{"type_number":"6M6G","canonical_url":"https://tubeofile.com/tubes/6M6G","manufacturer":"Mullard","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"Octal","description":"High-sensitivity output pentode for use in A.C. mains-operated equipment. Designed for audio output stages in domestic radio receivers. Capable of 4 W single-ended Class A or 8.2 W push-pull. Also known as EL33; introduced by Mullard in 1938.","is_directly_heated":false,"completeness":"high","notes":["The Mullard datasheet specifies a maximum supply voltage (Va(b1)) of 550 V, but a maximum anode voltage of 250 V. This means the tube can operate in circuits with HT rails up to 550 V provided the actual anode voltage does not exceed 250 V.","KT61 is functionally similar but is a beam tetrode rather than a true pentode; pin-compatible on octal base.","Grid resistor max is 1.0 MOhm (cathode bias). The datasheet also specifies Rh-k max = 5.0 kOhm.","Sams Substitution Handbook lists 6AG6G as a substitute for 6M6G in parallel-filament circuits only."],"references":["https://frank.pocnet.net/sheets/129/e/EL33.pdf","https://tdsl.duncanamps.com/show.php?des=EL33"],"source_urls":{"r_type":"http://www.r-type.org/exhib/aad0112.htm","tdsl":"https://tdsl.duncanamps.com/show.php?des=6M6G","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6m6g.html"},"raw_equivalents":["EL33","6M6","6M6GT","6AG6G","KT61","N147","CV2938","BVA266","PP6BG"],"equivalents":[],"similar":[],"pins":[{"pin_number":"1","function":"No Connection (metallisation/shell)","function_code":"nc","notes":null},{"pin_number":"2","function":"Heater","function_code":"h","notes":null},{"pin_number":"3","function":"Anode","function_code":"a","notes":null},{"pin_number":"4","function":"Screen Grid (g2)","function_code":"g2","notes":null},{"pin_number":"5","function":"Control Grid (g1)","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 and Suppressor Grid (g3)","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":"Pentode","tube_type_key":"power_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":"275","numeric_value":"275","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"9.0","numeric_value":"9","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":"55","numeric_value":"55","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":"1.0","numeric_value":"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":"-6.0","numeric_value":"-6","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"36","numeric_value":"36","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"4.0","numeric_value":"4","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"50000","numeric_value":"50000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"9.0","numeric_value":"9","unit":"mA/V","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"150","numeric_value":"150","unit":"Ω","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"4.0","numeric_value":"4","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"7000","numeric_value":"7000","unit":"Ω","param_group":"output"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"1.0","numeric_value":"1","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":"250","numeric_value":"250","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":"Vg","display_name":"Grid 1 Bias Voltage","value":"-8.5","numeric_value":"-8.5","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"20","numeric_value":"20","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"3000","numeric_value":"3000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"6.5","numeric_value":"6.5","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"20","numeric_value":"20","unit":"—","param_group":"typical_operating"},{"key":"Rk","display_name":"Cathode Resistor (self-bias)","value":"425","numeric_value":"425","unit":"Ω","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"1.1","numeric_value":"1.1","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"7000","numeric_value":"7000","unit":"Ω","param_group":"output"}]}],"synced_at":"2026-04-07T12:26:36.328Z"}