educate me on vintage MXR envelope filter

[scuzzy]

I was given this pedal by an acquaintance from church that I'm helping appraise and sell of a ton of his father's gear. this is not my picture, but the pedal is identical. It sounds fantastic, works as it should.

Link Removed

if you aren't familiar, it has no LED indicator, and can only run on a 9v that is accessible through the 4 screw-back-plate. I'm jonesin to get it on my board, but I don't think it'll be first in chain, and I'm assuming the battery will drain if a plug is in the input.

how do you all work with old pedals like this? I don't want to mod or drill the enclosure.

 

[skycruiser]

Put in a battery and unplug when you're not using it? Seems like you'd have to mod the enclosure to put in a kill switch, if that's the type of mod you're looking for.
I love the way the paint on these old MXR ages. Looks great.

 

[bassbrad]

I used something I made similar to this for well over a decade on my vintage NGLD, purchased new in 1978 that was my buffer amp.
CBAT 1 SPOT Battery Clip Converter | Sweetwater

 

[MYLOWFREQ]

We had one of these in our studio. I thought it was lacking the low end. It is possible that it is band-pass.