David's MXR Digital Delay rack mount is seen in this photograph from the '70's.

"We also have an old MXR DDL digital delay unit built into a rack unit. It has a digital readout, but it's really nowhere close to being accurate. Dave likes it because even though it's a digital unit, it still sounds a little dirty, like a tape unit." - Phil Taylor, David Gilmour's guitar tech.

This vintage effects processor was sold on Billy Corgan’s official Reverb.com shop.

In 1977, Roger Waters, along with the band, transitioned from using Binson Echorec 2 units to MXR M-113 Digital Delay devices. These rackmount digital delays typically featured a 320 ms delay chip, with an expansion model offering up to 1.28 seconds of delay. While specific details about Waters' setup aren't mentioned, it's noted that David Gilmour's rig included two MXR Digital Delay units and two upgraded MXR Digital Delay System II units, highlighting the band's integration of advanced delay effects during that period. This information is sourced from Watersish.com.

As seen in this video, Eric Johnson runs a rack-mount MXR Digital Delay that feeds into one of his Marshall Amplifiers. According to Johnson, the Delay unit "feeds the top cabinet for dirty rhythm," he says at (2:20).

I've got an MXR Digital Delay, which I put through one amp, leaving the other amp clean [...]

In this pic you can spot the MXR Digital Delay

In the video "Melvins @ UCLA 3/3/1993 (FULL SHOW)" filmed by HORNSS, Buzz Osborne can be seen using the MXR M-113 Digital Delay, visible at the very top of his equipment rack.

Used with Parliament and Funkadelic, as mentioned by Collins in this excerpt from a 1979 Guitar Player interview as transcribed TalkBass here and here from a reprint in Bass Heroes: Styles, Stories & Secrets of 30 Great Bass Players.

What kind of amps do you use in your setup?

The entire system is divided into three different parts - high, mid, and low. But we're not just talking about amplification, we're talking about the effects in each part. On my highs I use a Big Muff fuzz, a Mu-tron III [envelope-following filter], an MXR digital delay, a Morley Fuzz/Wah, a Morley Power Wah, and an Eventide Harmonizer. The Harmonizer sits in a case that looks like R2D2 from Star Wars. It looks just like a little robot, so I call it R2FunkU. There's a sign hanging on it that says, "Can I Play?" Inside of it, there's also a keyboard for the Harmonizer that enables me to preset harmonized intervals to what I'm playing. That way I can play a note and have a fifth or a third coming out at the same time.

All of that equipment just for the highs?

Right. For the mids, I have a Big Muff fuzz, a Mu-tron III, and an MXR digital delay. On the lows, I use a Mu-tron Octave Divider, two Roland Space Echos, a Big Muff fuzz, and a Mu-tron III. I keep all my effects in one box called the Space Case. The highs and mids each have an Alembic preamp, two Crown DC-300A amps, and four Cerwin-Vega speaker cabinets.

What's in each cabinet?

The cabinets used for the highs are called V-32s. They have two 12s, one midrange horn, and two tweeters. The midrange cabinets are basically the same, except there's one 15" speaker instead of two 12s. Those are called V-34s. On the bottom end are three Acoustic 370 heads and six Cerwin-Vega cabinets. Two have one 18" speaker and one 12", two more have an 18 and a 10, and two have one 18" and an 8.

Isn't that a lot of equipment for onstage?

I don't play it that loud. I've just got it there so that I don't have to strain the equipment and everybody can hear. As a matter of fact, the whole stage is set up like that. The guitar player, the keyboard player, everybody is set up like that so there is no real strain.

The MXR Digital Delay can (quickly) be seen as the camera pans up at 6:46 in this video with Future Music Magazine.

"MXR Digital delay:

Apparently used in a live show at the Palladium to replace the EC-3 that was "rather noisy"".

Musical artist quickly, quickly uses the MXR M-113 Digital Delay, as evidenced by a post on Instagram by user qqitemstorage with the caption "Current Station."

"Live he used an MXR digital delay, the Phoenix Systems flanger and a volume pedal."