I am wondering if it would be possible to modify the Dirtbaby to have longer delay time by adding a daughter board with a second PT2399 chip akin to the similar addition to the Echo Base. Any suggestions?
it would be possible but it would be a hell of a mod... it would be much easier just to build a ZPDX and use the analog delay mode, it has a very similar feedback section so they will sound very similar.
it would be much cheaper, easier and more reliable to use the premade board, plus you get the extra features for free.