7189 id help and grid leakage question

[nyindallas]

Just received the Scott 222C with the new rectifier that did not have the resister updated, I am waiting for a resister before I test.

The 7189's are supposed to be new. They pass the emission test and life test but all fail the grid leakage test. I also can not identify the make. See photos.

1.Should I be concerned about the grid leakage results?
2.Anyone know what brand these are? The markings are DTK 2, 0683
3.Can I use EL84's for the 7189 w/o any upgrades? I have JJ EL84's in another amp and they work great.

Thanks

[analog addict]

Russian maybe?....:scratch2:

[Ty_Bower]

Those tubes are Russian, made in one of the Reflektor plants. They're good tubes. Most Americans would call them 6p14p-ev. I have a couple sets and I like them a lot. I'd guess your grid leak results are a fluke. It seems odd that all four would fail.

The 7189 has higher voltage and dissipation ratings than a regular EL84. Whether an EL84 would survive depends on the amplifier circuit. I know the 6p14p-ev will take a lot of punishment and just shrug it off. Mine run with 395 volts, cathode to plate. I run them about 32 mA each. They've never arced or red-plated on me.

http://i69.photobucket.com/albums/i43/Ty_Bower/Tubes/th_6p14p-EB-2.jpg (http://i69.photobucket.com/albums/i43/Ty_Bower/Tubes/6p14p-EB-2.jpg) http://i69.photobucket.com/albums/i43/Ty_Bower/DIY%20ST-35/th_P1080747.jpg (http://i69.photobucket.com/albums/i43/Ty_Bower/DIY%20ST-35/P1080747.jpg)

[nyindallas]

Thanks for the reply. Odd thing is my tube tester never shows grid leakage on other tubes I have tested both new and old. Once I get the right resister in this scott 222c I will try them out.

Those tubes are Russian, made in one of the Reflektor plants. They're good tubes. Most Americans would call them 6p14p-ev. I have a couple sets and I like them a lot. I'd guess your grid leak results are a fluke. It seems odd that all four would fail.

The 7189 has higher voltage and dissipation ratings than a regular EL84. Whether an EL84 would survive depends on the amplifier circuit. I know the 6p14p-ev will take a lot of punishment and just shrug it off. Mine run with 395 volts, cathode to plate. I run them about 32 mA each. They've never arced or red-plated on me.

http://i69.photobucket.com/albums/i43/Ty_Bower/Tubes/th_6p14p-EB-2.jpg (http://i69.photobucket.com/albums/i43/Ty_Bower/Tubes/6p14p-EB-2.jpg) http://i69.photobucket.com/albums/i43/Ty_Bower/DIY%20ST-35/th_P1080747.jpg (http://i69.photobucket.com/albums/i43/Ty_Bower/DIY%20ST-35/P1080747.jpg)