RARE: GE 6350 NIB/NOS PREMIUM GRADE 12AU7 Platinum Matched on AT1000

RARE: GE 6350 (12AU7) Tubes (NEW in BOX) Premium Grade 12AU7 – TESTS NOS Long Black Plates – “Ring” Getter – Matching Date Codes Triple Platinum Matched on AT1000 The 6350 tube was mainly manufactured for IBM and other computers in the late 1950s to mid 1960s. Sylvania and GE black plates are considered the best. The only difference is the pins that correspond to the grid and plate of each triode are reversed from the 12AU7 connections, so you will either need to rewire your sockets to take this tube, use an adapter or consult with the manufacturer of your unit to see if this tube can be used as a sub for the 12AU7 . The gain factor of 18 is very close to the 12AU7. These were made to tight specs and carefully quality checked, since replacement in a computer of the day was difficult and costly and the tubes were expected to operate 24-7. These make a VERY impressive upgrade to the standard 12AU7… Triple Platinum Matched on Amplitrex AT1000 Amplitrex AT1000 Test Results 95%+ GM = Within NOS Specs 90%+ EM = Within NOS Specs (GM) Mutual Conductance 4600 = SPEC (EM) Emission 5.0 gV = SPEC Noise Test (Mu) Tube Gain TUBE #1 4630/4630 (100.7/100.7%) 5.2/5.1 (104.0 /102.0%) 5/5 16.2 16.7 TUBE #2 4700 /4700 (102.2/102.2%) 5.3 /5.2 (106.0/104.0%) 5/5 16.8 16.8 TUBE #3 N/A N/A N/A TUBE #4 N/A N/A N/A PERFECT = 0.0% (5% or less = Outstanding) Balance (Balance Goal = Mhos > 5% / Gv > 10%) Tube 1: A to B = Mhos – 0.0% Gv – 2.0% Tube 2: A to B = Mhos – 0.0% Gv – 2.0% Match (Tube 1 to Tube 2) (Match Goal = Mhos > 5% / Gv > 10%) Tube 1A to 2A = Mhos – 1.5% Gv – 2.0% Tube 1B to 2B = Mhos – 1.5% Gv – 2.0% Noise Test Scale: 5 = Ultra Low; 4 = Very Very Low; 3 Very Low Tube Gain Scale : 17 Mu (+ or -) 3 Mu = Within Factory Specs BULLz TUBEz About BULLzTUBEz: I’ve been an Audiophile for over 50 years, 2 time National Champion in Car Audio and owned a chain of Car Stereo Stores… I have a massive collection of vacuum tubes specializing in mostly esoteric tubes but we have just about any tube you need. Just check the store for the listed inventory. If you have a request just send a message to NOVA.76 through the eBay messaging system… About our TUBEz: All tubes are tested with the Audiophile in mind for SHORTS, GAS, MUTUAL CONDUCTANCE and NOISE (large tube lots are not tested for noise). All my tubes are tested thoroughly on an Amplitrex AT1000… My backup tube testers are an AVO MKiv and another Amplitrex AT1000… I WILL NOT GUARANTEE THAT OUR READINGS WILL MATCH YOUR READINGS… I stand behind everything we sell… My goal is to “Create a Positive Experience” for my customers… Warranties: Used or vintage items are sold as is with no warranty beyond the description and photographs provided on the listing. Returns will NOT be accepted for reasons such as: ordered the wrong item, changed mind, not what I thought it was, wrong color ordered, wrong item ordered or tube readings don’t match my tester. Any exceptions are on a case by case basis… Shipping: Domestic Shipping to the continental United States will be by the US Postal Service (USPS) including free tracking. Some items listed will ship free and will be clearly listed as “free Shipping”. Items not listed as free shipping will be for the cost of packaging plus shipping only, no extra charge will be added to the USPS fee. INTERNATIONAL BUYERS PLEASE CHECK THE SHIPPING CHARGES PRIOR TO BIDDING International Shipping will be offered for select items and will be clearly identified in the listings Shipping & Payment tab. Shipping will be by the ” eBay International Standard Shipping ” and be made available as a shipping option at check-out. Shipping costs to international locations will be paid by the buyer. The shipping and handling cost will be clearly identified at check-out. THERE ARE NO RETURNS ON INTERNATIONAL SHIPPING , apart from the exceptions as dictated by eBay… Please note the following: Import duties, taxes and charges are not included in the item price or shipping charges. These charges are solely the buyer’s responsibility. Please check with your country’s customs office to determine what these additional costs will be prior to bidding/buying. These charges are normally collected by the delivering freight (shipping) company or when you pick the item up – do not confuse them for additional shipping charges. We do not mark merchandise values below value or mark items as ‘gifts’ – US and International government regulations prohibit such behavior.