April 6, 2022

Current Pedal Obsession: Quiet Theory Prelude Reverb/Delay

With all the amazing digital and analog delays and reverbs out there, Prelude is an anomaly of normalcy. It doesn’t get stratospheric in length or ambience, it just sounds like a great-little, 1-second, delay feeding into a musical spring reverb. It’s uses simple PT2399 delay chips and has only basic controls. But really, this box is a marvel of design. Bryan Laurenson of the Indy band Copeland (owner of Quiet Theory) spent two years designing Prelude, beautifully pushing the chips to their limits into spaces they were never designed to venture into.

What’s a PT2399?

This is a digital-delay-on-a-chip that pedal builders use to create an “analog-flavored” delay of 30ms to about 500ms. Through his circuit wizardry Bryan has stretched the Prelude’s PT2399 delay out to 1100ms and it still sounds beautifully gritty, gently compressed and remarkably quiet. The reverb side is built on a Belton Brick module (actually 3 cascading PT2399s with delays between 30-40ms). This module was designed by the legendary Brain Neunaber of Neunaber Audio to mimic the 3 springs in a Fender tank. Laurenson used this to create an uncharacteristicly dry, lingering spring reverb with quiet early reflections that bloom into subtle modulation.

Though the delay can self-oscillate, when cranked most knobs won’t take you beyond sensible levels of volume or ambience and the dry is always at unity. The tone switches are well worked, but players looking for crispy repeats and rampant modulation often associated with the PT2399 may be disappointed. The 3 tone settings are normal, dark and darker. And there’s only the reverb’s inherent modulation to speak of. But if you think this sounds boring, you’re wrong. Many will find this combo is delay and reverb as they’re meant to be.

Here are demos of the reverb, delay and both. All have been set at the brightest settings. The reverb is an excellent example of what a Belton Brick can be. On staccato sounds you can really hear the individual echos of the 3 PT2399 chips.

The delay time has been cranked to max out at about 1100ms, sounding a just a bit longer and more graceful than most delays. At the same time it starts to get lo-fi and gritty, but still has a beauty. With repeats almost to self-oscillation, they still blend nicely.

The combo of delay and reverb blend well, but remain their own effects. Prelude doesn’t cross pollinate them into a de-verb or a re-lay the way many of the more elaborate delay/reverb combos do.

Shifting pitch

A beauty of the way the delay in the Prelude is crafted is how smoothly it reacts to changing the Time knob, momentarily shifting pitch as you manually speed it up or slow it down. (Digital delays can often just make goofy digital noises with what’s in memory as you crank the Time knob.) When repeats are up and the delay is long this pitch speedup or slowdown is an effect within itself. Sorry, no expression jack to do this with a foot controller.

Burst mode

The pedal’s big trick is Burst mode which works best when Trails are on (top toggle to the right). This makes the Delay and/or Reverb footswitch momentary for some unique effects. To turn on Burst mode, tap either footswitch 5 times, hold on the last tap and say “Toto, I don’t think we’re playing with Kansas anymore”. When the LED above it blinks, Momentary is engaged. (Do the same process to go back to Latching mode.)

A practical use of Burst Mode is delay-on-demand. Only what’s recorded when the delay footswitch is held will play back, so repeats can be isolated without adding new audio to the delay. (Very cool with pitch-shift since the pitch doesn’t self-correct.) Or when delaying just the subtle tails by engaging the delay after the attack.

Another cool trick is to use a super-short, high-feedback delay like a reverb and use the Reverb footswitch in Momentary mode to subtly swell in the modulated ambience. Set Time to 8a, Delay Mix to 3p and Feedback to 3p (almost to self-oscillation). Set the Reverb Mix and Decay both to 5p. Play a sustained chord and then hold down the Reverb footswitch. It’s like a 1-spring reverb that blooms into a 4-spring reverb behind your chord.

My take

It’s really nice to have an spring reverb and poetic delay in one box with separate footswitches and controls. In a way it’s a great normalizer of insanity, giving you a predictable delay and reverb to follow your wacky pedals. What makes this pedal so out-of-the-ordinary is that it never gets too far out-of-the-ordinary. And beautifully so.

For the spectators: 9v, true bypass, top-mounted jacks, 1100ms, made in USA


Did Quiet Theory pay me to say this nice stuff? No way. It’s an honest review from someone who uses the pedal. So buying me a coffee is greatly appreciated and keep the candid reviews coming.


Why buy me a coffee? No third-party ads, no affiliate links, no tracking cookies. Just honest content. Thanks.


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