{"type_number":"7189A","canonical_url":"https://tubeofile.com/tubes/7189A","manufacturer":"GE","tube_type_key":"power_pentode","tube_type_display_name":"Power Pentode","base_name":"Noval","description":"Power pentode, higher-rated version of the EL84/6BQ5. Designed for audio output service with increased anode and screen voltage ratings over the standard 7189. Noval base.","is_directly_heated":false,"completeness":"high","notes":["The 7189A is a selected, higher-rated version of the EL84/6BQ5 family. It can operate at higher plate and screen voltages.","Same Noval base and pin configuration as EL84/6BQ5 — physically interchangeable, but the 7189A is rated for higher voltages.","Used in higher-powered versions of EL84-based amplifiers, such as the Fisher X-100 and Scott 222.","Brans Vademecum lists equivalents including 6BQ5, 6GK6, 8BQ5 — these are functional equivalents at their respective lower ratings, not true replacements at 7189A ratings.","Grid 1 circuit resistance: 0.3 MΩ max for fixed-bias, 1 MΩ max for cathode-bias operation."],"references":["https://tdsl.duncanamps.com/show.php?des=7189A"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=7189A","radiomuseum":"https://www.radiomuseum.org/tubes/tube_7189a.html"},"raw_equivalents":[],"equivalents":[],"similar":[{"type_number":"6BQ5","reason":"Same tube as EL84 — same pinout, lower ratings than 7189A","has_detail_page":false},{"type_number":"6GK6","reason":"Similar power pentode but different Noval pinout — not a drop-in","has_detail_page":true},{"type_number":"7189","reason":"Lower-rated version with same Noval base and pinout — can substitute in circuits within 7189 ratings","has_detail_page":false},{"type_number":"EL84","reason":"Same Noval base and pinout but lower max ratings — the 7189A has higher Va_max and Vs_max. An EL84 can substitute at reduced ratings.","has_detail_page":true}],"pins":[{"pin_number":"1","function":"No Connection","function_code":"nc","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":"No Connection","function_code":"nc","notes":null},{"pin_number":"7","function":"Anode","function_code":"a","notes":null},{"pin_number":"8","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"9","function":"Screen Grid (g2)","function_code":"g2","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":"0.76","numeric_value":"0.76","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Power Pentode","tube_type_key":"power_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"400","numeric_value":"400","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"325","numeric_value":"325","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"12","numeric_value":"12","unit":"W","param_group":"absolute_max"},{"key":"Ps_max","display_name":"Screen Dissipation (max)","value":"2.0","numeric_value":"2","unit":"W","param_group":"absolute_max"},{"key":"Ik_max","display_name":"Cathode Current (max)","value":"65","numeric_value":"65","unit":"mA","param_group":"absolute_max"},{"key":"Vhk_max","display_name":"Heater-to-Cathode Voltage (max)","value":"100","numeric_value":"100","unit":"V","param_group":"absolute_max"},{"key":"Va","display_name":"Anode Voltage (typical)","value":"300","numeric_value":"300","unit":"V","param_group":"typical_operating"},{"key":"Vs","display_name":"Screen Voltage (typical)","value":"300","numeric_value":"300","unit":"V","param_group":"typical_operating"},{"key":"Vg","display_name":"Grid 1 Bias Voltage","value":"-9.5","numeric_value":"-9.5","unit":"V","param_group":"typical_operating"},{"key":"mAa","display_name":"Anode Current","value":"48","numeric_value":"48","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"5.5","numeric_value":"5.5","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"38000","numeric_value":"38000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"11.3","numeric_value":"11.3","unit":"mA/V","param_group":"typical_operating"},{"key":"Pout","display_name":"Output Power","value":"6.5","numeric_value":"6.5","unit":"W","param_group":"output"},{"key":"rl","display_name":"Load Impedance","value":"3800","numeric_value":"3800","unit":"Ω","param_group":"output"}]}],"synced_at":"2026-04-07T12:30:56.539Z"}