Hi all so I have a Mesa Boogie Dual Rectifier that I got used off of craigslist and I haven't yet swapped out the tubes. I think that they're between 2-3 years old (they are groove tubes if it matters). I'm going to be recording a new record soon and I'm wondering if it would be better to do a full retube or spend my money on a renting a high quality preamp such as an avalon 737. I am currently just plugging a 57 into a firepod right now. I have heard mixed opinions on how better your sound. Some say the result is just as drastic as changing old guitar strings and if that is the case I will probably go for the retube but others say it makes almost no audible difference. Please enlighten me. P.S. Hope this is in the right section.