how to build a pre-amp?

[yano]

I want to make a pre-amp for my bass (and/or other instruments) so that I can connect it to my home or car stereo.

I'm considering simply designing my own. Would it be a better bet to use something like a LM386-3 (I have one lying around) or should i just use an op-amp (the only ones I have are NE5532s).

Also, how closely could I base this off of a headphone amp?

Thanks in advance!

[Hal]

an lm386 is a power amp chip.... i wouldn't use it in a preamp.  An opamp would work, and so would a simple NPN boost or MOSFET boost...pretty much any "boost" is a preamp.....

[brett]

Hi.
Here's a good pre-amp project.
http://www.tonepad.com/project.asp?id=6
Your NE5532 would work great in this.

cheers

[brett]

PS You'll need to boost the bass a bit and the treble a lot to get a "normal" tone out of a hi-fi or other stereo.

[Kleber AG]

Hello
I must say (IMHO) that THIS:
http://www.geofex.com/circuits/Adjusticator.gif
This is the best one I've tried for this kind of aplications (preamps).

It is better with the 5532 opamps, and man the big surprise is it drives my 4x12 cab really loud for bedroom volumes and really nice sounding...

I've added a baxandall hi/lo active tone stack just before the adjusticator and it works like charm...  

Thanks a lot RG for such a great tool circuit, I believe this circuit block (adjusticator) could be used for many other things with some additions, changes etc, really powerfull thing.

I use it to drive a POWER amp with my pedals

Thanks
Kleber AG

[Gilles C]

I like this one.

http://www.albertkreuzer.com/preamp.htm

More parts, but quite versatile

[RDV]

Here's a couple of super simple preamps. One is a Blackfire stage. One is one I've drawn up out of my pea brain.





Regards

RDV

[brett]

Hi.
Ricky's pre-amp is a nice design, but has low input impedance.  Easily improved by swapping that 100k resistor (connecting to Vr) with a 1M resistor.
cheers

[RDV]

I fixed. Computer smoking. Eyes crossed. I go bed now.

Night night.

RDV

[Kleber AG]

Hello Gilles!

That one you posted got my curiosity...
:lol:
Have you built that?
Tried with guitar or bass?
How does it sounds?
Totally clean?

Please!
Kleber AG

[Gilles C]

<<<Have you built that?
Tried with guitar or bass?
How does it sounds?
Totally clean? >>>

I didn't tried it, but he had good reports a while ago from some people who built it.

I tried only the preamp part with  my guitar.

I always prefered to use JFETs in the first part of a preamp, to get more signal, then use an opamp for the second part of the circuit. And that's what he does. So...