{"id":1363,"date":"2013-03-17T09:08:38","date_gmt":"2013-03-17T09:08:38","guid":{"rendered":"http:\/\/www.bartola.co.uk\/valves\/?p=1363"},"modified":"2013-03-17T09:08:38","modified_gmt":"2013-03-17T09:08:38","slug":"a-high-mu-dht-841vt-51","status":"publish","type":"post","link":"https:\/\/www.bartola.co.uk\/valves\/2013\/03\/17\/a-high-mu-dht-841vt-51\/","title":{"rendered":"A high-mu DHT (841\/VT-51)"},"content":{"rendered":"

\"IMG_0332\"<\/a>Thomas Mayer presented in his blog<\/a> a great article about this DHT. A very interesting valve for preamps given its unusual high-mu (circa 30). It could be used in filament bias despite its high filament current needs (see the curves). Ideally choke loaded or IT transformer coupled, I suspect it could perform well with a mu-follower gyrator to provide a low output impedance given its high Ra (for those who are not uncomfortable with some sand assistance \ud83d\ude42 )<\/p>\n

Here are the curves:<\/p>\n

\"VT-51-841SMALL\"<\/a><\/p>\n

I found Ra to be around 20-25K\u03a9, instead of the higher value highlighted by Thomas.<\/p>\n

Here is the SPICE model:Triode 841-Composite<\/a><\/p>\n

\"VT-51<\/a>Which produces a nice set of curves extending to the positive grid current region suggesting an interesting use in A2:<\/p>\n

\"841<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Thomas Mayer presented in his blog a great article about this DHT. A very interesting valve for preamps given its unusual high-mu (circa 30). It could be used in filament bias despite its high filament current needs (see the curves). Ideally choke loaded or IT transformer coupled, I suspect it could perform well with a … Continue reading “A high-mu DHT (841\/VT-51)”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_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}},"categories":[12,67,24],"tags":[362,364,363,360,361],"class_list":["post-1363","post","type-post","status-publish","format-standard","hentry","category-dht-valves","category-thd","category-valve-curve-tracer","tag-362","tag-841-triode-curves","tag-841-tube","tag-vt-51","tag-vt-51-tube"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-lZ","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/1363","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=1363"}],"version-history":[{"count":2,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/1363\/revisions"}],"predecessor-version":[{"id":1370,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/1363\/revisions\/1370"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=1363"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=1363"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=1363"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}