[sdiy] Preamp Module

[Andre Majorel]

On 2002-03-12 18:00 -0500, George Kisslak wrote:

> I've been thinking of building an audio preamp module for my MOTM setup, to
> hold me over until Paul releases his planned module.  A simple inverting-amp
> and inverting-follower design is what I was thinking.  (I think I said that
> right. :)  A variable gain control and an input impedance selection switch
> would be bonus (but I don't know if I'm sharp enough to pull that off).
> The input devices are: coil-pickup guitar, line-in, and piezoelectric
> transducer.
> 
> So I'm wondering, which op-amp(s) might be best for this application?  I
> know this is probably trivial to most of you, but I'm still ramping up the
> learning curve.  I've seen OP275/285, LM833, TL081/71/51, and RC4558 used
> successfully in various designs.

Amateur opinion : 4558 doesn't have a terrific reputation. For a
preamp, low noise is important so a 5532 might be good.

Also, the characteristics of the preamp might depend on the
source. I'm told that electric guitars need a very high input
impedance (> 100 k) for best results.

-- 
André Majorel <amajorel at teaser.fr>
http://www.teaser.fr/~amajorel/