Doug's tubes - Plate Current for Simul Class

[Boogiebabies]

I would call Ned. He's not a blackberry kind of guy. A bit old school.
The outer sockets would bias a bit hotter, probably 33ma. I did some
tests with them for Platypus a while back, I may have written them down.

 

[floridamike]

Hey BB, speaking of tubes, can you run just two tubes in the class A spots without the others or do you have to keep all four installed even though you're in Class A and only using the two?

 

[Boogiebabies]

In class A, the two inner tubes are virtually off. They see no plate current when the ground is lifted. It does no wear on them. The only thing running are the heaters, which usually last a lifetime. For the sake of avoiding a potentially fatal accident to the OT, I always run tubes in the inner sockets. With enough bad luck, any of us could be the guy who's Simul/Class A switch shorts and blows the OT.

 

[seajay]

Do you mind linking to the thread containing rabies's post that you are referring to?

http://forum.grailtone.com/viewtopic.php?t=23805&highlight=doug
I'm just concerned that he doesn't have any Marks to test with, especially those with Simuls.

This is what I got from his email as a response to my question whether a quad SED 6L6GC with similar current draw (I didn't know better) would work on my IV, which only adds to the doubt.

Hello, They should work fine in the MKIV, just not in Simulclass. Isnt there a straight 6L6 setting?

The general sentiment is positive towards him though, so maybe I'll give him a shot anyway.

~trem

Thanks for the link sir!

It sounds like Doug is getting confused with the Rectos that have a 6L6/EL34 switch. He may not realize that the outer tube sockets in the Mark IV are "plug n' play" between the 2 tube types.

I would think that as long as he gives you tubes within "Mesa spec," they will work fine in all tube positions. Mesa doesn't sell tubes that are specified for Simul-class amps. As long as Doug sells you tubes that are the same rating as Mesa tubes, you should be fine.

 

[trem]

I would think that as long as he gives you tubes within "Mesa spec," they will work fine in all tube positions. Mesa doesn't sell tubes that are specified for Simul-class amps. As long as Doug sells you tubes that are the same rating as Mesa tubes, you should be fine.

That's what I thought until I saw this thread:
http://forum.grailtone.com/viewtopic.php?t=16487&highlight=weber
Look for Joey's posts.

 

[JOEY B.]

I would think that as long as he gives you tubes within "Mesa spec," they will work fine in all tube positions. Mesa doesn't sell tubes that are specified for Simul-class amps. As long as Doug sells you tubes that are the same rating as Mesa tubes, you should be fine.

That's what I thought until I saw this thread:
http://forum.grailtone.com/viewtopic.php?t=16487&highlight=weber
Look for Joey's posts.

Let's make sure that something is understood. The IIC+ or any Coliseum Mark has a high enough plate voltage to be very cautious about the tube selections or positions. The MkIV will be fragile to 6L6's in the outer sockets with non-MESA branded tubes (outside the MESA range). EL-34's will be hard pressed to run hot in the outer sockets, from what I've seen. 8)

 

[trem]

Let's make sure that something is understood. The IIC+ or any Coliseum Mark has a high enough plate voltage to be very cautious about the tube selections or positions. The MkIV will be fragile to 6L6's in the outer sockets with non-MESA branded tubes (outside the MESA range). EL-34's will be hard pressed to run hot in the outer sockets, from what I've seen. 8)

Ah, thanks for the clarification. So are you saying, unlike the IIC+ with its higher plate voltage, I can use STR440s that have rating other than 'red' on the outer sockets?

 

[trem]

I would call Ned. He's not a blackberry kind of guy. A bit old school.
The outer sockets would bias a bit hotter, probably 33ma. I did some
tests with them for Platypus a while back, I may have written them down.

Thanks BB! So #32 6L6s too for the outer sockets?