Superb ultra rare SIEMENS 12AU7 ecc82 SILVER PLATE matched pair very strong, fully tested Superb sounding tubes !

Here for sale is a super rare and awesome Siemens silver plate 12AU7 ecc82 matched pair.

Early GF0 model , silver ribbed plate, copper rods. Both made in 1962 one in February the second in march. So super close production .

Tests results   tube 1 : 101 % 105 %

Tests results   tube 2 : 104 % 104%

Code Gf0 #2C and #2B

Super strong nicely balanced and matched ( within 4 %) so great for stereo use.

When giving them my usual auditioning test for sound , noise and microphony prior to listing, I really appreciated the superb sound qualities of these tubes . Full, very open and detailed, highly musical and pleasant to the hear. A lot of clarity and a very large dynamic range, they render perfectly with transparency light whisper as well as loud and heavy instruments and sounds. Really great.

They promise long sweet music sessions.

No surprise they are highly sought after by most regarding audiophiles and connoisseurs.

Microphony is ok, even if not totally my "V1 A+++ grade" in term of microphony, but they tested perfectly fine in first stage in preamp concerning microphony and should be absolutely perfect in Hifi or driver use.

They are both super quiet.

Great sounding tubes !

Perfect top condition.

I COMBINE SHIPPING ,

 SO PLEASE HAVE A LOOK AT MY OTHER ITEMS AND SAVE .

Shipping price includes tracking and insurance

This tube has been tested for
Heater filament test: Short circuit
Heater filament test: Open circuit
Heater filament test: Tolerance check
Heater cathode insulation: Leakage
Heater cathode insulation: Short Circuit
Tests for heater current abnormalities
Amplification factor
Voltage gain
Power gain
Screen grid test
Mutual conductance test
Dual test for double triodes
Emission
Inter electrode leakage
Inter electrode short circuit
Flash-over (arc detection, high voltage breakdown)
Gas ionisation test with a first tester
and then with a second tester ( Jackson 648S ) for
Filament Circuit Shorts Plate Life test...

The Jackson 648. It is definitely one of my favorite tube testers. While it does not employ a mutual conductance test circuit, it does use an advanced emission circuit that applies separate element voltages to each tube element, and separate load circuits are also used. “These voltages and loads have been carefully selected for each tube to meet most ideally the normal operating condition of the tube.” (Source: 1950 Jackson catalog.)

In my experience, the Jackson circuitry is very effective, and often will surprise you with accuracy that approaches Hickok’s coveted “mutual conductance” test method. ( Source tubesound web site.)

I do my best to test and describe the tubes the best I can. Note that test results may vary from one tester to an other so this must be taken as an indication, although my jackson is regulary tested for calibration.  Photos are part of the description you get what you see.