{"id":863,"date":"2012-12-16T11:07:55","date_gmt":"2012-12-16T11:07:55","guid":{"rendered":"http:\/\/www.bartola.co.uk\/valves\/?p=863"},"modified":"2012-12-16T11:07:55","modified_gmt":"2012-12-16T11:07:55","slug":"improving-the-cx301a-dht-pre-amp","status":"publish","type":"post","link":"https:\/\/www.bartola.co.uk\/valves\/2012\/12\/16\/improving-the-cx301a-dht-pre-amp\/","title":{"rendered":"Improving the CX301a DHT pre-amp"},"content":{"rendered":"<p>An idea discussed with Rod Coleman, Andy Evans and others in DYIAudio forum which still is evolving. The purpose is to increase the output driving capability of this preamp using a cathode-follower stage. A bonus is to provide the filament bias using the cathode-follower valve filaments:<\/p>\n<p><a href=\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2012\/12\/CX301a-DHT-preamp-cathode-follower.png\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"864\" data-permalink=\"https:\/\/www.bartola.co.uk\/valves\/2012\/12\/16\/improving-the-cx301a-dht-pre-amp\/cx301a-dht-preamp-cathode-follower\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2012\/12\/CX301a-DHT-preamp-cathode-follower.png?fit=1504%2C1382&amp;ssl=1\" data-orig-size=\"1504,1382\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"CX301a DHT preamp cathode follower\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2012\/12\/CX301a-DHT-preamp-cathode-follower.png?fit=840%2C771&amp;ssl=1\" class=\"alignleft size-large wp-image-864\" alt=\"CX301a DHT preamp cathode follower\" src=\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2012\/12\/CX301a-DHT-preamp-cathode-follower-1024x940.png?resize=584%2C536\" width=\"584\" height=\"536\" srcset=\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2012\/12\/CX301a-DHT-preamp-cathode-follower.png?resize=1024%2C940&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2012\/12\/CX301a-DHT-preamp-cathode-follower.png?resize=300%2C275&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2012\/12\/CX301a-DHT-preamp-cathode-follower.png?resize=326%2C300&amp;ssl=1 326w, https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2012\/12\/CX301a-DHT-preamp-cathode-follower.png?w=1504&amp;ssl=1 1504w\" sizes=\"auto, (max-width: 584px) 85vw, 584px\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>An idea discussed with Rod Coleman, Andy Evans and others in DYIAudio forum which still is evolving. The purpose is to increase the output driving capability of this preamp using a cathode-follower stage. A bonus is to provide the filament bias using the cathode-follower valve filaments:<\/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_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":[12,156,5],"tags":[10,59,21,47,44,78],"class_list":["post-863","post","type-post","status-publish","format-standard","hentry","category-dht-valves","category-pre-amplifier-valves","category-valves","tag-01a","tag-cx301a","tag-dht-pre-amplifier","tag-dht-preamplifier","tag-gyrator","tag-rod-coleman-regulator"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-dV","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/863","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=863"}],"version-history":[{"count":1,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/863\/revisions"}],"predecessor-version":[{"id":865,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/863\/revisions\/865"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=863"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=863"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=863"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}