Jump to content

How much to convert a JCM900 head from 6L6's to EL34's?


cvogue

Recommended Posts

  • Members

 

Originally posted by slash81291

idk if youw ant one with el34's just look around.. it should be easy to find one with el34's for around 5-600$

 

 

Actually they're more rare than you might think... I've been looking a bit.

Link to comment
Share on other sites

  • Members

 

Originally posted by cvogue



Isn't there some rewiring that needs to be done? I think it's more than a tube swap and rebias...

 

 

I don't believe so...my 4100 came with EL34s. I think the amps just shipped with 5881s because there was an EL34 shortage at the time or something.

Link to comment
Share on other sites

  • Members

Originally posted by veil

The cost of a quartet of tubes and a rebias?
:confused:

 

Nope.

 

You must change all the screen grid resistors to 1k, 5 watt and connect pins 1 and 8 on all the power tubes. Then you must rebias and this might not just be turning a trim pot, but also swapping a resistor. My guess would be $50 to $60 labor and then somelike like $45 for the tubes.

 

The $50 is pretty much just a bench fee.

Link to comment
Share on other sites

  • Members

 

Originally posted by Chris Nuccio



Nope.


You must change all the screen grid resistors to 1k, 5 watt and connect pins 1 and 8 on all the power tubes. Then you must rebias and this might not just be turning a trim pot, but also swapping a resistor. My guess would be $50 to $60 labor and then somelike like $45 for the tubes.


The $50 is pretty much just a bench fee.

 

 

Once you've connected the 5 and 8 pin contacts on the sockets , you can still switch back to 6L6s, with a rebias, because that change doesn't effect them at all. Also, the OT may be optimized for 6L6s and may or may not be as good for L34s.......I'm not a Marshall tech, so don't take this as fact about the OT.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...