Making A Preamp For A Bass

[Moreau]

Hi there,

I am new to electronics, but have been lurking about. I want to make a bass preamp, and was wondering what aspects go into designing one. I was thinking of a high mid and low boost, and i was going to use a volume knob per pickup. What other elements should I add, or is this enough? would i look for a preamp circuit, like the jfet ones i see, or do i make a boost circuit. what are some good boost circuits i can use to make a preamp? i am new to this and would like to learn more. thanks

[lovekraft]

Try this for a starting point -

Onboard JFET Preamp

Or take a look at the 3-band EQ circuit on page 7 of this datasheet -

TL082. Add a little gain to the first stage, slap a volume control after the output, and you've got instant preamp - you can even delete the input cap and raise that first resistor to about 500K if you're using passive pickups.

[Moreau]

thanks... i am not very familiar with this... "Add a little gain to the first stage, slap a volume control after the output, and you've got instant preamp - you can even delete the input cap and raise that first resistor to about 500K if you're using passive pickups." is this what i need to do to make it a preamp? or is already a preamp? so there is a series of 3 pots with a high, low and mid right? is the boost/cut label another pot? the mods you listed make it more ideal for a bass, or do i need to do them? thanks

[lovekraft]

Here we go again - listen, I am in no way trying to be insulting or denigrating, so you shouldn't take this personally, but I would suggest that if you can't read a schematic well and don't know how to add gain to an op amp circuit, designing and building an onboard preamp may be more of a job than you are capable of completing. Have you built any electronic gear before?

[lovekraft]

The circuit described/drawn in this thread will do what you want (give it a listen), more than likely (sorry, I had forgotten about it, or I'd have mentioned it earlier) - no layout or board, but it's a pretty straight-forward circuit. HTH