Anyone have experience using new production KT66 power tubes

[Mike_J]

I have been researching new production KT66 power tubes.  The Tungsol and Chinese version both say the will take up to 499 volts B+ while the JJ version will take up to 550 volts B+.  I expect that some of these voltages are with the tube biased fairly cold.  My PT will generate B+ of approximately 489 volts so I don't want to be blowing tubes every other day.

The logical decision would be choose the JJs except they rate poorly in tone by some.

Does anyone have experience using current production KT66 tubes at a B+ approaching 490 volts?

Thanks
Mike

[Mike_J]

Doing more research.  The Genelex KT66 datasheet has max plate voltage of 500 volts and screen voltage of 400 volts.  There is no way those voltages weren't exceeded in the JTM45/100 amps.

I have read that the Gold Lions exceed 500 volts in a JTM45 without problems.  That means the screen voltage will also exceed 500 volts because the 100 ohm resistance of the choke is not going to knock the B+ down by more the a few volts.  The Gold Lions seem to be liked from a tonal point of view.

Thanks
Mike

[Ed_Chambley]

I use the Gold Lions.  They sound better to me in a guitar amp than the original GEC, plus I do not have but a treasured few of those and I a quite sure I will not be buying any in the future.

I got them in a JTM45, an original one.  I have played that amp outside in the Georgia summer at full tilt.  No problems so far.  Guessing, I put them in a little over 2 years ago.  The amp is played hard on the average of 1 time every 2 weeks.

[Mike_J]

I use the Gold Lions.  They sound better to me in a guitar amp than the original GEC, plus I do not have but a treasured few of those and I a quite sure I will not be buying any in the future.

I got them in a JTM45, an original one.  I have played that amp outside in the Georgia summer at full tilt.  No problems so far.  Guessing, I put them in a little over 2 years ago.  The amp is played hard on the average of 1 time every 2 weeks.

Thanks Ed

I have been reading other posts on the net regarding the use of the Gold Lion KT66 in a JTM45 or 45/100 and all reported excellent results as you have.  That is the direction I will go too.  I try to use new production tubes for any amp that I build with the exception of some RCA 7025s in certain positions.  I think it is insane to spend $600 for two tubes. 

When I started making amps I picked up NOS Tungsol 5881s and RCA blackplate 6L6GCs and a lot of 12a_7 tubes.  They weren't very expensive then.  Thought I needed the NOS tubes to make the best sounding amp.  Given the price of NOS tubes it makes no sense to use them.  I too have a stash of the old tubes but won't use them because they are just worth too much. 

Unfortunately, the Winged C 6L6GC is going away.  I made my 124 with them less than two years ago and paid $108 for a matched quad.  I read today that they are asking that for a single tube now if you can even find them.  If I had know they were going to be discontinued I wouldn't have used them although they are a great sounding tube.

Thanks
Mike