Boss DD-2 Digital Delay - Standard DDL. Nothing fancy. Good lowfi alternative to the later boss delays. Basically is a DM-3 with a Digital chip instead of a BBD. 800ms of delay time max. The Hold is kind usless, as you have to hold down the switch to use it. Does not self oscillate without a feedback loop, only pitchshifts. Does not trail.
Boss DD-3 Digital Delay - see dd-3. Name of the DD-2 was changed because chip costs went down. Slightly different layout.
Boss DD-5 Digital Delay - 11 modes. rhythmic modes are rarely used by anyone excpet edge wannbies. The reverse does not do 100% wet but it does pitchshift and can be modded. Pitchshift is slightly disabled but if you try hard you can get it to do it on mode one, along with self oscillate. Firstcompact pedal I can think of with tap tempo. IMO it is a bad sounding delay with good features. I found it did really strange things to my signal path. Then again, I would also like to get on again to try it. max delay 2 seconds. Bypass trails(this is the first series to introduce that feature in pedals, along with the PS-3 and RV-3)
Boss DD-6 Digital Delay - Nice DDl. The Warp mode is great! Instant max feedabck and weirdness. the pitchshifting is artificial sounding on eit, less so then a DL-4...more like a Digidelay. The tap tempo is use by holding down the pedal for 2 seconds to put it in tap mode. really bad design. Hold function is useful for the first time at a huge 5.2 seconds. Max long delay time I beleive is 2.6 seconds. Does pitchshift and oscillate. Reverse does 100% wet poopie. Bypass trails
Boss DD-20 Digital Delay - the king. Doesnt pitchshift nicely or oscillate like a analog delay, but you can get some twisted sounds out of it anyway. A LOT of control over the tone of the delay, and the type. Huge delay times, twist and warp for ****s and giggles, tap tempo, a 23 second looper, good reverse sounds(100% wet) and a LCD that read the delay time. Infinite possibilities. A amazing delay MACHINE. Bypass trails the dealy
Boss DM-2 Delay - Nice analog delay. grungy in a cool way. 300ms of dleay, can be twaked to about 4 but get ugly at about 320ms. great self oscillating and just a beautiful and classic analog tone. Good pedal. One of my favs
Boss DM-3 Delay - Nice analog. Cleaner then the DM-2, and offers 450 ms of time. A little tamer then the DM-2 but a great alternative if you need more time and something a touch cleaner. the guts went on to serve the DD-2 and DD-3. I would love a DM-3 as 420ms seems to be my analog delay number.
Boss DSD-2 Digital Sampler/Delay - DD-2 with a usless trigger mode(800ms + trigger = usless)
Boss DSD-3 Digital Sampler/Delay - Same story as the DD-2/3. Price came down. see dsd-2.
Boss PS-2 Digital Pitch Shifter/Delay - One of the few boss boxes to bleed the bypass. This thing is UGLY. Low fi hell, self oscillation machine. For year this was boss's only 2 second delay in pedal form(they had racks). the pitchshifter is a joke. the delay pitchshifting and oscillation are AMAZING. So ugly. the boss 1/3 rack series are all this quality level(which is why I stockpile them for oscillation, and they all have useful hold functions). this this is a noise machine.