For my pedal designs I’ve opted to omit the battery compartment for several reasons, none of them directly relating to sound. In no particular order:
- Batteries are environmentally unsound. Batteries contain acid and heavy metals that end up in landfills, in soil, and in the oceans. All my pedals are built with RoHS compliant parts; batteries don’t make sense.
- Batteries are rarely needed. Given the ubiquity of 9VDC center-negative power supplies, batteries are, mostly, unnecessary and for those times when you require a battery, there are options available. eg. https://pedaltrain.com/products/pt-vt3
- Batteries are unreliable. My pedals are built specifically for the professional musician and pros cannot risk battery failure.
- Batteries become an ongoing cost; it doesn’t make sense to replace a $3-5 dollar battery after every few hours of playing.
- Batteries leak. Everyone I know has had the same experience: you open up a pedal that’s been idle for many months and see a battery that’s leaked inside the compartment (ugh).