There are a few theories out there as to what type of reverb unit David Gilmour of Pink Floyd used on his classic guitar tone. Some say it was a Binson Echorec, others say it was an Electro-Harmonix Memory Man. The truth is, we may never know for sure. However, we do know that Gilmour's reverb had a huge impact on his sound, and helped him create some of the most iconic guitar tones in rock history. So, whether you're a Pink Floyd fan or not, if you're looking for that classic reverb sound, you'll want to check out either the Binson Echorec or the Electro-Harmonix Memory Man. Both of these units are highly revered for their ability to create lush, atmospheric reverbs that can truly transform your sound. So, if you're looking to add some Gilmour-esque magic to your own guitar playing, either of these reverb units will do the trick.