I've tested this pedal every way possible and the hiss is always there. My take is that the op amps/processors are generating the noise and are amplified as you increase the "Wet" signal. I've tested to the extent of not plugging anything into the input and mono out (out switch selected as amp) into the amp input and the noise is still present. Also, if you select a patch with modulation, you'll hear the noise modulate per the effect patch. again adjusting the wet/dry increases/decreases the noise level. Again all this tested without a signal input to the time-factor.
