{"type_number":"12AT7","canonical_url":"https://tubeofile.com/tubes/12AT7","manufacturer":null,"tube_type_key":"small_signal_triode","tube_type_display_name":"Small Signal Triode","base_name":"Noval","description":"High-mu twin triode designed for use as a grounded-grid radio-frequency amplifier or as a combined oscillator and mixer at frequencies below approximately 300 MHz. Two identical triode sections with individual cathode connections. Widely used in audio as a driver and phase inverter.","is_directly_heated":false,"completeness":"high","notes":["Originally designed for VHF/RF use up to 300 MHz in grounded-grid amplifier and oscillator-mixer circuits.","Widely used in audio as a driver tube and phase inverter, particularly in guitar amplifiers.","The 6201/12AT7WA is the ruggedized military version with tighter tolerances.","The 6679 is a GE special-quality version (Special 12AT7) with controlled characteristics.","The 6060 is another special-quality variant (Special 12AT7) for high-frequency service.","No direct Soviet/Russian equivalent exists for the 12AT7.","Can be operated with 6.3V or 12.6V heater supply using the pin 9 center tap.","VT-207 is the US military Signal Corps designation."],"references":["https://frank.pocnet.net/sheets/093/1/12AT7.pdf","https://frank.pocnet.net/sheets/084/e/ECC81.pdf"],"source_urls":{"r_type":"https://www.radiomuseum.org/tubes/tube_12at7.html","tdsl":"https://tdsl.duncanamps.com/show.php?des=12AT7","radiomuseum":"https://www.radiomuseum.org/tubes/tube_12at7.html"},"raw_equivalents":["ECC81","CV455","CV10662","CV8154","CV9859","B309","B152","B739","6201","6060","6679","7492","7728","12AT7WA","12AT7WC","A2900","CV4024","E2157","E81CC","ECC801","ECC801S","M8162","CC81E","CK6201","QA2406","QS2406","8152","8309","8739"],"equivalents":[{"type_number":"A2900","equivalence_type":"direct","notes":null}],"similar":[{"type_number":"12AU7","reason":"Same Noval dual triode pinout but low-mu (mu=17); higher plate current, used as driver/buffer","has_detail_page":true},{"type_number":"12AX7","reason":"Same Noval dual triode pinout but high-mu (mu=100) vs medium-mu (mu=60); lower plate current, higher ra","has_detail_page":true},{"type_number":"12AY7","reason":"Same Noval dual triode pinout, medium-mu (mu=44); popular in early Fender guitar amp preamps","has_detail_page":true},{"type_number":"12AZ7","reason":"Electrically identical (same mu, gm, ra) but higher heater current (225mA series) and higher Vhk_max (200V); designed for series-string TV sets","has_detail_page":true},{"type_number":"5751","reason":"Same Noval dual triode pinout, reduced mu (mu=70); military grade, common lower-gain substitute","has_detail_page":true},{"type_number":"6SL7","reason":"High-mu dual triode (mu=70) but Octal base; similar application as voltage amplifier","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Anode 2 (Triode section 2)","function_code":"a2","notes":null},{"pin_number":"2","function":"Control Grid 2 (Triode section 2)","function_code":"g1_2","notes":null},{"pin_number":"3","function":"Cathode 2 (Triode section 2)","function_code":"k2","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":"Anode 1 (Triode section 1)","function_code":"a1","notes":null},{"pin_number":"7","function":"Control Grid 1 (Triode section 1)","function_code":"g1_1","notes":null},{"pin_number":"8","function":"Cathode 1 (Triode section 1)","function_code":"k1","notes":null},{"pin_number":"9","function":"Heater center tap","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":"Vh","display_name":"Heater Voltage","value":"12.6","numeric_value":"12.6","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"0.3","numeric_value":"0.3","unit":"A","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"0.15","numeric_value":"0.15","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Triode","tube_type_key":"small_signal_triode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"300","numeric_value":"300","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":"Ik_max","display_name":"Cathode Current (max)","value":"15","numeric_value":"15","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"90","numeric_value":"90","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":"250","numeric_value":"250","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-2","numeric_value":"-2","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"10","numeric_value":"10","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"10900","numeric_value":"10900","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"5.5","numeric_value":"5.5","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":"200","numeric_value":"200","unit":"Ω","param_group":"typical_operating"},{"key":"Cgp","display_name":"Grid-to-Plate Capacitance","value":"1.5","numeric_value":"1.5","unit":"pF","param_group":"capacitances"},{"key":"Cin","display_name":"Input Capacitance","value":"2.2","numeric_value":"2.2","unit":"pF","param_group":"capacitances"},{"key":"Cout","display_name":"Output Capacitance","value":"1.2","numeric_value":"1.2","unit":"pF","param_group":"capacitances"}]}],"synced_at":"2026-04-07T12:03:50.281Z"}