{"product_id":"mullard_cv4004_m8137_box_plates","title":"Mullard CV4004 Box Plates (Mitcham, GB)","description":"\u003cdiv\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 14pt; font-family: Arial, sans-serif; color: rgb(42, 99, 58); background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;\"\u003eSoundlumia's Opinion\u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eNo other tubes can deliver vocals like the Blackburn Mullard's, and that's a fact. These ECC83's are extremely hard to find today and are becoming every serious audiophile's darling. Presented here are two lovely Blackburn valves with the old-style Mullard shield logo, which are even more special today.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eThe overall tonality of Mullard ECC83 tubes is warm and lively with a very spacious sound stage. \"Like a warm British jacket of the finest tweed, these glorious tubes have an attractive sweet warmth in their midrange and lower regions.\"  This is how the experts on audiotubes.com describe the sound signature of British-made Mullard tubes. The top end is silky and pleasant and doesn't get rolled off. They retain a fine sense of \"air\" at the top, and the upper midrange is smooth and liquid. These tubes reproduce the human voice, especially female voices, with haunting realism. The British made Mullard tubes are also known to have an attractive sparkle at the top with rich bass...now we know where that \"warm British jacket\" comes from!\u003c\/span\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003c\/span\u003e\u003cbr\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003ctable border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"500\" style=\"border-collapse: collapse; width: 376pt;\"\u003e\n\u003ccolgroup\u003e \u003ccol width=\"64\" span=\"2\" style=\"width: 48pt;\"\u003e \u003ccol width=\"93\" span=\"4\" style=\"mso-width-source: userset; mso-width-alt: 3258; width: 70pt;\"\u003e \u003c\/colgroup\u003e\n\u003ctbody\u003e\n\u003ctr height=\"22\" style=\"height: 16.5pt;\"\u003e\n\u003ctd colspan=\"6\" height=\"22\" class=\"xl73\" width=\"500\" style=\"height: 16.5pt; width: 376pt;\"\u003e\u003cstrong\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif; color: #ff6600;\"\u003e2x Mullard M8137 CV4004 (ECC83+) Box Plates - Mitcham '66 - NOS\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"39\" style=\"mso-height-source: userset; height: 29.0pt;\"\u003e\n\u003ctd colspan=\"2\" rowspan=\"2\" height=\"61\" class=\"xl70\" width=\"128\" style=\"height: 45.5pt; width: 96pt;\"\u003e\n\u003cdiv data-ccp-timestamp=\"1728761131875\"\u003e\u003cstrong\u003eM8137 (1960s)\u003c\/strong\u003e\u003c\/div\u003e\n\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl70\" width=\"186\" style=\"width: 140pt;\"\u003e\u003cstrong\u003eTransconductance (mA\/V)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl71\"\u003e\u003cstrong\u003ePlate Current (mA)\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 16.5pt;\"\u003e\n\u003ctd height=\"22\" class=\"xl72\" style=\"height: 16.5pt;\"\u003e\u003cstrong\u003eTriode 1\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd class=\"xl72\"\u003e\u003cstrong\u003eTriode 2\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd class=\"xl72\"\u003e\u003cstrong\u003eTriode 1\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd class=\"xl72\"\u003e\u003cstrong\u003eTriode 2\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 16.5pt;\"\u003e\n\u003ctd colspan=\"2\" rowspan=\"2\" height=\"44\" class=\"xl65\" width=\"128\" style=\"height: 33.0pt; width: 96pt;\"\u003eTube 1\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt;\"\u003e1.46\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt;\"\u003e1.69\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt;\"\u003e1.15\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt;\"\u003e1.435\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 16.5pt;\"\u003e\n\u003ctd height=\"22\" class=\"xl67\" style=\"height: 16.5pt;\"\u003e91%\u003c\/td\u003e\n\u003ctd class=\"xl67\"\u003e106%\u003c\/td\u003e\n\u003ctd class=\"xl67\"\u003e96%\u003c\/td\u003e\n\u003ctd class=\"xl67\"\u003e120%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 16.5pt;\"\u003e\n\u003ctd colspan=\"2\" rowspan=\"2\" height=\"44\" class=\"xl65\" width=\"128\" style=\"height: 33.0pt; width: 96pt;\"\u003eTube 2\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt;\"\u003e1.81\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt;\"\u003e1.68\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt;\"\u003e1.532\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt;\"\u003e1.292\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 16.5pt;\"\u003e\n\u003ctd height=\"22\" class=\"xl67\" style=\"height: 16.5pt;\"\u003e113%\u003c\/td\u003e\n\u003ctd class=\"xl67\"\u003e105%\u003c\/td\u003e\n\u003ctd class=\"xl67\"\u003e128%\u003c\/td\u003e\n\u003ctd class=\"xl67\"\u003e108%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 16.5pt;\"\u003e\n\u003ctd colspan=\"2\" rowspan=\"2\" height=\"44\" class=\"xl68\" style=\"height: 33.0pt;\"\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl68\"\u003e\u003cstrong\u003eCertification Device\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl68\"\u003e\u003cstrong\u003eCertification Date\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 16.5pt;\"\u003e\n\u003ctd colspan=\"2\" height=\"22\" class=\"xl68\" style=\"height: 16.5pt;\"\u003eRoeTest V11\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl69\"\u003e8\/18\/2024\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"500\" style=\"border-collapse: collapse; width: 376pt; height: 194.194px;\"\u003e\n\u003ccolgroup\u003e \u003ccol width=\"64\" span=\"2\" style=\"width: 48pt;\"\u003e \u003ccol width=\"93\" span=\"4\" style=\"mso-width-source: userset; mso-width-alt: 3258; width: 70pt;\"\u003e \u003c\/colgroup\u003e\n\u003ctbody\u003e\n\u003ctr height=\"22\" style=\"height: 48.5278px;\"\u003e\n\u003ctd colspan=\"6\" height=\"22\" class=\"xl73\" width=\"500\" style=\"height: 48.5278px; width: 376pt;\"\u003e\u003cstrong\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif; color: #ff6600;\"\u003eMullard 6057 CV4004 Box Plates Matched Pair - Mitcham '57 - Same Code - Strong\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"37\" style=\"height: 36.4444px;\"\u003e\n\u003ctd colspan=\"2\" rowspan=\"2\" height=\"59\" class=\"xl70\" width=\"128\" style=\"height: 58.4444px; width: 96pt;\"\u003e\n\u003cdiv data-ccp-timestamp=\"1728761131875\"\u003e\u003cstrong\u003e\"Shark Tooth\"\u003c\/strong\u003e\u003c\/div\u003e\n\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl70\" width=\"186\" style=\"width: 140pt; height: 36.4444px;\"\u003e\u003cstrong\u003eTransconductance (mA\/V)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl71\" style=\"height: 36.4444px;\"\u003e\u003cstrong\u003ePlate Current (mA)\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 22px;\"\u003e\n\u003ctd height=\"22\" class=\"xl72\" style=\"height: 22px;\"\u003e\u003cstrong\u003eTriode 1\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd class=\"xl72\" style=\"height: 22px;\"\u003e\u003cstrong\u003eTriode 2\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd class=\"xl72\" style=\"height: 22px;\"\u003e\u003cstrong\u003eTriode 1\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd class=\"xl72\" style=\"height: 22px;\"\u003e\u003cstrong\u003eTriode 2\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 22.1111px;\"\u003e\n\u003ctd colspan=\"2\" rowspan=\"2\" height=\"44\" class=\"xl65\" width=\"128\" style=\"height: 44.1111px; width: 96pt;\"\u003eTube 1\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt; height: 22.1111px;\"\u003e1.33\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt; height: 22.1111px;\"\u003e1.49\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt; height: 22.1111px;\"\u003e1.12\u003c\/td\u003e\n\u003ctd class=\"xl65\" width=\"93\" style=\"width: 70pt; height: 22.1111px;\"\u003e1.127\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 22px;\"\u003e\n\u003ctd height=\"22\" class=\"xl67\" style=\"height: 22px;\"\u003e83%\u003c\/td\u003e\n\u003ctd class=\"xl67\" style=\"height: 22px;\"\u003e93%\u003c\/td\u003e\n\u003ctd class=\"xl67\" style=\"height: 22px;\"\u003e90%\u003c\/td\u003e\n\u003ctd class=\"xl67\" style=\"height: 22px;\"\u003e90%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 21.1111px;\"\u003e\n\u003ctd colspan=\"2\" rowspan=\"2\" height=\"44\" class=\"xl68\" style=\"height: 43.1111px;\"\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl68\" style=\"height: 21.1111px;\"\u003e\u003cstrong\u003eCertification Device\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl68\" style=\"height: 21.1111px;\"\u003e\u003cstrong\u003eCertification Date\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr height=\"22\" style=\"height: 22px;\"\u003e\n\u003ctd colspan=\"2\" height=\"22\" class=\"xl68\" style=\"height: 22px;\"\u003eRoeTest V11\u003c\/td\u003e\n\u003ctd colspan=\"2\" class=\"xl69\" style=\"height: 22px;\"\u003e9\/26\/2024\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"text-align: start; text-indent: 0px;\"\u003e\n\u003cdiv style=\"orphans: 2; text-align: start; text-indent: 0px;\"\u003e\n\u003cdiv style=\"text-align: start;\" id=\"ds_div\"\u003e\n\u003cdiv style=\"text-align: start;\" id=\"ds_div\"\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0); font-weight: 400;\"\u003e\n\u003cdiv\u003e\n\u003cp\u003e\u003cspan style=\"text-decoration: underline;\"\u003e\u003cspan style=\"color: rgb(219, 118, 17); text-decoration: underline;\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 18.0pt; font-family: 'Arial',sans-serif;\"\u003eM8137 (1960s)\u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cspan style=\"color: rgb(217, 119, 21);\"\u003e\u003cb\u003e***\u003cem\u003eSOLD***\u003c\/em\u003e \u003c\/b\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cspan style=\"color: rgb(217, 119, 21);\"\u003e\u003cb\u003e2x Mullard M8137 CV4004 (ECC83+) Box Plates - Mitcham '66 - NOS\u003c\/b\u003e\u003cstrong\u003e \u003c\/strong\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cstrong\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cspan style=\"color: rgb(217, 119, 21);\"\u003e\u003cspan\u003e$439.85\u003c\/span\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cstrong\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cspan style=\"color: rgb(217, 119, 21);\"\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eProfessional Tube Testing\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003ca name=\"_Hlk169732138\" style=\"color: rgb(0, 0, 0);\"\u003e\u003c\/a\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eThis set was tested and certified by \u003cb\u003eRoeTest V11 Professional Tube Testing System\u003c\/b\u003e with the following result: \u003c\/span\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eTube 1: \u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eMeasured transconductance(GM): 1.46\/1.69 mA\/V - 91%\/106% (100% = 1.6 mA\/V)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eMeasured plate current(IA): 1.15\/1.435 mA - 96%\/120% (100% = 1.2 mA)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eTube 2: \u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eMeasured transconductance(GM): 1.81\/1.68 mA\/V - 113%\/105% (100% = 1.6 mA\/V)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eMeasured plate current(IA): 1.532\/1.292 mA - 128%\/108% (100% = 1.2 mA)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eCurve trace is also included in the original RoeTest report.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eAppearance \u0026amp; Cosmetic condition\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eSilkscreen: 98% - 100% (Immaculate)\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eDate codes:\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e641 R6C4\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e (\u003cb\u003eR = Mitcham, GB, 6 = 1966\u003c\/b\u003e, C = March, 4 = Week 4 of the production month)\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e641 R6D1\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e (\u003cb\u003eR = Mitcham, GB, 6 = 1966\u003c\/b\u003e, D = April, 1 = Week 1 of the production month)\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003ePackaging\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003eNEW \u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003ereproduction Mullard tube boxes.\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e \u003c\/span\u003e\u003c\/p\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003ch4 class=\"MsoNormal\"\u003e\u003cspan style=\"text-decoration: underline;\"\u003e\u003cspan style=\"color: rgb(219, 118, 17); text-decoration: underline;\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 18.0pt; font-family: 'Arial',sans-serif;\"\u003e6057 \"Shark Tooth\" (1950s)\u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/h4\u003e\n\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cspan style=\"color: rgb(217, 119, 21);\"\u003e\u003cb\u003e\u003cspan\u003eMullard 6057 CV4004 Box Plates Matched Pair - Mitcham '57 - Same Code - Strong\u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/span\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cspan style=\"color: rgb(217, 119, 21);\"\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cstrong\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cspan style=\"color: rgb(217, 119, 21);\"\u003e\u003cspan\u003e$443.75\u003c\/span\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cpre style=\"caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;\" data-ccp-timestamp=\"1712184066044\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb style=\"font-family: 'Market Sans', Arial, sans-serif; white-space: normal; color: rgb(42, 99, 58);\"\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eProfessional Tube Testing\u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003cbr\u003e\u003c\/pre\u003e\n\u003cdiv style=\"text-align: start; text-indent: 0px;\"\u003e\n\u003cdiv style=\"orphans: 2; text-align: start; text-indent: 0px;\"\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cdiv style=\"text-align: start;\" id=\"ds_div\"\u003e\n\u003cdiv style=\"color: rgb(0, 0, 0); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; font-family: 'Market Sans', Arial, sans-serif; font-weight: 400;\"\u003e\n\u003cp style=\"background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; vertical-align: baseline;\" class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003ca name=\"_Hlk169732138\" style=\"color: rgb(0, 0, 0);\"\u003e\u003c\/a\u003e\u003cspan style=\"font-size: 14pt; font-family: Arial, sans-serif;\"\u003eThis set was tested and certified by \u003cb\u003eRoeTest V11 Professional Tube Testing System\u003c\/b\u003e with the following result: \u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eTube 1: \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eMeasured transconductance(GM): 1.33\/1.49 mA\/V - 83%\/93% (100% = 1.6 mA\/V)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eMeasured plate current(IA): 1.12\/1.127 mA - 90%\/90% (100% = 1.25 mA)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eTube 2: \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eMeasured transconductance(GM): 1.44\/1.3 mA\/V - 90%\/81% (100% = 1.6 mA\/V)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eMeasured plate current(IA): 1.075\/0.797 mA - 86%\/64% (100% = 1.25 mA)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003c\/span\u003e\u003cbr\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"color: rgb(0, 0, 0); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; font-family: 'Market Sans', Arial, sans-serif; font-weight: 400;\"\u003e\n\u003cspan style=\"font-size: 14.0pt; font-family: 'Arial',sans-serif; mso-fareast-font-family: Aptos; mso-fareast-theme-font: minor-latin; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;\"\u003eCurve trace is also included in the original RoeTest report.\u003c\/span\u003e\u003cbr\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"color: rgb(0, 0, 0); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; font-family: 'Market Sans', Arial, sans-serif; font-weight: 400;\"\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cdiv\u003e\n\u003cdiv style=\"text-align: start;\" id=\"ds_div\"\u003e\n\u003cdiv style=\"text-align: start;\" id=\"ds_div\"\u003e\n\u003cdiv\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0); font-weight: 400;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eAppearance \u0026amp; Cosmetic condition\u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0); font-weight: 400;\"\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0); font-weight: 400;\"\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eSilkscreen: 98% - 100% (Immaculate)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0); font-weight: 400;\"\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0); font-weight: 400;\"\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003eDate codes:\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0); font-weight: 400;\"\u003e\n\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003c\/span\u003e\u003cbr\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0); font-weight: 400;\"\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e641 R7G\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e (\u003cb\u003eR = Mitcham, GB, 7 = 1957\u003c\/b\u003e, G = July)\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e641 R7G\u003c\/span\u003e\u003c\/b\u003e\u003cspan style=\"font-size: 13.0pt; font-family: 'Arial',sans-serif;\"\u003e (\u003cb\u003eR = Mitcham, GB, 7 = 1957\u003c\/b\u003e, G = July)\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal;\"\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cb\u003e\u003cspan\u003ePackaging\u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal;\"\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cb\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0);\"\u003e\u003cspan style=\"font-family: Arial; font-size: large;\"\u003e\u003cb\u003eNEW \u003c\/b\u003ereproduction Mullard tube boxes.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family: 'Market Sans', Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; text-transform: none; word-spacing: 0px; text-decoration-line: none; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); white-space: normal; color: rgb(0, 0, 0); font-weight: 400;\"\u003e\n\u003cp style=\"background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; vertical-align: baseline;\" class=\"MsoNormal\"\u003e \u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cstyle type=\"text\/css\"\u003e\np.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px 'Helvetica Neue'}\n\u003c\/style\u003e\n\u003cstyle type=\"text\/css\"\u003e\np.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 13.0px 'Helvetica Neue'}\n\u003c\/style\u003e","brand":"Mullard","offers":[{"title":"M8137 (1960s)","offer_id":49669535400256,"sku":"266911811794","price":439.85,"currency_code":"USD","in_stock":false},{"title":"6057 \"Shark Tooth\" (1950s)","offer_id":49669535367488,"sku":"266911811793","price":443.75,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0809\/2388\/5888\/files\/DSC_0466.jpg?v=1726031072","url":"https:\/\/www.soundlumia.com\/it\/products\/mullard_cv4004_m8137_box_plates","provider":"Soundlumia","version":"1.0","type":"link"}