thanks for all the replies 
only just seen them, as thread subscription email alerts aren’t working for me 
the pigtronix sounds like it might be a goer. also the ehx 2880/45000. the ehx might have the edge as it has faders to play with dry/loop levels.
- do any of the pigtronix knobs (or midi controllable params) do a simple source/loop wet/dry mix? that and solid midi sync are my 2 main requirements…