So, I needed to replace a battery compartment in my 1980 Guild B401-A. It's my main player and I do like the sound both passive and active. Still, I'm always one to look for possible improvements. Modernization is welcome and doesn't scare me. While I was asking around about some tips on the compartment, one person suggested that an entirely new modern pre-amp could really kick things up a notch. Firstly, it does not have a standard low-mid-high EQ setup. It has a Mid Shift with a Mid cut/boost. One volume plus the the two mid knobs. I guess there might be some routing involved to accept a new pre-amp. I really don't know the answer or approach to that. The idea generally does not appeal to me in that regard. My main love for this bass is that the neck and body fit me well. I'm only 5'10 180. Pretty medium sized guy, but I prefer large basses and long scales. So what do you all think of the modern pre-amp suggestion? Btw & Fwiw , the original pre-amp is very clean and has a simple elegant look. Of course you only see that while looking 'under the hood'. Just wanted to point out that it's no mess of wires and such. As far as being a lifetime keeper, I'd say yes, but a Guild B402 in the right condition and body wood, could compel me to sell it. I've always wondered if I'd miss the simplicity of the single pickup, but like the possibilities a two PU Guild B400 series would offer.