lexicon MX 300 [studio echo] for guitar?

[petemoore]

http://www.diystompboxes.com/smfforum/index.php?action=post;board=2.0
  Seems like it's not particularly suited to non-line-in or non-effects-loop usage.
  I tried plugging guitar/stompboxes into it and...it 'works'...sorta.
  Seems grainy or hard' sounding and the attack is delayed...
  Wondering if there's a quick fix or preferred method such as get as...get an effects loop type amplifier to use it with.