{"type_number":"6BR7","canonical_url":"https://tubeofile.com/tubes/6BR7","manufacturer":"Brimar","tube_type_key":"sharp_cutoff_pentode","tube_type_display_name":"Sharp Cutoff Pentode","base_name":"Noval","description":"Sharp-cutoff low-noise RF pentode on a Noval (B9A) base. Designed for low-noise preamplifier service in audio and instrumentation applications. Indirectly heated.","is_directly_heated":false,"completeness":"high","notes":["The 6BR7 is specifically designed for low-noise microphone and pickup preamplifier applications.","Typical operating conditions at Va=250V, Vg2=100V, Vg1=-3V: Ia=2.1mA, Ig2=0.6mA, Rp=2.5MΩ, Gm=1250 umhos.","Maximum ratings: plate voltage 300V, screen voltage 125V, plate dissipation 1.75W.","The low plate current and high Rp make this tube unsuitable as a general-purpose pentode — it is specifically optimised for low-noise voltage gain."],"references":["https://frank.pocnet.net/sheets/019/6/6BR7.pdf","https://tdsl.duncanamps.com/show.php?des=6BR7"],"source_urls":{"r_type":null,"tdsl":"https://tdsl.duncanamps.com/show.php?des=6BR7","radiomuseum":"https://www.radiomuseum.org/tubes/tube_6br7.html"},"raw_equivalents":["6059","CV5215"],"equivalents":[],"similar":[{"type_number":"6267","reason":"American designation for EF86 — similar function but different pinout","has_detail_page":false},{"type_number":"EF86","reason":"Similar low-noise pentode on Noval base with higher Gm (1.8 vs 1.25 mA/V) — different operating points, not pin-compatible","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Internal Shield","function_code":"is","notes":null},{"pin_number":"2","function":"Anode","function_code":"a","notes":null},{"pin_number":"3","function":"Suppressor Grid (g3)","function_code":"g3","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":"Screen Grid (g2)","function_code":"g2","notes":null},{"pin_number":"7","function":"No Connection","function_code":"nc","notes":null},{"pin_number":"8","function":"Cathode","function_code":"k","notes":null},{"pin_number":"9","function":"Control Grid (g1)","function_code":"g1","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":"0.15","numeric_value":"0.15","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Pentode","tube_type_key":"sharp_cutoff_pentode","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"300","numeric_value":"300","unit":"V","param_group":"absolute_max"},{"key":"Vs_max","display_name":"Screen Voltage (max)","value":"125","numeric_value":"125","unit":"V","param_group":"absolute_max"},{"key":"Pa_max","display_name":"Anode Dissipation (max)","value":"1.75","numeric_value":"1.75","unit":"W","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":"100","numeric_value":"100","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":"2.1","numeric_value":"2.1","unit":"mA","param_group":"typical_operating"},{"key":"mAs","display_name":"Screen Current","value":"0.6","numeric_value":"0.6","unit":"mA","param_group":"typical_operating"},{"key":"ra","display_name":"Anode Resistance","value":"2500000","numeric_value":"2500000","unit":"Ω","param_group":"typical_operating"},{"key":"gm","display_name":"Transconductance","value":"1.25","numeric_value":"1.25","unit":"mA/V","param_group":"typical_operating"}]}],"synced_at":"2026-04-07T12:18:49.702Z"}