MIDI -- Does Velocity Value = Note Volume?

Hi. I recorded a simple MIDI bass line through Scarbee PreBass on a MIDI keyboard. Generally, it sounds pretty good in terms of consistent volume levels from note to note -- except, for one here and there.
 
I went into PRV and was able to raise the Velocity of those notes, but even at the max (127), the notes aren't as loud as other notes, which are even at a lower velocity. I don't understand that. Is that something I could address with compression leveling once I bounce the MIDI clip to audio? Is that a good approach?
 
Can one of our generous MIDI gurus provide some guidance? Thank you! 
Billy

Velocity is a numerical value with no fixed relationship whatever with any particular "volume" that it will produce. You can not even say for certain that the power of the output will increase with higher numbers, since the velocity value can be set to control other parameters of an instrument than volume, and conceivably an instrument can be set to produce a lower output to a higher velocity. That latter setting might be useful for example if you are using a controller to send to two instruments and you want the output of one to duck or drop as the output to the other increases.
 
If you want to control the output at the highest level the velocity value will control, you can usually do it in settings for the instrument itself. The same can often be said of the relative relationship of different velocity values via settings like a "velocity curve." There is no reason to assume that an instrument's output will invariably follow a linear relationship to the velocity number. Absent settings in the instrument to control its response to velocity, you will need to increase the gain in the recorded audio track or playback system. 

Midi Volume and Velocity are different in some ways. Volume is obvious. Velocity depends on the player. 
Normally velocity is louder but it's intent is to also add a realistic change to the timber of the sound. Like playing a piano softly will have different overtones than if hit hard. 
Not all instruments take advantage of this and it depends on the extent of sampling. 
Bass VST's seem basic and I've never experienced any change in timber with the few I've used.  
I would try using the Velocity scaling set 100 and see if it works. Normally it always set all notes to 100 and they will all sound the same. If it doesn't then myself I'd blame the VST and complain to the company.  

Thank you to everyone that responded. It was puzzling, but I figured it out (I think!) The volume issue arose when I was going from a "B" to an "A" note. So, apparently, Pre-Bass does a slide (legato?) between notes that are that close an interval. I need to completely release the "B" note before hitting the "A". It was a legato thing, which it seems loses the power of the "A" note that is slid (slided?) down to. 
 
Seems I have to exactly release the "B" before I hit the "A."