Matched pair of very rare vintage Siemens power triodes type Eb - an equivalent for the triodes KL 72406 (AD1 with 4 - PIN Europa base) - strongly than AD1 / 72406 with 4V/ 1,5 A heating voltage, 250 V anode voltage, -45 V bias, power 30 Watt (AD1 has 20 Watt only) - in SE power stage possible output power to 8 Watt (the AD1 in SE power stage could deliver to 5 Watt only). These tubes were very fewer used and are in a perfect working condition! I tested these tubes in really condition with a professional tube tester typeL1-3 (very precise tube tester with stabilized DC voltages).The test was made exactly according the data sheet conditions for the tubes AD1/Ed/Eb/EbIII/72406 - with an anode voltage +250 V, grid voltage - 45 Vheating voltage 4 V.Find below the test results of anode current, and transconductance (dynamic slope): 1. Anode current: 130 mA,Transconductance (dynamic slope): 6,0 mA/V 2. Anode current: 130 mA, Transconductance (dynamic slope): 6,0 mA/V I have in my stock still a secondary matched pair pair of identical tubes withan anode current 110 mA, and with a dynamic slope 5,5 mA/VIf you are interested then please write me These tubes have perfect vacuum - no gas! The grid back current is lower than 0,2 µA They are perfect applicable for Klangfilm power amplifiers type KL 32650, KL 32611,and for all other power amplifier with triode power stages. Shipping world wide by courier service DHL Express or UPS - takes 3-4 days only and costs - about 78 EUR (depending of the destination) Possible is also a world wide shipping by German Post, full insured, takes 3-5 weeks andcosts 50 EUR Do not hesitate to send questions to my post box: