Clean Boost other than Boosta Grande?

There's tons of 'em, but for $50, the only one I can think of is Ehx LPB-1. it might be more, idk. For a sweet, super clean 24dB, look at creation Audio Mk4.23. Not cheap, but NO NOISE, and no color.

 

Ohnoho Blowing Up!, or a Noisemaker FX A-Ok?

 

Any bass equalizer pedal is also a boost cut pedal.

 

Check out Barbers, Launch Pad. Up to 20db of clean boost... Also, used as, A,B, or Y... Has gain and 2 volume... Excellent quality

 

EHX LPB-1 or LPB 2ube

 

LPB-1 is a great pedal, it's not 100% perfectly transparent when you are listening in a bedroom situation. But for all intents and purposes I would say it's transparent. I used to use it to juice up my 400+ and it was awesome. Plus they are only about $40 new.

 

The most natural sounding one I've tried is the Xotic EP boost

 

JHS Bass Preamp-overdrive.
This is the left side of there Pandamoniam Pedal.
it is based on a early SVT, nice clean overdrive, boost.
I use this all the time.

 

I don;t know what you mean by "natural" but the EP Booster is a significantly colored "clone" of an echoplex preamp. It's a clean boost, but it certainly isn't a flat or transparent boost.

On the used market, the best clean boost for bass I can think of is actually the Boost and Comp-cut modes on a fulltone bassdrive. ($100 or less)

 

JHS Bass Bomb Boost. Completely clean, and handmade. Used they go for around 80$.

 

An EQ pedal. Used, if necessary. Giving you the additional benefit of boosting individual frequency bands, if desired.

 

Mxr/custom audio electronics Boost/Line Driver. Best one out there..

 

The Boosta Grande is garbage, colors the sound a ton.

I got the Creation Audio MK.4.23 Boost, excellent pedal. Completely transparent, tons of boost, made in the USA it's great!!!!!