{"type_number":"EF814","canonical_url":"https://tubeofile.com/tubes/EF814","manufacturer":"Telefunken","tube_type_key":"ss_pentode","tube_type_display_name":"Small Signal Pentode","base_name":"Noval","description":"Sharp cut-off IF pentode, closely related to the EF184. Used in high-quality microphone preamplifiers and IF amplifier stages in television receivers.","is_directly_heated":false,"completeness":"high","notes":["The EF814 is a Telefunken designation closely related to the EF184. No standalone EF814 datasheet has been found in major tube data repositories; specifications are derived from the EF184 Philips datasheet (January 1970) and cross-referenced with TDSL data.","The EF814K variant was specially selected by David Bock for use in high-end condenser microphones, chosen for characteristics similar to the VF14.","Cathode bias resistor operation is recommended. The tube should not be used in circuits with automatic gain control to ensure good performance with respect to cross-modulation and microphony.","Pin 6 is an internal shield connected to cathode; pin 9 is the metallic envelope coating, also connected internally to cathode."],"references":["https://frank.pocnet.net/sheets/010/e/EF184.pdf","http://tdsl.duncanamps.com/show.php?des=EF184"],"source_urls":{"r_type":null,"tdsl":null,"radiomuseum":"https://www.radiomuseum.org/tubes/tube_ef814.html"},"raw_equivalents":["EF184","6EJ7","CV2195"],"equivalents":[{"type_number":"EF184","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"EF91","reason":"Same Noval base and similar characteristics — the EF814 is a special quality variant of the EF91 family per Brans Vademecum","has_detail_page":true},{"type_number":"Z77","reason":"British designation for the EF91 family — same Noval base and characteristics as EF814","has_detail_page":false}],"pins":[{"pin_number":"1","function":"Suppressor Grid (g3, internally connected to cathode)","function_code":"g3","notes":null},{"pin_number":"2","function":"Control Grid (g1)","function_code":"g1","notes":null},{"pin_number":"3","function":"Cathode","function_code":"k","notes":null},{"pin_number":"4","function":"Heater","function_code":"h","notes":null},{"pin_number":"5","function":"Heater","function_code":"h","notes":null},{"pin_number":"6","function":"Internal Shield (connected to cathode)","function_code":"ia","notes":null},{"pin_number":"7","function":"Anode","function_code":"a","notes":null},{"pin_number":"8","function":"Screen Grid (g2)","function_code":"g2","notes":null},{"pin_number":"9","function":"Metallic Coating / Internal Shield","function_code":"ia","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":"0.3","numeric_value":"0.3","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Pentode","tube_type_key":"ss_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"250","numeric_value":"250","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"250","numeric_value":"250","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"2.5","numeric_value":"2.5","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"0.9","numeric_value":"0.9","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"25","numeric_value":"25","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"150","numeric_value":"150","unit":"V","param_group":"absolute_max"},{"key":"Rg_max","display_name":"Max Grid Resistor","value":"1","numeric_value":"1","unit":"MΩ","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"200","numeric_value":"200","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"200","numeric_value":"200","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-2.5","numeric_value":"-2.5","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"10","numeric_value":"10","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"4.1","numeric_value":"4.1","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"380000","numeric_value":"380000","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":"60","numeric_value":"60","unit":"—","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"140","numeric_value":"140","unit":"Ω","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"0.0055","numeric_value":"0.0055","unit":"pF","param_group":"capacitances"},{"key":"Cgk","display_name":"Grid-to-Cathode Capacitance","value":"10","numeric_value":"10","unit":"pF","param_group":"capacitances"},{"key":"Cak","display_name":"Anode-to-Cathode Capacitance","value":"3","numeric_value":"3","unit":"pF","param_group":"capacitances"},{"key":"Rn","display_name":"Equivalent Noise Resistance","value":"300","numeric_value":"300","unit":"Ω","param_group":"noise_rf"}]},{"section_number":2,"section_label":"Triode Strapped","tube_type_key":"small_signal_triode","specs":[{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"2.5","numeric_value":"2.5","unit":"W","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"200","numeric_value":"200","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-2.5","numeric_value":"-2.5","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"14.1","numeric_value":"14.1","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"3700","numeric_value":"3700","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":"55","numeric_value":"55","unit":"—","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"140","numeric_value":"140","unit":"Ω","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T19:08:02.342Z"}