Description: 5 Telefunken 12AX7 tubes Made in West Germany and of vintage manufacture. Good testing & great sounding tubes! Free from gas, leakage or shorts. Voiced in preamp circuit. Quiet. No noise or microphonics. Clean pins/glass. Excellent gettering. Top, halo-getters. All have the diamond mark <> in the bottom glass. Two rib-plate marked Telefunken. Three smooth-plate marked Dynaco and GAP/R. Tested on a calibrated TV-7D and at real operating voltages on an Amplitrex AT1000 in fixed bias mode. All tubes ran-in for 15 min each before tests to ensure stability. TV-7D test results: Tube 1- 54/48 Tube 2- 48/48 Tube 3- 52/46 Tube 4- 45/46 Tube 5- 42/42 Minimum good is: 32/32. AT1000 test results: Tube 1- Gm: 1.69/1.50 mA/V. Ip: 0.9/0.8 mA. Tube 2- Gm: 1.50/1.60 mA/V. Ip: 0.8/1.0 mA. Tube 3- Gm: 1.80/1.40 mA/V. Ip: 1.3/0.8 mA. Tube 4- Gm: 1.40/1.50 mA/V. Ip: 0.8/0.9 mA. Tube 5- Gm: 1.30/1.37 mA/V. Ip: 0.6/0.7 mA. Minimum good the 12AX7, per section: 1040 µmohs, 0.75 mA. Nominal new 12AX7, per section- 1600 µmohs, 1.2 mA. Tested parameters- 250v plate, -2.0v grid bias. In conclusion- These test as good & quiet tubes. An excellent addition to anyone's collection. Money back guarantee you will not be disappointed. >>>>>>>>Also listed on US Audiomart for $225<<<<<<<< All items are 100% guaranteed to arrive as represented for 30 days upon arrival. I offer a full refund if you are not satisfied. We've been selling vintage electronics since 1999 with perfect ebay feedback and many happy, satisfied customers. All items professionally packed to arrive safely with no extra handling costs. Our mission is to offer quality-tested tubes to make you happy with your purchase. Terms & Conditions: Payment must be received within 3 days of sale date. Items described to the best of my ability. Shipped by U.S. Priority Mail. If you have questions, please contact us BEFORE purchasing. Thank you!
Price: 265 USD
Location: Orinda, California
End Time: 2024-11-05T00:20:43.000Z
Shipping Cost: 0 USD
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Item Specifics
All returns accepted: ReturnsNotAccepted
Brand: TELEFUNKEN
Type: Preamp Tubes
Model: 12AX7
MPN: ECC83
Country/Region of Manufacture: Germany
