Recommendations for an octave pedal

[Michedelic]

TC Sub’n’Up is a contender; the mini version works well.

 

[Stubb]

Octron is a great call for this purpose.

 

[bassmonkeee]

Darkglass KAAMOS. Best and most versatile octave pedal with added distortion if needed. A bit pricey, but well worth it.

That;s what I have, as well. The best sub tones I've ever heard, and it tracks down to C# on my B strings, and it has no trouble with open strings. You can also switch it to polyphonic. While it doesn't have octave up, it does have an effects loop that you specify which side it hits. You could put an octave up only pedal (like the EQD Tentacle) in the non-sub side and toggle it on independently of the sub. It even has a dedicated sub out you can send to the PA or a separate rig if you really want to blow people's pants off.

And, yeah--pricey, but worth every cent.