OK, I ordered one. You are all now officially responsible for my future happiness or lack thereof.
How many of you are using the/a expression pedal with the B3n? How much does it add to the usefulness?
Which pedals will work best with it, is Zoom's own FP02M the best bet?
To follow up on my promise: I have now measured what my FP02 pedals do: Between tip and sleeve you have a resistance of 86 kOhm. Between ring and sleeve you have indeed 0 kOhm at minimum position of the pedal (heel down). That resistance goes up to 82.5 kOhm when the pedal is at max position (toes down). Moreover, the resistance between tip and ring behaves accordingly, showing at minimum pedal position 86 kOhm, but at maximum pedal position not quite 0, but still about 7 kOhm. That's all folks (what this simple pedal does).
Finally, you wondered why that simple pedal can control a parameter of an effect, as it does when connected to the B3. Think about it, this has very little to do with the pedal itself, since that needs only to "send" information about the foot position, nothing else. The interpretation of that position as defined by a resistance is then fully done within the B3 or B3n, i.e. by the software (provided as firmware). Theoretically any parameter can then be controlled if the programming is done accordingly.
Unfortunately the B3n offers here in some sense less and in another more functionality. More flexibility comes from the fact that the B3n software treats the pedal as an effect unit as any other in the signal chain out of the 7 slots supported. This means in the B3n you are free to insert the pedal anywhere in that signal chain as controlling volume, or a wah effect, or a resonance filter, or a pitch bender. On the other hand, the pedal can control only the particular signal it receives from the chain where it is inserted, nothing else, since the "pedal unit" can logically no longer be connected to a specific other effect in the signal chain as is possible with the B3. Theoretically Zoom could release another pedal effect unit, which could again do that, but I doubt this, since such a pedal effect unit would mean the pedal is completely outside the actual signal chain. This would logically defy the insertion in the signal chain, making no longer sense and might confuse users. Thus I fear Zoom will not offer such a pedal unit for download.
With the B3 there is another solution offered: The pedal is not an effect unit and can therefore be inserted only at predefined positions. They are the begin, i.e. controlling input volume, or the end, i.e. output volume or thirdly balance between dry and effect signal, of the signal chain. There is a fourth, quite powerful option, where the pedal can be connected to one of the other 3 units in the signal chain controlling a particular parameter of that unit. For an equalizer unit it may be the bass tone control, for an amp simulation the gain or for a SFX some dominant parameter of that unit. While this is all somewhat limited, since you can control only one of the three units at a time and only a predefined parameter of that unit, in practice it is IMHO nevertheless quite powerful and offers more flexibility to control an effects behavior than what is possible with the B3n. Admitted, on my brand new B3n I have not experimented much with the resonance filter option for the pedal, which might allow to accomplish similar sounds as are possible with the B3. But that would need to be tested.
Hope this is nevertheless already helpful.
Cheers, Andreas flf