I have a fender blues deluxe, and I want to replace the tubes because I get a lot popping and crackling(the low end is also muddy when cranked). My amp has 3 12ax7 Groovetubes preamps and 2 6L6B power amp Groovetubes. I am looking for advice on good tubes that will add a little clean headroom to my sound. I have never changed tubes before so I am not sure about matching/biasing. Please help!

1989 Fender MIA Strat Ultra
2006 Fender Standard Strat
1985 MIJ Fender Telecaster
Martin SPD-16R

Fender Blues Deluxe

Fulltone OCD :
EH Memory Man
Xotic RC Booster
Boss RC-20XL(looper)
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12at7's will give you more headroom than the 12ax7's in the preamp. I'm not sure of whether you need to swap all of them out or just a specific single or two or them as I am not familiar with your amps circuit. Others will know tho.
I dunno for preamp, but in the power amp of my HRD I had JJs and they sounded nice. If you want more clean headroom I you should just bias it colder. http://studentweb.eku.edu/justin_holton/
That's a great site and will show you how to properly change the tubes and bias the amp. Taking your amp to a tech is huge waste of money if you only want him to change the tubes.

What gregs said will work to reduce gain, especially on the drive channel, but won't work very well to increase your clean headroom.
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