The New Old Stock G.E.C. test results prove this is an excellent tube
First, you need to know what the Amplitrex is. The Amplitrex AT-1000 is the state of the art computerized tube tester and one of the only tube testers produced that is able to work independently and has custom interfaced software for PC operation. The Amplitrex AT-1000 is a current production tube tester and unlike tube testers built 35 to 55 years ago, the Amplitrex offers laboratory grade testing under microprocessor control and makes it possible to check a tube according to the original manufactures design specifications. Even more valuable is the ability to duplicate not just our guitar amplifiers circuit parameters but any guitar amp parameters. With the Amplitrex AT-1000, we can test our tubes under the same conditions for which they are going to be used within our Mojave tube amps. Real life guitar amp circuit parameters work with more then 150 volts which is what most old testers use. The Amplitrex can put up to 500 volts on the plate @ 160ma of plate current. a Marshall super lead runs the power tubes anywhere from 460 to 500 volts on the plate. With the Amplitrex, we can duplicate these parameters. This means the tube will run on the tester as it would in the amplifier.
The ability to heat the tube up at the same temperature means any mechanical defect that would be subject to change because of temperature will be weeded out on the spot. Many other important variables are more likely to be brought to bare under real operating conditions. This important tube performance data cannot be duplicated with older “Proportional” type tube testers that use lower test voltage because the typical voltage applied (around 150 volts) simply does not stress the tube or create the heat and current flow that will be seen inside the guitar amplifier on stage in front of hundreds if not thousands of people where a failure is out of the question. Even if your just at home, your not going to have to worry that you paid for tubes which might not be good.
Because of this difference, you could feasibly buy a set of expensive new old stock power output and preamp tubes which were tested on a 35 year old tester and not get the facts. You wind up wasting money because you get your new tubes and they crap out after they are put in a guitar amp because they run hotter & harder then the tester they were checked out on. With the Amplitrex AT-1000, your tubes are tested exactly the same as the intended circuit they are to be used in.
In short, by having your tubes tested with the Amplitrex AT-1000, you see the following benefits:
- Your tubes are sure to be dependable.
- Audio tubes are certain to sound good.
- Tubes graded on the Amplitrex are known good and are going to last longer.
- N.O.S Pre amp and Power tubes are worth what you paid for them
- An audio noise test is performed. Only low noise tubes are passed.
- The Amplitrex assures your tubes are not contaminated internally
- Peace of mind that your tubes are certain to work without question.
- You can get your tubes exactly matched so you keep spares that do not need to be re biased by a technician.
- Your tubes are going to make plenty of clean power
- your tubes will not have weird sounds
- Higher gain tubes help produce better harmonics and clipping for overdrive.
A New Old Stock G.E.C. KT-66 test results are displayed.
The Amplitrex AT-1000 is without question the best tube testing product available. Mojave Ampworks builds top quality amp and we spare no expense even down to the quality of our tubes and especially our tube testing which is fundamentally critical for your product performance and reliability.
The Amplitrex provides a dated and time stamped data sheet for all tested tubes. We are happy to provide you your dated time stamped test results upon request.
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Hey. Did you ever try to compare the Amplitrex against any other top-line tester? After getting a handful of my 12ax7 tubes checked on an Amplitrex and seeing many examples of Ebay sellers who claim they own Amplitrex’s themselves, the tube Gm values I see reported from the digital instrument are ALWAYS, in every single case, considerably higher. I’d say, by a 20% or so. Your experience?
The Amplitrex puts a 1KHz signal so it applies audio to the device and that is where the GM is derived.That is a more accurate way then simply shifting a DC voltage on a grid. That is why the true readings are somewhat disappointing when you buy new tubes and all is well with the average test.