International Servicemaster 6HG8 ECF86 Vacuum Tube NOS NIB Transleteronic They are dead quiet when

They are dead quiet when the CD player is paused (I have no preamp) and have excellent frequency response

dark gray rounded plates and excellent flashing

These four US-made 12SC7 tubes tested as follows on our Paul Hart-calibrated TV7/U:

72/76 and 92/90 where minimum (65%) is 50/50 and 100% is 77/77

International Servicemaster 6HG8 ECF86 Vacuum Tube NOS NIB Transleteronic They are dead quiet whenThis new old stock, new in box Japanese International Servicemaster 6HG8 ECF86 tube tested to spec on our Paul Hart calibrated TV7 U. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY SISTER SITE "LOWTECHTWOO" AND OR CALL OR TEXT US AT 202 372 6931 IF YOU DO NOT SEE WHAT YOU NEED OR HAVE ANY QUESTIONS. 1. MOST FORMS OF SHIPPING EXCEPT MEDIA MAIL ARE AUTOMATICALLY INSURED UP TO $100. ETSY PURCHASE