![\"\"](\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2023\/03\/aaa1539.jpg?resize=361%2C626&ssl=1\")
Here are the pentode curves at different screen voltages with the matching model:<\/p>\n\n\n\n
<\/p>\n\n\n
![\"\"](\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2023\/03\/GU50-150V.png?ssl=1\")
<\/a><\/a><\/a><\/a>Here are the models for you to use:<\/p>\n\n\n\n
***************************************************\n.SUBCKT GU50-pentode-300V 1 2 3 4 ; A G2 G1 C;\n* Extract V3.000\n* Model created: 4-Jun-2016\n* Version 2\n*\n* Curve tracing and model by Ale Moglia (valves@bartola.co.uk)\n* (c) 2016 Bartola Valves\n* www.bartola.co.uk\/valves\n*\n* Derk Model\n*\nX1 1 2 3 4 BTetrodeD MU= 6.26 EX=1.296 kG1= 380.1 KP= 22.3 kVB = 437.3 kG2=92411.5\n+Sc=.81E+01 ap= .100 w= 0. nu= .00 lam= 39.4\n+ Ookg1mOokG2=.262E-02 Aokg1=.99E-06 alkg1palskg2=.262E-02 be= .080 als=173.46 RGI=2000\n+ CCG1=13.0P CCG2 = 0.0p CPG1 = 0.0p CG1G2 = 0.1p CCP=10.0P ;\n.ENDS\n\n****************************************************\n.SUBCKT BTetrodeD 1 2 3 4; A G2 G1 C\n*\n* NOTE: LOG(x) is base e LOG or natural logarithm.\n* For some Spice versions, e.g. MicroCap, this has to be changed to LN(x).\n*\nRE1 7 0 1MEG ; DUMMY SO NODE 7 HAS 2 CONNECTIONS\nE1 7 0 VALUE=\n+{V(2,4)\/KP*LOG(1+EXP(KP*(1\/MU+V(3,4)\/SQRT(KVB+V(2,4)*V(2,4)))))}\nE2 8 0 VALUE = {Ookg1mOokG2 + Aokg1*V(1,4) - alkg1palskg2\/(1 + be*V(1,4))}\nE3 9 0 VALUE = {Sc\/kG2*V(1,4)*(1+tanh(-ap*(V(1,4)-V(2,4)\/lam+w+nu*V(3,4))))}\nG1 1 4 VALUE = {0.5*(PWR(V(7),EX)+PWRS(V(7),EX))*(V(8)-V(9))}\nG2 2 4 VALUE = {0.5*(PWR(V(7),EX)+PWRS(V(7),EX))\/KG2 * (1+ als\/(1+be*V(1,4)))}\nRCP 1 4 1G ; FOR CONVERGENCE\tA - C\nC1 3 4 {CCG1} ; CATHODE-GRID 1\tC - G1\nC4 2 4 {CCG2} ; CATHODE-GRID 2\tC - G2\nC5 2 3 {CG1G2} ; GRID 1 -GRID 2\tG1 - G2\nC2 1 3 {CPG1} ; GRID 1-PLATE\tG1 - A\nC3 1 4 {CCP} ; CATHODE-PLATE\tA - C\nR1 3 5 {RGI} ; FOR GRID CURRENT\tG1 - 5\nD3 5 4 DX ; FOR GRID CURRENT\t5 - C\n.MODEL DX D(IS=1N RS=1 CJO=10PF TT=1N)\n.ENDS BTetrodeD\n<\/code><\/pre>\n\n\n\nAnd here is the triode model:<\/p>\n\n\n\n
****************************************************\n.SUBCKT GU50-triode 1 2 3; A G C;\n* Extract V3.000\n* Model created: 4-Jun-2016\n*\n*\n* Curve tracing and model by Ale Moglia (valves@bartola.co.uk)\n* (c) 2016 Bartola Valves\n* www.bartola.co.uk\/valves\n*\nX1 1 2 3 TriodeK MU= 6.18 EX=1.380 KG1= 448.2 KP= 22.3 KVB= 700. RGI=2000\n+ CCG=0.0P CGP=0.0P CCP=0.0P ;\n.ENDS\n\n****************************************************\n.SUBCKT TriodeK 1 2 3; A G C\n*\n* NOTE: LOG(x) is base e LOG or natural logarithm.\n* For some Spice versions, e.g. MicroCap, this has to be changed to LN(x).\n*\nE1 7 0 VALUE=\n+{V(1,3)\/KP*LOG(1+EXP(KP*(1\/MU+V(2,3)\/SQRT(KVB+V(1,3)*V(1,3)))))}\nRE1 7 0 1G\nG1 1 3 VALUE={0.5*(PWR(V(7),EX)+PWRS(V(7),EX))\/KG1}\nRCP 1 3 1G ; TO AVOID FLOATING NODES IN MU-FOLLOWER\nC1 2 3 {CCG} ; CATHODE-GRID\nC2 2 1 {CGP} ; GRID-PLATE\nC3 1 3 {CCP} ; CATHODE-PLATE\nD3 5 3 DX ; FOR GRID CURRENT\nR1 2 5 {RGI} ; FOR GRID CURRENT\n.MODEL DX D(IS=1N RS=1 CJO=10PF TT=1N)\n.ENDS TriodeK\n<\/code><\/pre>\n\n\n\nYou can download the files from here:<\/p>\n\n\n\n
GU50-pentode-300V<\/a>Download<\/a><\/div>\n\n\n\nGU50-triode<\/a>DOWNLOAD<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"It’s been a while indeed. Mostly busy with my day job and family. However, spare time is dedicated to synthesisers – I’m designing and building modules for Eurorack – and playing and listening to music. I’ve been asked about the GU-50 triode curves. I have misplaced them, however I have something even better to share … Continue reading “GU-50 SPICE Model”<\/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_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":[24,5],"tags":[191,1450,1451,1454,1455,1452,1453],"class_list":["post-11107","post","type-post","status-publish","format-standard","hentry","category-valve-curve-tracer","category-valves","tag-gu-50","tag-gu-50-curves","tag-gu-50-spice-model","tag-gu-50-tube","tag-gu-50-valve","tag-gu50-spice-model","tag-gu50-tube"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-2T9","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/11107","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=11107"}],"version-history":[{"count":4,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/11107\/revisions"}],"predecessor-version":[{"id":11118,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/11107\/revisions\/11118"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=11107"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=11107"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=11107"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}