1 - Replace the stock 6V6's with 6L6GC's or 6L6WGB's and rebias.
2 - Replace the rectifier tube with a solid state rectifier plug in.
3 - Replace the filter caps (if they have not been done for a long time, not applicable to the reissue Deluxe Reverb).
4 - Replace the speaker.

Let's go through this step by step.

1. The 6L6's are going to give more bass than the 6V6's. 6V6's are just weak in that area. The 6L6's are a direct plug in replacement for the 6V6's IN THIS CASE ONLY, but do require rebiasing. 6V6's should not be put into a 6L6 amp! Go here to read more about tubes.

2. The solid state rectifier will boost voltages in the amp which will increase power. This is even more pronounced when you go from a 5U4 amp to the solid state. Be warned! Sometimes adding the solid state rectifier will cause problems. These problems are fixable, but you probably should use the amp for a few hours at least before you bring it to a gig with this mod. This will help ensure that the amp is going to handle the increased voltage. DO NOT install the solid state rectifier in a stock amp (with 6V6's).

3. Old filter caps may not like the new higher voltage you put on them. I would not do this for anyone unless they changed the caps as well. You could do the mod without changing the caps, but there's no guarantees that you are not going to cause them to fail! Don't be a fool and do this mod with the original caps. Just change them. If you have a reissue Deluxe Reverb, then it does have higher voltage capacity in the filter supply. The filter supply on these is more like a bigger amp.

4. Stock Deluxe Reverb speakers suck in almost all cases. The stock speaker will probably not be able to handle the power increase, so get a new one. Weber VST has some excellent choices!

I like the tone this mod gives. It makes the Deluxe Reverb respond more like the Vibrolux Reverb. The amp will have more clean headroom and bass response. It really fattens up the tone. If you play clean mostly, it's almost assured that you will love this! You are not going to get that ratty crunch that the 6V6's get though! I've done this to a few Deluxe Reverbs, and the owners all liked the results. The best thing about this "mod" is it isn't irreversible! Going back to original setup is a snap! BUT, if you don't want extra volume and a cleaner overall sound, don't do it!

This mod IS NOT applicable to a Princeton Reverb due to it's overstressed power transformer. They absolutely will not take the extra abuse the 6L6GC's give it.