AquababyFX TYPE: Delay

The Aquababy is a compact analog delay pedal based on the Boss Dm-2. The project requires 1/8W resistors and wired pots.

The controls on the Aquababy are as follows:

– MIX: Adjusts the ratio of delay vs. clean signal.
– FDBK: Controls the number of delay repeats. Maximum setting induces self-oscillation.
– Delay: Sets the delay time from slap-back to about 300ms.
– Bias: Used to set the proper bias on the input of the MN3005 for clean delay.
– Cancel: Sets the mix of the two delay outputs on the MN3005.
– Clock: Sets the correct clock frequency range produced by the MN3101 to drive the BBD delay lines in the MN3005.

Before starting the project, make the following adjustments:

– Set the mix control at the center position.
– Set the delay at the maximum position.
– Set the FDBK at about 1/3 up.
– Set the BIAS and Cancel trimpots to their center position.

If you have frequency measurement on your DMM, adjust the Clock trimmer to about 6.5kHz while probing either pin2 or pin4 of IC5. If you don’t have this feature, set the Clock trim halfway up.

To calibrate the delay, use an audio probe to check if delay is passing through pin3 of IC3. Adjust the BIAS trimmer until you get delay passing with the least amount of distortion. Confirm that delay is also passing through pin4 of IC3. Adjust the CLOCK trimmer until just before any high pitch whine is heard in the audio path. The clock frequency should be between 6 and 7 kHz.

Unless using an oscilloscope for calibration, leave the Cancel trim in the center position.

Summary created by AI from the original source.