{"type_number":"6L6GC","canonical_url":"https://tubeofile.com/tubes/6L6GC","manufacturer":"RCA","tube_type_key":"beam_tetrode","tube_type_display_name":"Beam Tetrode","base_name":"Octal","description":"High-power version of the 6L6 beam tetrode, introduced by RCA in 1960. Features significantly higher ratings than the original 6L6 (Pa_max 30W vs 19W, Va_max 500V vs 360V, Vs_max 450V vs 270V). Widely used in guitar amplifiers and high-fidelity audio equipment. The most popular member of the 6L6 family.","is_directly_heated":false,"completeness":"high","notes":["Data from RCA datasheet dated 8-60. The 6L6GC has substantially higher ratings than the original 6L6: Pa_max 30W vs 19W, Va_max 500V vs 360V, Vs_max 450V vs 270V, Ps_max 5W vs 2.5W.","Pin 1 is not connected on 6-pin base variants; on medium-shell Octal bases pin 1 may connect to an internal shield. Pin 6 has no connection on any variant.","Rg_max of 0.1 MΩ applies to fixed-bias operation. For cathode-bias (self-bias) circuits, up to 0.5 MΩ is permitted.","Triode-strapped data from RCA datasheet page 3 (triode connection, grid No.2 connected to plate). Schlangen (2009) corroborates mu=8, gm=4.7 mA/V, ra=1700 Ω for the 6L6 family.","MIL-HDBK-213A classifies the 6L6GC as a beam power amplifier. Brans Vademecum cross-lists 6L6GC(WGB) with the 6L6 family.","Sams lists KT66 as substitute for 6L6GC, and 6L6GC as substitute for KT66 and DL37."],"references":["https://frank.pocnet.net/sheets/049/6/6L6GC.pdf"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6L6GC","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6l6gc.html"},"raw_equivalents":["6L6","6L6G","6L6GA","6L6GB","6L6WGB","6P3S","6P3S-E","6N3C","CV1947","6P3P"],"equivalents":[{"type_number":"6L6","equivalence_type":"direct","notes":null},{"type_number":"6N3C","equivalence_type":"direct","notes":null},{"type_number":"6P3P","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"5881","reason":"Same pinout but significantly lower max ratings (400V/23W vs 500V/30W) — not safe as drop-in at GC operating limits","has_detail_page":true},{"type_number":"7027A","reason":"Same 6L6 family with same pinout but higher plate and screen voltage ratings (600V vs 500V)","has_detail_page":true},{"type_number":"7581","reason":"Tung-Sol direct replacement for 6L6GC with improved zero-bias characteristics and low-loss base","has_detail_page":true},{"type_number":"EL37","reason":"Sams lists as substitute — Mullard Octal power pentode with similar characteristics but different internal design","has_detail_page":true},{"type_number":"KT66","reason":"Sams lists as mutual substitute — GEC beam tetrode with similar characteristics but different internal construction","has_detail_page":true}],"pins":[{"pin_number":"1","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"Plate","function_code":"a","notes":null},{"pin_number":"4","function":"Screen Grid","function_code":"g2","notes":null},{"pin_number":"5","function":"Control Grid","function_code":"g1","notes":null},{"pin_number":"6","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"7","function":"Heater","function_code":"h","notes":null},{"pin_number":"8","function":"Cathode","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":"0.9","numeric_value":"0.9","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Beam Tetrode","tube_type_key":"beam_tetrode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"500","numeric_value":"500","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":"30","numeric_value":"30","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"5","numeric_value":"5","unit":"W","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"200","numeric_value":"200","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":"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":"-14","numeric_value":"-14","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":"5","numeric_value":"5","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"22500","numeric_value":"22500","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"6.0","numeric_value":"6","unit":"mA/V","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":"4","numeric_value":"4","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"3000","numeric_value":"3000","unit":"Ω","param_group":"output"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"0.6","numeric_value":"0.6","unit":"pF","param_group":"capacitances"},{"key":"Cin","display_name":"Input Capacitance","value":"10","numeric_value":"10","unit":"pF","param_group":"capacitances"},{"key":"Cout","display_name":"Output Capacitance","value":"6.5","numeric_value":"6.5","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":"450","numeric_value":"450","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"30","numeric_value":"30","unit":"W","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":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-20","numeric_value":"-20","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"40","numeric_value":"40","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"1700","numeric_value":"1700","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"4.7","numeric_value":"4.7","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"8","numeric_value":"8","unit":"—","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"1.4","numeric_value":"1.4","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"5000","numeric_value":"5000","unit":"Ω","param_group":"output"}]}],"synced_at":"2026-04-07T19:04:42.938Z"}