Special Power Tube Question

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robnutting

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Hey, if I play exclusively in the 5 watt mode, can I just have one power tube installed? Or will this affect the amp adversly?
Many thanks
rob
 
That would not be a good thing. For technical reasons, the amp needs all four tubes, even in the 10 watt setting. Why would you do this?
 
I would rather use one tube instead of four because it would save on tubes. But if I need to have all four in, then I guess that's just how it is.
 
Your four tubes will last longer if you use all four, the voltage and current passing through them would be spread out
between all four and not just one. If you use just one, the lifetime of that tube may very well be limited to day, hours, even minutes, if you did not endure more damage than just to the tubes. I also doubt the sound would be of any quality.
Just my thoughts.
 
I think you guys are off base. One tube should be fine, as long as you don't switch out of 10 watt mode. If the other tubes are out of the circuit, then they're out. I used to run my MK II C+ with only outer 34's in it and never had a problem. The LSC manual states that you can run 6v6 in the outer only in 50 w mode.
 
First of all,Don't do it!!!!!!Second,even in the lowest power setting 2 tubes are operating (though only one is for audio)......This is covered in the owners manual which I'm sure you've read,right?
 
litespeed said:
First of all,Don't do it!!!!!!Second,even in the lowest power setting 2 tubes are operating (though only one is for audio)......This is covered in the owners manual which I'm sure you've read,right?

YES, you are right. Actually, three tubes are used in the single-ended Class-A mode. Two tubes are running parallel in Class A, and the last one is used to balance the output transformer correctly (as it is not originally made for single-ended Class A). Using only one tube would seriously damage your amp at the least, most likely destroy it requiring replacement of most central parts.

And as mentioned, this is covered in the manual, thus most likely not covered under warranty. Just my 2 cents... :wink:
 
Yes, this will affect the amp adversely.

Some amps are fine with removing a pair of tubes in order to get that 1/2 output thing going, but this is precisely why there's a switch on the front of your Lone Star. It's designed with all the tubes in mind (unlike Class A amps with just one power tube socket). Would you want to risk having that switch flipped by accident, with only 1 or 2 tubes in there? Then it would just be a race to see whether your fuse will blow in time to save your output transformer. Pow! (edit: I don't actually know if it's the output transformer that would blow. But something important would blow unless the fuse does.)

If you're really trying to save on precious tubes' lifespans, you could get a pair of cheaper tubes and run them in the "off" positions (definitely work in pairs, though). That way they're still soaking up whatever the amp needs to send through them, but they aren't really a factor for tone.
 
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