Dr. Scientist Sunny Day Delay

The Dr. Scientist Sunny Day Delay is a compact update of the Canadian builder’s analog-voiced (but actually based on the PT2399 chip) modulated delay design, whose original version, dating back to 2005, was almost twice as big.

Built using almost exactly the same parts as the original (according to GuitarPedalX), the new version replaces the (delay) Level knob with a dry/wet Mix knob, also adding extra Tone and Volume (out) knobs not included in the original, plus a second footswitch that can trigger the modulation section or – used as a momentary switch – ramp up the repeats to the maximum setting.

V2 also has an Expression input that allows remote control of the Mix knob.

We added this pedal to our article about the best tape-style delay pedals.

Dr. Scientist Sunny Day Delay, Builder’s Notes


  • All analog circuit and controls
  • Uniquely designed circuit
  • High quality analog signal path
  • Premium parts and components throughout
  • True Bypass with soft touch relay switching
  • Full control over wet/dry mix
  • Expression pedal control over Mix
  • Buffered Input and Output
  • Top mounted audio and power jacks
  • Designed and handmade in B.C., Canada


  • Delay – Sets the delay time from nearly instant to just over a second
  • Repeats – Sets the number of repeats from 1 to oscillating
  • Tone – Adjust the frequency response of the repeats
  • Mix – Adjusts the balance between the input signal (Dry) and the effect (Wet) signal
  • Mod Depth – Increases the amount of warble in the repeats
  • Mod Rate – Sets the speed of the modulation
  • Volume – Controls the overall signal level
  • Mod/Osc Footswitch – Either turns the modulation on/off or can be held for maximum repeats
  • Bypass – Engage or disengage the effect