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

[Paul Coccoli]

On Thu, May 29, 2008 at 3:39 AM, Andre Majorel <aym-psd at teaser.fr> wrote:
> 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.
>

Wouldn't any non-"True Bypass" stomp box do the same thing?