Kissmybass

Cheers for info guys....

Hi all, I am fairly new to the bass world and have just bought my first amp head (been borrowing kit for a year). It's a Trace Elliot ah350smx gp12 and sounds amazing to my inexperienced ears. The guy I bought it off said he does not think the valve has ever been replaced. I was hoping that changing this would give a bigger/better valve sound, as it only has minimal presence at the moment. I assume a new valve would improve this?. I am not worried about putting the original type in. What I would like to know is has anyone experimented with different types or know what would go really well in this amp. Don't know how to describe the sound I'm after, just that I want the wow factor if that's possible (naive way to describe it I know) Thanks so much for reading......