How to get crunch out a Marshall JCM800?

[phoenix_555]

Yoo,

I've read on some forums that people can get a crunchy sound out of their marshall JCM 800 bass(1992 model)
Its been told to crank up your master volume somewhere from 7 to 10.
But I haven't found that crunchy sound despite turning the volume up and playing with the knobs.
I use 3 preamp 12AX7 no name tubes and 4 sovtek tubes.
Any advice or maybe a demo?

[chillerthanmost]

Don't quote me but last I remember those mid to late 80's JCM 800 Super Bass models had an entirely different circuit than the traditional JMP or earlier SuperBass. Most people usually use a pedal to push the model you have into overdrive.
If it's the four input model, have you tried to crank the volumes and jump the channels to get some bite? If its the master volume model, have you tried cranking the preamp volume?

What cab and bass are you using?

[AdamR]

a lot of volume