA with an output current of 60mA. It has two windings for 6.3V AC heaters, but you only need one. Here<\/a> is a great choice from a recommended seller. <\/p>\n The valve rectifier is a double-diode damper. Of course you can use some other options, but I like the sound of them. Here are some you might want to consider in your build:<\/p>\n For the indirectly heated diodes, it will be better to connect one end of the filaments to the cathode. <\/p>\n The chokes are commonly available. These are from Hammond (155J<\/a>) and have 15H @ 30mA. The downside is the high resistance, over 1k\u03a9. This isn’t an issue here as the current consumption is low so the voltage drop is minimal. With a choke input supply you need a minimum current to operate. In this case is about 15-16mA so a bleeder resistor is needed (29k\u03a9 5W wire wound) . <\/p>\n C1 serves to equalise the output voltage. It pushes the supply to operate a bit more like cap-input (hybrid) by increasing the output voltage. I use it to tune the output voltage to 200V. <\/p>\n C2 and C3 are classic motor run capacitors. I personally use ASC Oil ones 450VAC rated. You can choose what you can get hold. You can use any good quality film capacitors. I like the WIMA DC-LINK ones, they are great.<\/p>\n The output ripple is about 7mV. This isn’t a problem as the gyrator<\/a> load has a very high supply rejection (PSRR) so no need to go crazy on this. If you <\/p>\n The design is so simple that anyone should be able to build this easily. <\/p>\n Hope it works for you.<\/p>\n Merry Christmas!<\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" Introduction I received many requests throughout this year of folks building the 01a preamp (Gen2) asking for advice on the HT supply design. Well, I have my own incarnation which serves multiple purposes as is a shared supply, therefore isn’t useful to anyone. My friend Andy Evans came up with a supply using available components. … Continue reading “01a Preamp (Gen2) Universal HT Supply”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[911,159,156,5],"tags":[309,653,971,973,974,975,248,970,972,44,875],"class_list":["post-6091","post","type-post","status-publish","format-standard","hentry","category-gyrator-pcb","category-power-supplies","category-pre-amplifier-valves","category-valves","tag-01a-preamp","tag-01a-preamp-gen2","tag-6by5g","tag-6c4p-ev","tag-az1","tag-az11","tag-cx-301a","tag-ey-91","tag-ez-80","tag-gyrator","tag-gyrator-pcb"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-1Af","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/6091","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/comments?post=6091"}],"version-history":[{"count":2,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/6091\/revisions"}],"predecessor-version":[{"id":6094,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/6091\/revisions\/6094"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=6091"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=6091"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=6091"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n