yone make a delay that senses input signal....

[Mick Bailey]

If I was to build a box to do this I'd make the parallel loop part of the circuit. I think the main difference is that with a voltage controlled crossfader you can set the delay levels precisely to what you want. For an extreme example, you could have an inverse delay response off the guitar's volume control so that you go from 100% wet with the guitar on zero, to 100% dry with the guitar on 10. Or anywhere you fancy. Or the reverse of that. With a compressor (apart from the altered dynamics of the wet signal), I think there would always be a compromise and some limit to how the perceived delay mix would alter with signal volume. With daz's setup his delay disappears with the guitar on 5, but my setup doesn't do that - my first task is to replicate that situation. I think My Kramer Pacer has a treble bypass cap, and I'll dig out my Laney AOR 30 for a more representative amp.