This filter boards combines a raw OTA-C 2-pole filter, combined with a classic lo-fi delay.

The delay parameters are the following:

1. tim (time): Delay time. The delay time is expressed in arbitrary units. Due to parts tolerance, the actual delay time might vary by a few percent, and this parameter is not accurately calibrated. The delay time typically ranges from 30ms (0) to 550ms (127). This parameter has a logarithmic scale, so the intermediate delay time (64) is close to 120ms.
2. lev (level): Delay level. This controls the wet signal level. No delay effect can be heard when this parameter is set to 0.
3. fdb (feedback): Delay feedback. This parameter controls the level of the signal taken at the output of the delay loop and fed back to the input.
4. eq. (fdbck. eq): Feedback tone colour. A simple EQ circuit is present in the feedback loop. When this parameter is set to 0, the signal fed back into the delay is coloured by a low-pass filter with a cutoff of 500 Hz. This causes the echoes to get darker and darker, an effect which is not unlike reverb with short delay times. When this parameter is set to 15, the signal fed back into the delay is coloured by a high-pass filter with a cutoff of 500 Hz. This gives the echoes a "dub" flavour.