Adding drive to bass amp?

[GainFreak]

Hi,

I'd like to add some drive to an existing bass amp. Currently the preamp is a Fender like configuration - triode - tone stack - triode. Is it a good idea to add one more tube /first triode will be common/ and build a drive section /LF cut at 500-800Hz for example/ for the drive sound which will be mixed with the clean bass sound?
Any other ideas and comments will be appreciated.

[jrfrond]

The first thing I'd have to question here is: why you would LPF the signal chain anywhere in a bass amp at 500-800Hz?

You just need gain to overdrive the first input stage. What I see in my head is an DRIVE switch that does three things: 1) switches pre and post-drive stage to enable drive, 2) attenuates the signal post-preamp (perhaps engaging a MV control) to maintain output level, and 3) engages a post-2nd stage LPF filter (fixed or variable one-knob control) to smooth-out the tone.

[GainFreak]

The first thing I'd have to question here is: why you would LPF the signal chain anywhere in a bass amp at 500-800Hz?

This is how it's usually done in a bass drive pedal although I'm not sure about the LF frequency.