The Keeley Memphis Sun – Lo-Fi Reverb, Echo and Double-Tracker is the company's second studio-themed pedal. Like the Keeley 30ms ADT, this pedal gives you a wealth of tones for capturing that classic rock 'n' roll sound as well as sounds you’ve not heard before. It’s neo-vintage. It’s an echo and reverb pedal.

Toggle through the different effects presets:
SLAPBACK 600 – Echo for long delays
SUN MODE – Auto Track-Doubling and slapback with short delays
ROOM – Studio simulation reverb

Both of the ECHO 600 and SUN MODE effects have a Room Reverb.

It’s a one-knob, rock and roll type of room reverb.

Slapback 600
Rock and roll is the devil’s music, right? So, of course Keeley made the delay time up to 666ms to simulate some unearthly echo machine that never really existed. Filtering in the Slackback mode is done in stages. First, it filters the response at 1 kHz, then compress the thing. Remember the concept: pack a bunch of sound in a small room and it compresses. Next, the Memphis Sun filters it again at 1 kHz. The designers added second- and third-order harmonics to this mix to simulate tape response and equipment distortions. Waves folded back on themselves. 

Sun Mode
Automatic Double Tracking (ADT) was not available in the 1950s, but we sneak it in here because it makes a wonderful sound. And, if you lengthen the time, it goes right into slapback territory which is at the heart of Country and Rock and Roll guitar sounds. Like our Keeley 30ms, this pedal will do ADT. The Memphis Sun creates a vintage-voiced double-track in mono. Your guitar-playin’ “Gemini-Twin” has a very warmed-up tone. Adjusting the Time Control lets you easily create anything from Double Tracking to Slapback with up to 180ms of delay time.

Time Delay Time is 0-180ms. For Automatic Double-Tracking set this control at the second mark or lower, 0-30ms. For slapback echo 30-180ms sounds great. The knob markers notate 0, 30, 60, 90, 120, 150 and 180ms.

Regen Modulation for the ADT. Set to OFF for NO Rate or Depth. Increasing this control increases both the Rate and Depth of “Tape” modulation.
Reverb It’s Still Rock-and-Roll Room Reverb to Me

Room
The Room Reverb simulates a small 33-foot by 18-foot asbestos-tiled room so filled with music, the sounds actually get compressed. The designers take into account the frequency response of the mics used back then. The RCA 77 is loosely simulated by a group of filters including a HPF = 300 Hz and LPF = 8 kHz. Many artifacts are incorporated in our room reverb. And second- and third-order harmonics are added to make sure it sounds just right.

Time is the Pre-Delay amount: 0-150ms of pre-delay. This allows for a slapback sound as the first reflections come into focus.

Regen is the Tone control: this is an active filter +/- 10 dB and is centered around 1.1 kHz.
Reverb is the Depth control for the reverberations.

NeoVintage – Low Fidelity. That’s right. This doesn’t sounds like some merry band of pixie nymphs playing digital fiddles in your ear.