NOS matched pair of MULLARD Holland I65 12AX7 ecc83 super STRONG ! Orange Hiwatt Marshall, preamp.

Here for sale a very nice matched pair of Mullard 12AX7 ecc83, super strong
Both made in Holland at the the great Mullard- Philips -Amperex factory of Heerlen , both the same year! First one made the fourth week of april in 1963 and the second the fourth week of june in 1963 too.
This pair is absolutly NOS new unused .
Perfect condition and splendid getter flash on both tubes.
Hard to find such a perfect NOS super strong and so nicely matched in every aspect !

Tests results

• Code I65   Δ3F4      113 %   115 %
  

• Code I65   Δ3D4      114%   119 %
  

 Perfectly mached and balanced within 6 % so ideal in any stereo device..

Very unique and detailed sound, astonishing and fantastic in high gain stage to get a more define and less muddy sound. Many vintage Marshall player love them even more than the more renowed and so great british Mullard Blackurn.
Crystal clear clean with warmth.
Very sought after by audiophile and pro recording studio for their imcomparable 3D midrange ( Wich is subtlely more pronounced than Blackburn ones) this makes it an outstanding tube for guitar and vocal . It Has good bass and sweet pleasant highs too.
Those I65 have little ring getter.


Let your Marshall, Orange, Hiwatt or any nice amp get its full original tone . Hear and feel the difference.

I COMBINE SHIPPING ,

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

Shipping cost 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.