Getting the "red" out of my SP-P....

[neonthecat]

....the "red-plate", that is!

I've mentioned the red-plate display I've been seeing on the Electro-Harmonix EL84's. Very dim glow, true, but still wondering what this means for tube life.

Russ recommended JJ's and Ian did too, along with Russian NOS 6P14P's (I got those from my usual ebay source).

Ordered both brands a couple of weeks ago. They arrived yesterday, and I wasted no time in plugging them in. After a couple of hours playing music with each, I'm happy to say neither the JJ's nor the Russians had any glow on the plates.

Then, what's up with the E-H tubes anyway? The Russian 6P14P's look near identical, except for a slightly different getter configuration. The ebay seller said the tubes came from the "Reflektor" factory. Isn't that the same place that produces tubes for E-H?

[bob91343]

Measure the plate dissipation. It seems you are running on the ragged edge, and a bit more bias may be called for.

[Ty_Bower]

I'm guessing your EH are the ones with the dish (flying saucer?) type getter at the top. Are the old stock Russian ones the kind with the two post ring getter? They're military, and might handle a little more abuse.


http://i69.photobucket.com/albums/i4...6p14p-EB-2.jpg

[neonthecat]

Originally Posted by Ty_Bower

I'm guessing your EH are the ones with the dish (flying saucer?) type getter at the top. Are the old stock Russian ones the kind with the two post ring getter? They're military, and might handle a little more abuse.


http://i69.photobucket.com/albums/i4...6p14p-EB-2.jpg

That's exactly right, Ty.

[Ian444]

Originally Posted by neonthecat

Then, what's up with the E-H tubes anyway? The Russian 6P14P's look near identical, except for a slightly different getter configuration. The ebay seller said the tubes came from the "Reflektor" factory. Isn't that the same place that produces tubes for E-H?

The difference might be the NOS Reflektor tubes were probably made around 25 years ago I like the Reflektor tubes from the eighties, no failures, consistent performance. Some of the current production Russian tubes are good, and some not so good. I often use Jim McShane's tube page, and google forums including guitar forums to help sort out what's hot and what's not.

Edit - Did you notice any difference in sound between EH, JJ and 6P1P-EV?

Ian

[neonthecat]

Originally Posted by Ian444

......snip....

Did you notice any difference in sound between EH, JJ and 6P1P-EV?

Ian

Too early too tell, Ian, as I just plugged the JJ's and the 6P14P's in only long enough to watch for red-plating. The E-H's had about 50 hours when I pulled them and they sounded nasty at first, but now sound pretty decent. I'm not sure I'll detect huge differences in sound between EL84's in this circuit. Now my SSE is another story; it seems very fussy as to tube selection.