the Burton scream.

[Sec-Def]

I'm trying to recreate cliff burtons distorted bass wah sound.
now, I was always under the impression (based on my guitar playing experience) that it was the result of putting a distortion pedal (or using the f\x loops on a guitar amp) before the wah pedal.
thus the wah which acts like a notch filter notches up a bunch of distorted square waves
giving it that screaming sound. I'm currently trying this but to no avail.
the sound I'm getting is more the Jason newstead blouch sound.
I would also note that all of this is done on a righty slammer bass with a tone knob+vol knobs.
any thoughts?
newstead: cue to about 5:00
http://www.youtube.com/watch?v=JSpz70OOxYs
butron:
http://www.youtube.com/watch?v=7_wGFfrJv4Y

[Jeroen]

I always thought Cliff Burton used an old Morley Power Wah Fuzz, a wah with a built-in fuzz. They're capable of incredible amounts of noise.

[Sec-Def]

thanks for the input.
I tried putting before the amp and is sounds a bit more a screamish.