Sounds like you've tried Googleing this.
Did you try re-wording your query?
I sometimes have to reword my Google searches several times to hit on the key words that Google connects their information to.
I find it hard to believe that somebody, somewhere, hasn't posted information about what you're looking for.
Perhaps you need to be more circuit specific? Or even something less specific in your query to open-up new search parameters, and then follow what becomes available after that?
Maybe zeroing-in on audio amplification or guitar centric requests. Something more identified to your specific application.
I use a commercial reverb on my stereo audio amplifier, but don't know anything about adding reverb to a guitar amplifier.
With all of the guitar enthusiasts out there, there's just gotta be information on bass-specific reverb circuits. You just need to use different wording in your Google searches.
(I would think)
I just Googled 'do it yourself guitar reverb circuits', for example, and got plenty of hits.
