{"type_number":"EL12N","canonical_url":"https://tubeofile.com/tubes/EL12N","manufacturer":"RFT","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"Y8A","description":"Output pentode for push-pull audio amplification; indirectly heated. RFT (Mühlhausen) successor to the EL12spez, eliminating the top-cap anode by bringing all connections to the Y8A base. Electrically identical to EL12spez but with different pin assignments. Rated for 425 V operation.","is_directly_heated":false,"completeness":"high","notes":["The EL12N eliminates the top-cap anode connection of the EL12spez, bringing all electrodes to the Y8A base pins. Pin assignments differ from both the EL12 and EL12spez — none of these three are interchangeable despite sharing the same Y8A base.","Pin layout: pin 1 = g2, pin 2 = g1, pin 3 = k/g3, pin 4 = NC, pin 5 = h, pin 6 = h, pin 7 = NC, pin 8 = anode.","TDSL lists Vg1 = -0.3 V which appears to be a cathode-bias operating point with self-bias resistor.","Triode-strapped data (shared with EL12/EL12spez family from diyAudio measurements): μ = 18, ra = 1.1 kΩ, gm = 15 mA/V.","Widely discussed in DIY audio circles for SE and PP amplifier projects. Known for stability when genuine RFT production.","Some counterfeit or degraded specimens exhibited thermal instability — test before use.","Produced by VEB Röhrenwerk Mühlhausen (East Germany), also made by Tesla and RSD."],"references":["https://www.diyaudio.com/community/threads/el12n-in-hifi.346273/page-2"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=EL12N","radiomuseum":"https://www.radiomuseum.org/tubes/tube_el12n.html"},"raw_equivalents":[],"equivalents":[],"similar":[{"type_number":"EL12","reason":"Same tube family but completely different pin assignments and lower voltage rating (350 V vs 425 V) — not interchangeable","has_detail_page":true},{"type_number":"EL12/425","reason":"Same voltage rating (425 V) and electrically equivalent but different pin assignments on Y8A base — not pin-compatible","has_detail_page":true},{"type_number":"EL12spez","reason":"Electrically equivalent but different pin assignments — anode on pin 8 instead of top cap, g2 on pin 1 instead of pin 8. Not pin-compatible.","has_detail_page":true},{"type_number":"EL150","reason":"Related type with different max ratings — listed as replaceable by Radiomuseum","has_detail_page":true},{"type_number":"EL6","reason":"Electrically similar Philips equivalent but uses B8A base instead of Y8A — not pin-compatible","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Screen Grid (g2)","function_code":"g2","notes":null},{"pin_number":"2","function":"Control Grid (g1)","function_code":"g1","notes":null},{"pin_number":"3","function":"Cathode / Suppressor Grid (internally connected)","function_code":"k","notes":null},{"pin_number":"4","function":"No Connection","function_code":"nc","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":"No Connection","function_code":"nc","notes":null},{"pin_number":"8","function":"Anode","function_code":"a","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"}],"sections":[{"section_number":1,"section_label":"Pentode","tube_type_key":"power_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"425","numeric_value":"425","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"425","numeric_value":"425","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":"2.5","numeric_value":"2.5","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":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"50","numeric_value":"50","unit":"V","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":"mAa","display_name":"Anode Current","value":"72","numeric_value":"72","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"11","numeric_value":"11","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"20000","numeric_value":"20000","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"},{"key":"rl","display_name":"Load Impedance","value":"3500","numeric_value":"3500","unit":"Ω","param_group":"output"}]},{"section_number":2,"section_label":"Triode Strapped","tube_type_key":"power_triode","specs":[{"key":"ra","display_name":"Anode Resistance","value":"1100","numeric_value":"1100","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"15","numeric_value":"15","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"18","numeric_value":"18","unit":"—","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T12:43:09.130Z"}