Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Solid State => Topic started by: bigsbybender on February 02, 2009, 06:28:21 pm

Title: Bass Guitar onboard preamps
Post by: bigsbybender on February 02, 2009, 06:28:21 pm

Gentlemen,

I'm looking into building an onboard Bass preamplifer for a guy.  This is for a bass that at one time had active circuitry, so there is space to put something either OPAMP or JFET based in there.

Essentially what I got is a pair of Jazz Bass style P/ups. Volume, Mixer pot, and a Bass/Treble stacked pot.  I need a boost in there to get him into funkier slap territory like it was supposed to have. Anybody got any ideas for a small preamp that I could build as an onboard preamp? I have 1 9v Battery as a power source.

Here is what google is telling me....

http://www.diyguitarist.com/Guitars/OA-GuitarPreamp.htm
http://www.dutchforce.com/~eforum/index.php?s=a152d175e7ea4bbe0406a171a661fc3c&showtopic=23166

http://www.diyaudio.com/forums/showthread/t-134061.html

Any thoughts or Opinions?

j.

Title: Re: Bass Guitar onboard preamps
Post by: JayB on February 06, 2009, 04:55:05 pm

I would do the three band eq thing but all you would need is an eq pedal. I don't know. Active pickups with treble, mid and bass knobs would be the tits. I'm always adjusting the tone control on my Fender p-bass for different tones and wishing I could get a little more out of it. Sometimes I wish I could get a little brighter at times and sometimes with the treble cut out for a fat bass sound. Or the mids cut out for a cool acoustic sounding tone.

Title: Re: Bass Guitar onboard preamps
Post by: bigsbybender on February 12, 2009, 10:45:28 pm

Well, I'm looking at these 2.   I have to build them in such a way to cram them in the Bass Guitar's control cavity.... One is FET based and the other uses a common OPAMP.  I need to know opinions of which would be better...I can look at a tube schemo and guess what something would sound like but not so much with Solid State....Also what would those LEDs do on the OPAMP based preamp?  Looks kind of useless to me.

Title: Re: Bass Guitar onboard preamps
Post by: G._Hoffman on February 13, 2009, 04:55:39 am

It's not hard to make one yourself - the OPA 130 is a really good opamp, for this stuff, though I believe it is only avalible in SOP which is a pain.

That said, I honestly can't think of any reason to make one yourself.  Buy a Bartolini preamp harness - when you factor in your time it will be cheaper, and they sound as good or better than anything else out there.  I use them in pretty much every guitar I build which needs a preamp.



Gabriel