The Tube Store tube ratings

[btown]

Hi all,

I have a mark iv, which I got retubed with 6l6 SEDs when I first got it. I bought the tubes from the Tube Store. They sent me tubes rated at "22". It sounded fantastic.

I recently bought a pair of EL34s from them, again SEDs. They sent me a pair rated at "31". Since then, I've had problems with the amp..it seems like the power is going in and out. LEDs get dim, then comes back, and the sound level fluctuates. Is this a tube problem, or does my amp need some kind of checkup?

Thanks for such an informative resource!

 

[Boogiebabies]

The Tube Store states that the number for the perfect pair is the tubes natural plate current. It seems that you 22 may have been fine at -51 volts, but what you really need to know is how much the EL-34's are drawing with -39 volts. If the Tube Stores 31 is too hot at -39 volts, the tube may be drawing so much bias that it is putting a parasitic draw on the low voltage supply. Basically, if your tube is running at 95% at idle it is running wat too hot.

If you have gremlins in your LED's, it may be time for a check up.




Good Luck.