{"type_number":"EL12/375","canonical_url":"https://tubeofile.com/tubes/EL12%2F375","manufacturer":"Telefunken","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"Y8A","description":"Factory-selected EL12 output pentode rated for operation up to 375 V anode voltage. Y8A steel base. Telefunken design from 1940, offering almost twice the sensitivity of the AL5. Intended for applications where higher voltage operation was needed beyond the standard EL12's 250 V rating. Predecessor to the EL34.","is_directly_heated":false,"completeness":"high","notes":["The '/375' suffix indicates factory selection for Va_max = 375 V operation.","Cathode-bias only — fixed bias is prohibited, same as all EL12 variants.","Approximately twice the sensitivity of the AL5.","The EL12 spez has a plate top cap — verify whether this variant also has a top cap or base anode.","Brans lists equivalents: 4654(P), 4654K, 4689(P), EL12/325, EL12spez, EL35, EL50, N150."],"references":["https://tdsl.duncanamps.com/show.php?des=EL12/375","https://www.radiomuseum.org/tubes/?tube=EL12/375"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=EL12","radiomuseum":"https://www.radiomuseum.org/tubes/tube_el12375.html"},"raw_equivalents":[],"equivalents":[],"similar":[{"type_number":"EL12","reason":"Standard version rated to 250 V (Philips) / 350 V (Telefunken) — same Y8A base and pinout","has_detail_page":true},{"type_number":"EL12/325","reason":"Lower voltage-selected variant","has_detail_page":false},{"type_number":"EL12/425","reason":"Higher voltage-selected variant","has_detail_page":true},{"type_number":"EL150","reason":"Closely related Telefunken variant — same Y8A base","has_detail_page":true},{"type_number":"EL34","reason":"Successor (1950) with Octal base — not pin-compatible","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Suppressor Grid (internally connected to cathode)","function_code":"g3","notes":null},{"pin_number":"2","function":"Screen Grid","function_code":"g2","notes":null},{"pin_number":"3","function":"Control Grid","function_code":"g1","notes":null},{"pin_number":"4","function":"Cathode","function_code":"k","notes":null},{"pin_number":"5","function":"Heater","function_code":"h","notes":null},{"pin_number":"6","function":"Heater","function_code":"h","notes":null},{"pin_number":"7","function":"Anode","function_code":"a","notes":null},{"pin_number":"8","function":"No Connection","function_code":"nc","notes":null}],"specs":[{"key":"Vh","display_name":"Heater Voltage","value":"6.3","numeric_value":"6.3","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"1.2","numeric_value":"1.2","unit":"A","param_group":"heater"},{"key":"Va_max","display_name":"Anode Voltage (max)","value":"375","numeric_value":"375","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"375","numeric_value":"375","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"18","numeric_value":"18","unit":"W","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-7","numeric_value":"-7","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"72","numeric_value":"72","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"30000","numeric_value":"30000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"15","numeric_value":"15","unit":"mA/V","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"8","numeric_value":"8","unit":"W","param_group":"output"}],"sections":[{"section_number":1,"section_label":"Pentode","tube_type_key":"power_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"375","numeric_value":"375","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"375","numeric_value":"375","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"18","numeric_value":"18","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"2","numeric_value":"2","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"90","numeric_value":"90","unit":"mA","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-7","numeric_value":"-7","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"72","numeric_value":"72","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen 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