There is of course a global volume setting affecting all patches at once. However, remember, this does not - and actually should not - resolve your issue. Why?
The global menu does allow you to set a global volume level, the so-called master level. Yet, this does - as you would expect from a global setting make all patches at the same time louder or less loud. Thus individual volume differences among patches are of course retained, since the global level affects all patches in the same way. Only if there would be a global edit command to change all volume settings of all patches to the very same volume at once could you get rid of the level differences among the patches. I do not know of such a command in the Edit & Share software, BTW the only place where I could imagine such a command could be available for currently selected patches. Moreover, volume perception may differ from effect to effect, meaning, that a mechanical setting to the very same level may not really accomplish what you are looking for and you would need to adjust the volume of each patch anyway. But I admit, having such a command available might be useful nevertheless (at least for the B3, since it is the only one that can be edited via software running on the PC).
Unfortunately, as a consequence you need to adjust volume levels of all patches individually. I know of no other technique. This is typically done in the so-called Total menu, where you can set the Patch level. But the level of an individual patch as actually heard by you does not only depend on the total level, i.e. the patch level. It also depends on the level each effect of the 3 (B3) or 4 (MS-B60) has and whether that particular effect is on or off within your patch. To make sure levels are set to a useful value, I adjusted the level of every effect in any patch individually. For some this means tweaking gain or output level of an amp simulation or adjusting the effect/dry signal ratio. For some patches it may already be fine to only tweak the overall output level or the balance parameter of the patch in the total menu. For others it is the gains or output levels or the balance of individual components of the patch that need to be adjusted first. Unfortunately, with such flexible and powerful devices as the B3 there are many parameters that can affect the volume you hear in the end! The downside of the coin if you will.
I have adjusted the volume for all my patches (including all their 3 effects) I regularly use individually. I connected the B3 to my computer, having plugged in one of my basses and listening through headphones. And then going through all patches, one by one, tweaking the volume of every effect within the patch again individually, one by one, till all levels are the same, i.e. roughly at unity. On the computer I used some software (e.g. Bias Peak) showing me a large level meter, again as a reference point or starting point, respectively, for the actual tweaking. As a result I have the freedom to engage effects of a given patch in any combination, without altering the volume dramatically. I have my total volume of any patch basically at 100 and the master volume of my B3 set to 100 as a starting point. Then I tweak further, depending on balance and level of each effect. All these settings are AFAIK unavoidable, since your ears are the decisive final judge of really having comparable output levels. Level perception is partly a psychological phenomenon where mere dB values are not good enough to tell the entire story and very final level adjustments may have to be made on actual stage with amp (or FOH) and actual instruments playing.
I hope these explanations help to better understand what a B3 (or MS-60B) does and how to adjust the volume settings for full freedom to switch on the fly effects on and off of the current patch and/or to advance from one patch to the next without getting too big differences in the volume.
Cheers,
Andreas flf
