Preamplifier

[aguantesoda]

Hola, me llamo guido, y tengo un problema con mi preamplificador...

Queria saber si me pueden ayudar a hacer funcionar este preamplificador, ya que estuve probandolo, pero no pude obtener una calidad razonable de sonido... estoy utilizando el tl082, y queria saber si lo estoy usando bien.
El fin que le voy a dar a este preamplificador es para ponerlo con el bajo, y queria saber tambien si hay que hacerle alguna modificación "extra" para que funcione correctamente.


Hi, I am Guido, And I Have a Problem With my preamplifier....

I want to know if they can help me to make work this preamp, since I was proving(trying) it, but could not obtain a reasonable quality of sound ... I am using the tl082, And I would to know if I using it well.

The end(purpose) that I am going to give to this preamp is for the bass guitar, and I want to know also if it is necessary to do some modification to him(her) "extra" in order that it works correctly with the bass guitar

My english is very poor, but, I wish you can understand me!!.

Here is the circuit.

[kubeek]

Do you have the power supply right? this circuit needs to have +15V and -15V connected. If you don´t have a sufficient supply, you can use two 9V batteries, each one connected to the ground and to the supply pin of the tl082.


BTW: most things in english are reffered to as "it", he and she are used only for people and animals.

[parsecaudio]

Hi aguantesoda

the power supply in your circuit is not present.
The operating voltage of the TL082 is +15 and -15V.

Two bypass capacitors of 100nF polyester must to be added closest to the pin 4 and 8 to ground.

[anatech]

Hi Guido,
VR1 is wired wrong, and you will have all the circuit noise from the tone circuit as there is no attenuation.

What is the problem you are having?

-Chris

[lineup]

Hola, amigo!
aguantesoda
http://www.geocities.com/aguantesoda/

Argentina - spanish.

Have a look, alternatives, good circuits.
http://www.epanorama.net/links/audiocircuits.html
Guitar effect boxes
TL082 is good OP-amp IC, for guitar.
Also TL072.

Where is your music?
mp3 ?

good luck - bona fortuna

[willysan]

Qué es lo que no te gusta del sonido?
Funciona pero con problemas?

What´s the feature you dislike about it?
Does it function at all?

[aguantesoda]

Perdon, si es verdad, olvide decir que la fuente de tension es de
+15 0 -15, ahora, el problema que estoy teniendo, es que cuando a la entrada no hay nada, o cuando pongo el bajo se escucha un ruido bastante molesto y fuerte. Supongo que eso es problema de masa, pero no se bien como resolverlo.
Ahora bien, si cortocircuito la entrada el problema se resuelve, o si le doy entrada desde mi equipo de audio tambien,(es por eso que deduzco el problema de masa), pero la respuesta de salida no es la mejor, sino que esta un poco distorcionada...


Sorry Im forgets to say that the voltage source is +15 0-15,
Now, the problem that I am having, it is that when at the entry there is nothing, or when I put the bass there is listened a troublesome enough and strong noise. I suppose that it is a problem of ground, but I don´t know to solve it. Now then, if short circuit the entry the problem is solved, or if I give it entry from my equipment of audio also(a phillips, only for tests ), (it is because of it that I deduce the problem of ground), but the response of exit is not the best... the output is very distortioned.

[willysan]

Tenés dos problemas separados. Uno es el de masa y probablemente sea un lazo de tierra. En cuanto a la distorsión hay que asegurarse que no este saturando. Poné todas las ganancias al mínimo.

The circuit shows two problems. The first one is probably related to a ground loop. As for the second one, it may be traced to saturation. Try setting every gain control to minimum.

[anatech]

See post #4
Your volume control is wired incorrectly. The gain is very high. You can not use a line level signal to test this preamp. A dynamic mic would work for testing.

-Chris

[aguantesoda]

Desde el bajo ya me fije, pero esta todo cableado correctamente. probando descubri que poniendo una resistencia de 1k entre negativo y masa se reducia el ruido.... pero no mucho..
El problema de masa lo puedo eliminar de alguna manera?