Jim,

I asked the same question and never got a response either.  I have a 30 Watt Spider IV with the FBV MKII Express pedal.  I was able to assign custom presets by pressing the channel button down and holding it until it flashed.  Once flashing I could configure the channel to anything I wanted.  Once I did it for all 4 channels I got my configurations in.  What I'd like to figure out is if I can toggle back and forth from my custom presets and factory defaults.  Anyway, hope this helps.

On a Spider IV 75 watt amp model, there are 1A-16D userbank memory slots. (On the Spider IV 30 watt, there's only 4 memory slots).

@ James: you have to save your 2 clean sounds and 2 distorted sounds into any of the 4 channels within a userbank of your choosing. The way to do this is to get one sound dialed in the way you want it to sound. Then, press and hold one of the 4 Channel buttons for at least 3-5 seconds until they blink. At that point, look at the LCD display screen. It should be asking you to select a Userbank # and give you the option to rename the sound, if desired. You can use the Up/Down/Right/Left arrows to navigate (if you want to use a different Userbank, left arrow until the underscore is to the left underneath the Userbank # itself. At that point, Up/Down will go up or down through the 16 userbank numbers). Once you're happy with the Userbank #, press one of the 4 blinking Channel letter buttons to finalize/store the sound to that Userbank/Channel Letter, i.e. 3A or 9C, etc.

You'll want to keep all 4 sounds in the same Userbank #, however because the FBV Express MKII is the smaller of the two controllers and doesn't provide you the footswitch control to go to a different Userbank #. But within the currently selected (via your thumbs on the Up/Down arrows), the FBV Express MKII A, B, C, D switches will allow you to select any of those 4 sound memory locations.

@ Brodr: the 30 watt Spider IV amps only have 4 memory slots, so in your case that's the limit as far as how many sounds can be stored.

If you overwrite one of the "factory defaults", you've replaced it. The only way to do what you last asked would be if the amp had 8 memory slots (4 to retain the 4 factory default sounds and 4 to store your own). Unfortunately that is not the case. But at least I hope this info clarifies that aspect of what the 30 watt amp can and cannot do in regards to saving sound settings.

The FBV Express MKII itself is just a remote control switcher. There are no memory slots inside of it... it's in the amp that you save sound settings to.