Without scenes, your only options are:
1. Set up the same echo and the same reverb at the end of the chain in your patches, regularly; and then set up for seamless patch-changes per the manual (or, as an alternative, use an outboard unit for the final echoes and reverbs of your signal chain, and DON'T send program changes to it);
and,
2. Have 2 different, duplicate rigs, and use a MIDI-controlled mixing device (like a SoundSculpture Switchblade) to crossfade from one to the other every time you change from one preset to another. It would be an intricate little dance of crossfading and program-changing, like this:
- at the start: you're on Preset 001 for both rigs, and the mixer has Rig A at 100% and Rig B at 0%;
- step 1: send a program change to Rig B, changing it to Preset 002;
- step 2: begin a crossfade, increasing the mixer-level of Rig B from 0% to 100% over 500ms, while decreasing Rig A from 100% to 0% over the same time interval;
- step 3: after 500ms, when Rig A reaches 0%, send a program change to Rig A, changing it to Preset 002;
- step 4: begin a reverse-crossfade, decreasing the mixer-level of Rig B from 100% to 0% over 100ms, while increasing Rig A from 0% to 100% over the same time interval (this returns your mixer status to where it was at the start, thus prepping you for any future program-changes;
This same little dance would then be performed again for any successive program changes; e.g., changing from Preset 002 to 003, or from 003 back to 001.
That's pretty much it.
The latter option is much more perfect, and gives you the advantage of taking a spare rig with you at all times.
The former option is cheaper and less-complex, but, it won't be perfectly smooth. (It's the best you can get without using scenes, however.)
