Question on Tube Swapping and Biasing

Great, thanks!

As is usual with Luxman this is all they have to say about it in the manual "When repairs and adjustments are needed, please consult 
with the dealer where you bought the unit." since they'd really rather have you not messing with it.

FYI, bias is a moving target. Knock your brains out trying to get it right on the money then blink. In theory a matched quad is all you all you need to do but the primary caution is not having a single tube or tubes drawing significantly more current than any of the others. Other than that, the bias is likely to be all over the place at anyone given instant and is nothing anyone with a tube amp should ever obsess over.

Your JJs are probably still just fine and unless you have any particular indication that things are not as they should be, you should leave them alone.

Thanks for your suggestions. Obviously there's a variety of opinions on how to approach this! 

From a dealer / manufacturer point of view, they obviously want to err on the side of caution and recommend that you use a professional audio repair shop to carefully check the bias on a regular basis. So I suppose that's one end of the spectrum. 

I was told by the Luxman guy that, since I stupidly removed the original JJ tubes without noting which one went where, if I out them back in I'd have to bias the JJ tubes all over again. The Gold Lion are indeed a matched set. So technically I need to bias the tubes. 

Then again, I've had the amp 5 years without worrying about bias at all. I'm sure it's changed over time. 

Have to say, I'm more confused than before!

Sounds too complicated for me.  Think I'll stay with a SS upgrade.

VTL bias meter

This is a great way to safely check bias