Thanks for your replies. My unit produces great flange and chorus fx, but absolutely no audible repeats! The chip is a BD3207, which I think offers a less impressive slow delay, but can reach faster clock speeds. This may be case of individual chips behaving slightly different from each other. I am not sure.
By contrast, I have an Akai analog delay guitar fx pedal which delivers impressive echoes. It was inexpensive, but sounds great. I also have a spare 6HP Blank panel and some 1/4 inch and 3.5mm jack sockets. I will make a basic 'patch bay' so I can run my modular sources through the Akai pedal for longer delays, and save the 1-188 for modulation effects.
Cheers,
Blair