Very rare SYLVANIA 6L6GC 6L6-GC 6l6 gc matched pair DOUBLE RING GETTER big glass model ! Very strong

Here for sale a superb and perfectly matched pair of Sylvania 6L6GC fully tested.
This is a very rare and sought after double ring getter big bottle model. They're getting more and more rare especially in such a nice condition .

Test results       tube 1 :     104 %         tube2 :  106 %

Perfect matching within 2% on my Jackson 648S

They have same code from same batch and were relabeled for Peavey and sold and labeled as "super premium selected"

Superb sounding and very reliable, robust tubes.

These Sylvania sound superb in Hifi or in any guitar amp. Clear, large, fat and super detailed sound, large frequency range, very reactive.

They obviously show little sign of use. See the little marks on the base on the photos. This is no crack or any damage it's just some very superficial scratch from the " tube retainer" found in some amps were tubes are upside down.

Even if little use they are in top condition, full specs and with outstanding superb, thick, large shiny, mirror like getter flash.
Super strong, no leak, and passed all tests with great success.

Hear and feel the difference of true vintage tubes.

I COMBINE SHIPPING ,

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

These tubes has been tested with 2 tubes testers

one 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 regularly tested for calibration.

 Photos are part of the description you get what you see.