Which volume pedal to use in F5- fx loop?

Looking at the Ernie Ball Jr series...does it matter which model? I've read that for guitar, you generally want the "passive" version of this pedal, but then I understand that using the "active" version (which has a diff pot value) will allow for a smoother taper.

Would like to buy a single volume pedal, so that I can use it out in front of the amp (other amps).

Thoughts?

As I understand it, all EB volume pedals are passive, in that they have no active (battery-powered) circuitry. The "passive" pot is like 250k, and is designed for passive pickups, which are high-impedance out. The "active" pot is like 25k, and is for guitars with active pickups that can drive a lower resistance, as well as for expression pedal uses.

The pot value does not indicate smoothness. The lower the value, the lower the noise, so the 25k volume pedal will be a bit lower noise. But it will be terrible if you drive it with a guitar that has passive pickups, because it will load the pickups and lower the volume and kill the treble. It is also a problem to drive a 25k volume pedal with an FX loop out, because many amps have a pretty high output impedance on the FX send, as it is not buffered. Most Mesa amps have this problem. You are probably better off all around with a high resistance pot.

The TAPER controls the smoothness of the pedal sweep. A linear taper will be not sound very smooth. An audio, or logarithmic, taper will sound smoother. This is because we hear relative volume as a logarithm, as in dB.

They are all passive, with no batteries. The 25K is recommended for use between the guitar and amp when using active pickups.
Use the 6181 (25K) pedal in the FX loop.
Use the high impedance 6180 (250K) pedal between a guitar (with passive pickups) and the amp input.

I'm not sure how it will work with the F-series parallel loop, but I've used the 25K in a Mark III serial loop with zero issues.
It acts as a foot controlled master volume.

My experience is based on stock American Std. Strats and Teles, all passive single coil and Noiseless pickups, passive humbucker equipped PRS and Gibsons, and various pedals with garden variety cables. Any and all other gear you are using may affect your mileage.