Early Telefunken 12AU7 Tubes Smooth Plate 3 Mica Amplitrex Strong Balanced Quiet, US $186 – Picture 0

Early Telefunken 12AU7 Tubes Smooth Plate 3 Mica Amplitrex Strong Balanced Quiet, US $186 – Picture 1

Early Telefunken 12au7 Tubes Smooth Plate 3 Mica Amplitrex Strong Balanced Quiet

US $186

Coweta, Oklahoma, United States
Nov 15th

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Early Telefunken 12AU7 Tubes Smooth Plate 3 Mica These are an early version 12AU7 by Telefunken. Smooth plates, large logo on glass, diamond bottom and 3 mica support (see picture 3). Tested on an Amplitrex AT1000 digital tube tester with 250 volts on the plates and -8.5 volts on the grids at fixed bias.* Typical new will read 2,200 Gm @ 10.5ma plate current draw. Then it is tested in a custom built amplifier where each side can be listened to individually for tube noise and microphonics. These tubes read: Tube 1: 2,500 @ 10.8 and 2300 @ 9.6ma plate current draw Tube 2: 2,300 @ 10.2 and 2,100 @ 9ma plate current draw These tubes are very strong, balanced and dead quiet. You will love the sound. * With fixed bias, test voltages are set on the tester according to the tube manual specifications. Readings of the tube can then be compared to the tube manual to see how well the tube functions. With auto bias, the grid bias is automatically adjusted by the tester until the tube reaches optimal performance. This grid voltage may be way out of the range of your equipment and therefore the tube may not operate as intended. Pictures tell the rest of the story and are part of the cosmetic description so please take a close LOOK at them. You will receive the item(s) pictured. Please ask any questions before you bid to avoid any communication problems or disappointments. Why Buy From Elderly Electronics: We know you have thousands of choices when it comes to purchasing vintage electronics on eBay. Our main goal is customer satisfaction and to help you revive that special piece of equipment with quality tubes, parts, and manuals. Our feedback speaks for itself. We are experienced sellers on eBay since 1999. Please check our feedback and eBay rating. Items shipped within 24 hours of sale and usually same day if order received by 3pm CST. We don't mess around. Free USA shipping on all Buy It Now auctions. We use new boxes and bubble wrap for packing. If packing peanuts are required to help protect you purchase, we use anti-static & 100% bio-degradable peanuts made from corn by-products. This leaves no mess in your office and you can just toss them when cleaning up. Hassle FREE 60-day money back guarantee from the time you receive item(s) so you may check them out. Longest return policy on eBay because we have the faith you will love our products. Positive feedback left for you once payment is received as you have done your part. I will strive for positive five-star feedback from you by describing the item accurately, packing item so it will arrive safely and then sending you the tracking information when the item ships all of which we will do. International Bidders: We ship worldwide with free insurance and welcome your business. I'm happy to combine shipping to save you all I can. If you purchase several Buy It Now auctions within 24 hours of each other, I will refund shipping overcharges when items ship. Non-Profit shipping. You pay actual shipping charges only. Tube testers we use include but are not limited to: Triplett 3444 laboratory grade with digital milliamp meter. Rebuilt with precision calibration by GC Industries in October 2015. Used for testing Pre-amp and power tubes. Amplitrex AT-1000 digital tube tester, the world's most accurate vacuum tube tester. TV-7B/U Military tube tester with a digital meter. Rebuilt and calibrated by Dan Nelson June 2015. Used for testing rectifiers and radio tubes. Sencore TC162. Used for finding that troublesome shorted or leaky tube. Tube pre-heater. Custom built and used for warming up and stabilizing pre-amp and power tubes for at least 5 minutes. All testers are regularly checked for calibration to ensure accurate test results. Thank you for visiting our auction