ACTUAL FEEDBACK ABOUT TUBEMUSEUM TUBES! FeedbackFromWhenFast shipping. Great tube. You made a new customer.Buyer: foremmet ( 3 )  During past month Exemplary Testing EI ECC83 12AX7 SMOOTH-PLATE AMPLITREX TEST 1700/1700 1600/1600 (#231754082369)US $89.95 EACH TUBEFeedbackFromLefttube perfect, thank you.Buyer: gheorghe1051 ( 27)   Exemplary Testing JAN Military RCA 5751 BLACK-PLATE 12AX7 AMPLITREX TESTED TUBE (#291262098065)…"Dear Tube Museum,HII received this morning the last tube ordered and i just have to test it. I just want to tell you your tubes are really beautiful and in superb condition! How do you find a lot of tubes like this and in this perfect condition, where can you find it and how have you got a lot of it, it's really exceptional on the net to find somebody who sale as tubes and so perfect, it's a pleasure to see this beautiful collection!!!Thanks a lot for all ...Best regards.Alex."…Great 5751 tube perfect for my Bellari ha540-fast shipping & great packingBuyer: clocksavant ( 454)  1962 RCA 5751 MUSEUM CERTIFIED AMPLITREX TUBE 1100/1000 low-noise 12AX7 SUB (#231134955661) Perfect!!! Wonderful!!! Awesome!!! Definitely the best!!! ***** five stars ***** hardos174 ( 235)    Exemplary Testing 1962 RCA 5751 12AX7 MUSEUM CERTIFIED AMPLITREX TUBE 100/100 (#291003724204) Perfect!!! Wonderful!!! Awesome!!! Definitely the best!!! ***** five stars ***** hardos174 ( 235)    RCA 5751 12AX7 ECC83 MUSEUM CERTIFIED AMPLITREX TESTED TUBE 1962 USA 130%/120% ! (#291042875850)  Visit this seller's eBay Store!  TubeMuseum THIS LISTING HAS BEEN UPGRADED FROM SINGLE TUBES TO THE LAST MATCHED PAIRSPRICE IS for the MATCHED PAIR!BID 1 FOR THE PAIR!NOS ELEKTRONSKA INDUSTRIJAACTUAL PICTURE OF "PAIR # 1" - PRICE IS FOR THE PAIR! (SOLD! 07/18/20)12AX7 Special QualityLONG "SMOOTH" PLATES1961 NIS YUGOSLAVIA ECC83/12AX7 MATCHED PAIRLONG 17mm SMOOTH-PLATES!TELEFUNKEN SMOOTH versus ELEKTRONSKA NIS FACTORY COMPARISONTHESE WONDERFUL SOUNDING LONG-PLATE TUBES WERE LABELLED UNDER DIFFERENT BRANDS, OFFERED ARE THE TUBES LABELLED "ECC-83 / 12AX7" WITH THE EI NIS YUGOSLAVIA ORIGINAL BOXES.IDENTICLE "SMOOTH-PLATE" INNER-ENGINEERING. BOTH HAVE STAPLED 19mm SMOOTH LONG-PLATES, TELEFUNKEN STAPLED THEM ON THE OUTSIDE where ELEKTRONSKA STAPLED THEM ON THE INSIDE.  LOOKS LIKE "TWINS"!Question:  In your professional opinion do you think this would be a great tube for a Marshall guitar amplifier? I have heard that prewar Eis are outstanding in this regard. The word is that they have the smoothness of Telefunkens but with more liveliness and character. Thanks!Answer: I don't recommend TELEFUNKEN for Marshall guitar amps. For audio systems yes, the TF smooth-plate is very nice, but for any guitar amp the Telefunken is too neutral and dull.I agree with your prewar tone / performance analysis of the EI.also,    ...(They) are awesome tubes.......big, bold, rich, detailed, crisp, not for the faint of heart.........Those are the tubes I run in my superlead, they are the best sounding tubes I have tried in my marshall and I have a large stock of NOS of quite a few different brands.........Mike Z. from Dr Z. said the pre-war Ei is his favourite preamp tube.....Watch these tubes in action here:https://www.youtube.com/watch?v=0mIeM5vbqEUSIMILIAR TO TELEFUNKEN SMOOTH-PLATE ENGINEERING - ONLY BETTER SOUNDING IN A GUITAR AMPL@@K TELEFUNKEN vs. ELEKTROSINKI SMOOTHPLATE COMPARISONSAME LONG-SMOOTH-PLATES as Telefunken ECC83 SMOOTH PLATES with minor differences so as not to infringe on German Copyright lawsBID 1 FOR THE PAIR!ex·em·pla·ry 12AX7 igˈzemplərē/ adjective:   serving as a desirable 12AX7 tube; representing the best of its kind.   How many times have you purchased what you read advertised as a balanced and matched-triode tube on eBay and have received mismatched or marginal tubes? Well, get rid of those! Here are the HIGHEST QUALITY AMPLITREX DIGITALLY TESTED ECC83/12AX7 tube that will end your search for the Top Quality you would expect from a Premium tube in your ultimate HI-FI AMPLIFIER or Musical Amplification system.  NOS TUBE MUSEUM QUALITY ECC83/12AX7  VERY QUIET PLATINUM LOW-NOISE SELECTED  MUSEUM-CERTIFIED  AMPLITREX-TESTED 12AX7 = ECC83BID 1 FOR THE PAIR! ACTUAL PICTURE OF "PAIR # 1" - PRICE IS FOR THE PAIR!TUBES COME IN ELECTRONSKA ORIGINAL BOXES!SAME LONG-SMOOTH-PLATES as Telefunken ECC83 SMOOTH PLATESCERTIFIED ULTRA-LOW-NOISE SPECIMENSBEST and QUIETEST TUBES from ORIGINAL NIS FACTORY in the 1960's SIMPLY the PERFECT REFERENCE 12AX7 AMPLITREX TESTED TUBES BY WHICH ALL OTHER ECC83's CAN BE MEASURED BY!   TubeMuseum tested tubes takes the guesswork out of the process of selection delivering you the best Audio tubes that there possibly can be. ACTUAL TEST RESULTSzero (0) Heater-to-Cathode leakage & zero (0) mA Gas! The Best!BID 1 FOR THE PAIR!VERY QUIET PLATINUM LOW-NOISETRANSCONDUCTANCE (GM): PAIR 1: (SOLD! 07/18/20)Tube 1: 1,700/1,500Tube 2: 1,600/1,400PAIR 1 has identical print (pics 1 -4) and the date codes in the glass are the same and identical @1B and @1B = 1961PAIR 2: (AVAILABLE)ACTUAL PICTURE OF "PAIR # 2" - PRICE IS FOR THE PAIR!Tube 1: 2,000/1,600Tube 2: 1,800/1,800PAIR 2 has a little different logo (PICS 10, 11, 12) however, the date codes in the glass are the same and identical @1B and @1B = 1961WITH STRONGER GM (mA/V) transconductance.Perfect NOS Excellent Performance1.60/1.60mA/V (1600/1600 GM) = 100% AMPLITREX Recommended uMhos  = 100%1,250/1,250mA/V = 100% HICKOK Recommended uMhos  = 100%SAME LONG-SMOOTH-PLATES as Telefunken ECC83 SMOOTH PLATES MUSEUM-CERTIFIED ex·em·pla·ry 12AX7A igˈzemplərē/ adjective serving as a desirable 12AX7 tube; representing the best of its kind. AMPLITREX-TESTED NOS Excellent performance, liquid smooth highs, SMOOTH-Tone WOW the PERFECT LOW-NOISE tone-solution   TESTED AT REAL-WORLD POWER LEVELS ON AMPLITREX AT-1000 Tested on Amplitrex AT1000 Digital Tube Test System This tube is known for excellent performance, smooth highs, outstanding 3-D holographic soundstage, lots of open-air, inner detail, and overall perfect resolution and balanced sound. 12AX7 Substitutes Close or identical 12AX7A Different rating or performance 12AX7, 12AX7A, 12AX7R, 12AX7S, 12AX7WA, 5751WA, 6057, 6681, 6L13, 7025, 7382, 7494, 7729, B339, CK5751, CV10319, CV4004, CV492, CV8156, CV8222, CV8312, E2164, E83CC, ECC803, ECC803S, ECC83, ECC863, M8137, QB339 Terms of AuctionWe do not low declare customs amount and we insure for full value.International Buyers - Please note: Import duties, taxes, and charges are not included in the item price or shipping cost. These charges are the buyer's responsibility. Please check with your country's customs office to determine what these additional costs will be prior to bidding or buying.International Shipping - items may be subject to -  Customs processing depending on the item's declared value.- Sellers set the item's declared value and must comply with customs declaration laws.- import duties and taxes which buyers must pay.BID 1 FOR THE PAIR!Per eBay's terms of service which every eBay account holder must agree to as part of being an eBay member, a bid is a legally binding contract. Please read the Terms & Conditions carefully before bidding. By bidding on this auction, you understand and agree to eBay's terms of service as well as all terms and conditions mentioned here.Buyer pays all shipping, Item must be in original condition including cosmetic lettering on tubes so handle with white-glove care, un-used with all original boxes, packing material, environmentally safe cornstarch pellets, and shipping box. ALL RETURNS subject to a 10% handling charge. Absolutely NO RETURNS on special orders or best-offer deals. All exchanges must be pre-paid and returned in original packing, complete with no sign of wear or abuse, exactly the same condition as it was when you received it. In the event that the product is not in the same condition, and does not test the same as you received it, you will be subject to a refusal and return, a determined restocking fee, repair charge, or disqualification. RETURN AUTHORIZATION (RA) number and instructions is required before sending any items. Shipping and handling charges are non-refundable.We do not guarantee that your tester, or your tester's measurements will be the same as the Amplitrex AT-1000. Older testers, different testers, or the same tester may report different test measurements, and may not measure the same tube meaningfully (due to current dependency), accurately (due to calibration difficulties) or consistently (due to internal circuit drift) There is no warranty or returns based on what any other tube tester reports.THE COST OF ALL USA SHIPPING INCLUDES INSURANCE, TRACKING NUMBER AND DELIVERY CONFIRMATIONNo zero (0) status bidders without permission, or we reserve the right to cancel your bid. Buyer is responsible for all import duties at price paid for item(s). Please SEE my other ebay Auctions :  Visit this seller's eBay Store!  TubeMuseum   View seller's other items Perfect!!! Wonderful!!! Awesome!!! Definitely the best!!! ***** five stars *****hardos174 ( 235)  Exemplary Testing 1962 RCA 5751 12AX7 MUSEUM CERTIFIED AMPLITREX TUBE 100/100 (#291003724204)Perfect!!! Wonderful!!! Awesome!!! Definitely the best!!! ***** five stars *****hardos174 ( 235)  RCA 5751 12AX7 ECC83 MUSEUM CERTIFIED AMPLITREX TESTED TUBE 1962 USA 130%/120% ! (#291042875850) A+ SellerBuyer: Member id captainbraindamage ( Feedback Score Of 102)  NOS 1960 TUNG-SOL 5751 CV4017 12AX7 GRY PAIR 2Mica O (#230481531967) Awesome seller, asset to ebay, great communication, quick delivery, thank you Buyer: ramb68(26) These guys go out of their way to make every deal smooth, perfect! Thx Mark!! Buyer: repeat-performance ( 75) FeedbackFromLefttube perfect, thank you.Buyer: gheorghe1051 ( 27)   Exemplary Testing JAN Military RCA 5751 BLACK-PLATE 12AX7 AMPLITREX TESTED TUBE (#291262098065)