[LAU] OT: Guitar level- Mic or Line?

[Andre Majorel]

On 2008-05-27 22:00 +0100, Simon Williams wrote:
> Fons Adriaensen wrote:

> > Use an active DI-box, in particular if the guitar output has
> > to be split for a guitar amp as well.
> 
> What if I can't afford DI-boxes? Which is best to use?

Try it and see but I bet they both will sound muffled. If you have
a bipolar supply hanging around, you can make an unbalanced buffer
for cheap.

Tip of jack from guitar to ground via a 1 M to 5 M resistor and to
the non-inverting input of a TL071. Output of TL071 to its
inverting input and to a 220 ohm resistor. Other end of resistor
to tip of jack to line input. Leave the offset adjust pins
unconnected. Sleeve of both jacks to ground.

                              ^ +15 V
                              |
                         -----------
                        |   _ |     |
                        | 2| -_7    |
                         --|-  -_6  |   220
                           |    _---+--^v^v------\  /|  TO
     FROM  |\  /-------+---|+ _- TL071            \/ |  LINE
   GUITAR  | \/        |  3|_-|4              _______|  INPUT
  OR BASS  |_______    <      |              |
                   |   > 1~5M |             ---
                  ---  <      v -15 V
                       |
                      ---

You could surely do something similar with a unipolar supply (9 V
battery or wall wart) but I don't know how. There is probably a
bipolar supply inside your mixer, though. If it doesn't exceed
+/-18 V, you could use that. Shouldn't be a problem, a TL071 draws
very little current.

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