Passive Tone Control in a Pedal

[gadgetgirl]

Take a look at the new EWS Tri-Logic Bass Preamp III (Xotic preamp in a pedal with added features).

 

[seedokebass]

Slyjoe and Megafiddle are getting at why I thought they were not exactly the same. I know I've read things like that but didn't know all the sciency stuff to back it up haha

 

[slyjoe]

Ok, so you're telling me that a passive wiring harness is not an RC circuit? That doesn't make sense to me... All thats there is a resistor (pot) and a capacitor! Sure there's other variables with the pickups but it seems to me like it would still follow that roll off frequency equation fairly closely.. (f = 2π/RC.. I think)

It's an RLC circuit when you take into account the pickups. And you have to take those into account. What happens when you rotate the pot all the way to the end (i.e., 0 resistance)? At what frequency would the rolloff occur?

I've attached a SPICE model of a jazz with SCN pickups as well as the frequency response. Can't get that with just an R and a C.

 

[mcnach]

As the title says... Is there anything readily available? Turning down the treble on an active bass doesn't sound the same. Likewise, I've not been able to get the same result from EQ pedals.

As some have already commented, it's not just a matter of putting a standard passive tone control in a box if your bass is active, but a low pass filter pedal (or a pedal that includes an adjustable LPF) will do something very similar to what a passive tone control does (not exactly the same but close enough). Broughton Audio has a few options, and other companies make various EQ or preamp pedals that include an adjustable LPF.

https://www.broughtonaudio.com/product-page/low-pass-filter

 

[mcnach]

Thanks for your suggestions. The problem with an on-board pre is that I'd need to install one on each of my basses. Hence why I'd prefer something outboard. What about the Markbass booster (I forget its name) with VLE (Vintage Loudspeaker Emulator) control. How similar is that?

If nothing exists it seems like a really obvious, simple and cheap void in the market?

Doh, I forgot about the MarkBass SuperBooster pedal. Indeed, its VLE filter is essentially a LPF. That would be a good option too, only it's discontinued and it's a pretty big pedal, but you get the VLE and VPF filters, footswitchable, plus a very decent DI.

 

[mcnach]

+1 for active/passive switching. I dont know how you feel about modding the bass but why emulate a passive tone if you can just have a passive tone circuit

If the OP is like me, he may want to be able to use the treble roll-off you get from passive tone controls while still having access to the active EQ.

 

[mcnach]

whoa, zombie thread resurrected... how did that happen??? Clearly I was not reading the 'new posts' section... must... imbibe... more... coffee...