[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-672609-105":59,"doc-detail-672609-en":129},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":122,"head_meta":124,"extra_data":126,"updated_unix":128},105,"en","the-tradition-a-triode-odyssey","The Tradition - A Triode Odyssey","","The Tradition describes a multi-year team effort to design a high-quality single-ended triode power amplifier focused on subjective musical satisfaction and maximum technical performance. After limited tube-amp availability changed market conditions in the late 1980s, the team set amplifier criteria emphasizing few stages, high output power, low distortion without feedback, wide bandwidth, and triode-only operation. The GM-70 output tube, Class-A2 operation, and a transformer-coupled driver derived from GEC design principles are used, with an initial version later evaluated by listening 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design criteria guided The Tradition amplifier project?","Question",{"text":111,"@type":112},"The team targeted few stages to reduce distortion, high output power, low distortion without feedback, wide bandwidth, and triode-only operation.","Answer",{"name":114,"@type":109,"acceptedAnswer":115},"Why was the Russian GM-70 chosen as the output tube?",{"text":116,"@type":112},"The GM-70 was selected because it could deliver about 30W using classic recipes and offered favorable power and low distortion reported in a late-1990s vacuum tube context.",{"name":118,"@type":109,"acceptedAnswer":119},"What approach did the team use for the first version’s Class-A2 drive?",{"text":120,"@type":112},"The design used a cathode-follower-style driver with a coupling transformer to provide very low output impedance needed to drive the GM-70 in Class-A2.","https://schema.org",{"og:url":83,"og:type":123,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":125,"canonical":83},"index,follow",{"doc_id":127,"site_id":62},672609,1793600962,{"code":4,"msg":5,"data":130},{"doc_id":127,"user_id":131,"nickname":92,"user_avatar":132,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":67,"doc_content":133,"file_id":134,"file_url":135,"file_type":136,"file_size":137,"view_count":8,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":39,"language":138,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":139,"faqs":140,"seo_title":141,"seo_description":67,"update_tm":128,"read_time":46},34359740700684,"https://ap-avatar.wpscdn.com/avatar/1f400023980c374ae676?_k=1777273430885731487","# The Tradition:A Triode Odyssey\n\nThis team effort,which spanned several years,led to the development of a high-quality single-endedpower amp.  \nBY ISTVÁN BRI  \nastern Europe can look back on along tradition of tube manufac-turing.I am sure all tube fans arefamiliar with the names Tesla,RFT,Ei,andTungsram.All of these manufacturers pro-duced receiving and transmitting tubesand sold them all over the world.Lessknown is that tube-amplifier manufactur-ing has been relatively insignificant com-pared to the number of tubes produced.  \nAlso,the market for such amplifierswas very limited until the politicalchange towards the end of the 80s.Theopening up of the free marketplacebrought all sorts of tube amps into thismarket,causing total confusion amongtube fans.My friends and I have followedthis development,but could not find re-ally good-quality amplifiers.So back inSeptember 1997 we decided to design the“ultimate”SE power amplifier(Photo 1).  \nPX25 were not considered at all becauseof nonavailability.)By chance I found theRussian GM-70,which,with its 125Wanode dissipation and large graphiteanode,looked very exciting to the team(Photo 2).  \nOur team quickly agreed on who wasto do what,and we went to work.Broadlyspeaking,our goal was to design an am-plifier that would provide the best musi-cal satisfaction based on subjective lis-tening.However,we also wished it toachieve maximum technical perfor-mance.This might sound simple,but therealization was anything but.  \nWe decided to use the GM-70 as theoutput tube,because it could easily pro-duce 30W using classic recipes.(Weknew that Western Electric was preparingto produce the 212E/308A triode,butwith its 275W dissipation it was not con-sidered appropriate for this project.)Ap-parently our choice was a good one,since the GM-70 came out on top of thelist in terms of power and low distortionin a'98 article in Vacuum Tube Valley.Mr.Atwood called it“a killer tube with low  \n## AMPLIFIER CRITERIA\n\nWe started looking at the topology of theamplifier,and set up the following criteria:  \n1.A minimum number of stages,on theprinciple that fewer stages produce lessdistortion;  \n## ABOUT THE AUTHOR\n\nIstván Ben,bom in the nothem part ol Hungary,star-ed to tirker with semiconductors when he was 16 yearsold.In 1983 he eamed a degree in mechanical engneering.and worked in various design and producionjobs in a large machine factory forseven years.In 1990he changed direcion and was employed in a truckingcompany,doing logistics.He started his company,NHC.Brenners,in 1993 andis stl blaming Emo Bor-bely for geting him involved with tubes.Today.he runsa sucCesslul tube business and enjoys designing tubeamps with his triends.He is maried and has two sons.who,he says,\"thank God,are not yet interested intubes.Hisemal addressis brenners@elender hu  \n2.Relatively high output power;  \n3.Low distortion without feedback;  \n4.Wide bandwidth;and  \n5.The use only of triodes.  \nBecause of the expected high power,we discarded the 2A3/6B4Gand the 300Bfamily of tubes right from the start.How-ever,we seriously considered the211/845 group with 75/100W anode dis-sipation.(The esoteric types such as the  \nPHOT02:The GM-70 tube.  \ndistortion and high power.\"  \nThe GM-70 is an excellent triode foraudio use.It has 1,500V maximum anodevoltage and 125W anode dissipation,a mu of 7,and a transconductanceof 5.9mA/V.The only disadvantage isits high filament dissipation of 70W(20V/3.5A).The anode and grid charac-teristics are shown in Fig.1.  \n## FIRST VERSION\n\nFigure la suggests using the tube withzero bias and grid current in Class-A2mode instead of classical Class-A1.Wedecided to try it with 500V anode voltagein Class-A2,with a load impedance of  \n50 GLASS AUDIO 6/00  \napproximately 3kΩ.The problem with A2is driving the tube during the positivehalf-cycle,which requires about 7Wclean drive without distortion.We took adeep breath and settled down to studyA2 circuitry.  \nThe solution came from the GECbook,An Approach to Audio Frequency Am","cbCainwVFJLLk39d","https://ap.wps.com/l/cbCainwVFJLLk39d","pdf",2019499,"English","# AMPLIFIER CRITERIA\n# ABOUT THE AUTHOR\n# FIRST VERSION","[{\"question\":\"What design criteria guided The Tradition amplifier project?\",\"answer\":\"The team targeted few stages to reduce distortion, high output power, low distortion without feedback, wide bandwidth, and triode-only operation.\"},{\"question\":\"Why was the Russian GM-70 chosen as the output tube?\",\"answer\":\"The GM-70 was selected because it could deliver about 30W using classic recipes and offered favorable power and low distortion reported in a late-1990s vacuum tube context.\"},{\"question\":\"What approach did the team use for the first version’s Class-A2 drive?\",\"answer\":\"The design used a cathode-follower-style driver with a coupling transformer to provide very low output impedance needed to drive the GM-70 in Class-A2.\"}]","The Tradition - A Triode Odyssey | PDF"]