{"type_number":"6EM7","canonical_url":"https://tubeofile.com/tubes/6EM7","manufacturer":"RCA","tube_type_key":"compound","tube_type_display_name":"Compound (multi-section)","base_name":"Octal","description":"Dual triode with high-mu and low-mu sections, originally designed for vertical-deflection oscillator and amplifier service in 525-line television receivers","is_directly_heated":false,"completeness":"high","notes":["Dissimilar dual triode: Unit No.1 (high-mu, pins 4/5/6) is a small-signal triode (mu=68, ra=40 kohm); Unit No.2 (low-mu, pins 1/2/3) is a power triode (mu=5.4, ra=750 ohm, Pa_max=10W).","The 6EA7 and 6GL7 are often considered interchangeable with the 6EM7 but have slightly different characteristics — 6EA7: mu 66/5, ra 30k/920 ohm; 6GL7: mu 66/5, ra 30k/780 ohm, heater 1.05A. Many tubes are double-stamped 6EA7/6EM7.","10EM7, 13EM7, and 15EA7 share the same 8BD pinout but have 10V, 13V, and 15V heaters respectively (series-string TV designs). Not interchangeable without heater supply modification.","The bulb becomes hot during operation — adequate ventilation and free circulation of air must be provided.","Popular in DIY audio as a single-tube amplifier: the high-mu section drives the low-mu power section, yielding ~1W SE output into a 4-5 kohm primary."],"references":["https://frank.pocnet.net/sheets/049/6/6EM7.pdf","http://rtellason.com/tubedata/6EM7.PDF"],"source_urls":{"r_type":"https://www.r-type.org/exhib/aas0002.htm","tdsl":"https://tdsl.duncanamps.com/show.php?des=6EM7","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6em7.html"},"raw_equivalents":["6EA7","6GL7","10EM7","13EM7","15EA7","6DA7"],"equivalents":[{"type_number":"6DA7","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"6DE7","reason":"Brans cross-lists — Noval base, different Section 1 characteristics (lower mu). Not a drop-in","has_detail_page":true},{"type_number":"6DN7","reason":"Same 8BD octal basing but very different mu/ra characteristics (mu 22.5/15.4 vs 68/5.4) — not a like-for-like substitute","has_detail_page":true},{"type_number":"6DR7","reason":"Brans cross-lists in same group — Noval (9HF) vs Octal (8BD) base, different pin topology. Similar dissimilar dual triode but different Section 2 characteristics (gm=6.5 vs 7.2 mA/V, ra=925 vs 750 ohms)","has_detail_page":true},{"type_number":"6FD7","reason":"Brans cross-lists in same group — Noval (9HF) vs Octal (8BD) base, different pin topology. Similar Section 1 (mu~64-68) but Section 2 differs (Pa_max 10W vs 10W, gm 7.5 vs 7.2 mA/V)","has_detail_page":true},{"type_number":"6GF7","reason":"Brans cross-lists — similar dissimilar twin triode, Octal base. Verify characteristics before substituting","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Grid (Unit No.2 - Low-Mu Triode)","function_code":"g1_2","notes":null},{"pin_number":"2","function":"Anode (Unit No.2 - Low-Mu Triode)","function_code":"a2","notes":null},{"pin_number":"3","function":"Cathode (Unit No.2 - Low-Mu Triode)","function_code":"k2","notes":null},{"pin_number":"4","function":"Grid (Unit No.1 - High-Mu Triode)","function_code":"g1_1","notes":null},{"pin_number":"5","function":"Anode (Unit No.1 - High-Mu Triode)","function_code":"a1","notes":null},{"pin_number":"6","function":"Cathode (Unit No.1 - High-Mu Triode)","function_code":"k1","notes":null},{"pin_number":"7","function":"Heater","function_code":"h","notes":null},{"pin_number":"8","function":"Heater","function_code":"h","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":"0.925","numeric_value":"0.925","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"High-Mu Triode","tube_type_key":"small_signal_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"330","numeric_value":"330","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"1.5","numeric_value":"1.5","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"22","numeric_value":"22","unit":"mA","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":"2.2","numeric_value":"2.2","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":"-3","numeric_value":"-3","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"1.4","numeric_value":"1.4","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"40000","numeric_value":"40000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"1.6","numeric_value":"1.6","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"68","numeric_value":"68","unit":"—","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"4.8","numeric_value":"4.8","unit":"pF","param_group":"capacitances"},{"key":"Cgk","display_name":"Grid-to-Cathode Capacitance","value":"2.2","numeric_value":"2.2","unit":"pF","param_group":"capacitances"},{"key":"Cak","display_name":"Anode-to-Cathode Capacitance","value":"0.6","numeric_value":"0.6","unit":"pF","param_group":"capacitances"}]},{"section_number":2,"section_label":"Low-Mu Triode","tube_type_key":"power_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"330","numeric_value":"330","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"10","numeric_value":"10","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"50","numeric_value":"50","unit":"mA","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":"2.2","numeric_value":"2.2","unit":"MΩ","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"150","numeric_value":"150","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":"50","numeric_value":"50","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"750","numeric_value":"750","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"7.2","numeric_value":"7.2","unit":"mA/V","param_group":"typical_operating"},{"key":"mu","display_name":"Amplification Factor (μ)","value":"5.4","numeric_value":"5.4","unit":"—","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"10","numeric_value":"10","unit":"pF","param_group":"capacitances"},{"key":"Cgk","display_name":"Grid-to-Cathode Capacitance","value":"7","numeric_value":"7","unit":"pF","param_group":"capacitances"},{"key":"Cak","display_name":"Anode-to-Cathode Capacitance","value":"1.8","numeric_value":"1.8","unit":"pF","param_group":"capacitances"}]}],"synced_at":"2026-04-07T19:03:26.116Z"}