{"type_number":"EL156","canonical_url":"https://tubeofile.com/tubes/EL156","manufacturer":"Telefunken","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"Magnoval","description":"Power pentode (Endpentode) for audio output stages, series regulators, and industrial applications. Originally developed by Telefunken in 1952 as successor to EL151. Uses German Steel 10-pin (Y10A/Stahl 10) base.","is_directly_heated":false,"completeness":"high","notes":["Uses German Steel 10-pin (Y10A / Stahl 10 / G10A) base, which is not a standard octal, noval, or magnoval socket. Requires a dedicated Y10 socket.","A Magnoval-based variant also exists (EL156 Magnoval) but is not pin-compatible with the original Y10A version.","Max anode dissipation differs by bias type: 50W with cathode (auto) bias, 40W with fixed bias.","Screen grid dissipation limit depends on drive level: 8W at Ug1eff=0, but 12W permissible with speech and music signals.","In triode connection, max combined screen voltage is 500V (vs 450V in pentode mode). Telefunken recommends keeping combined anode+screen dissipation below 35W in triode mode.","A 100 Ohm screen stopper resistor is required before the screen grid in push-pull AB operation.","Pins 3 and 4 are internal connections (beam plates) and must not be connected externally.","Predecessor: EL151. Production period: 1952-1973."],"references":["https://frank.pocnet.net/sheets/128/e/EL156.pdf","https://www.radiomuseum.org/tubes/tube_el156.html"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=EL156","radiomuseum":"https://www.radiomuseum.org/tubes/tube_el156.html"},"raw_equivalents":["EL156A"],"equivalents":[],"similar":[],"pins":[{"pin_number":"1","function":"Heater","function_code":"h","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"Internal Connection (beam plate)","function_code":"ia","notes":null},{"pin_number":"4","function":"Internal Connection (beam plate)","function_code":"ia","notes":null},{"pin_number":"5","function":"Anode","function_code":"a","notes":null},{"pin_number":"6","function":"Screen Grid","function_code":"g2","notes":null},{"pin_number":"7","function":"Control Grid","function_code":"g1","notes":null},{"pin_number":"8","function":"Control Grid","function_code":"g1","notes":null},{"pin_number":"9","function":"Cathode, Suppressor Grid","function_code":"k","notes":null},{"pin_number":"10","function":"Cathode, Suppressor Grid","function_code":"k","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":"1.9","numeric_value":"1.9","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":"800","numeric_value":"800","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"450","numeric_value":"450","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"50","numeric_value":"50","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"12","numeric_value":"12","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"180","numeric_value":"180","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":"Rg_max","display_name":"Max Grid Resistor","value":"0.1","numeric_value":"0.1","unit":"MΩ","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"450","numeric_value":"450","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"280","numeric_value":"280","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-11.6","numeric_value":"-11.6","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"112","numeric_value":"112","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"17","numeric_value":"17","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":"11","numeric_value":"11","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"15","numeric_value":"15","unit":"—","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"90","numeric_value":"90","unit":"Ω","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"24","numeric_value":"24","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"3800","numeric_value":"3800","unit":"Ω","param_group":"output"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"0.5","numeric_value":"0.5","unit":"pF","param_group":"capacitances"},{"key":"Cin","display_name":"Input Capacitance","value":"19","numeric_value":"19","unit":"pF","param_group":"capacitances"},{"key":"Cout","display_name":"Output Capacitance","value":"7.5","numeric_value":"7.5","unit":"pF","param_group":"capacitances"}]},{"section_number":2,"section_label":"Triode Strapped","tube_type_key":"power_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"800","numeric_value":"800","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"50","numeric_value":"50","unit":"W","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"500","numeric_value":"500","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-27.5","numeric_value":"-27.5","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"110","numeric_value":"110","unit":"mA","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"250","numeric_value":"250","unit":"Ω","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"30","numeric_value":"30","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"2800","numeric_value":"2800","unit":"Ω","param_group":"output"}]}],"synced_at":"2026-04-07T19:08:32.688Z"}