Preamplifier

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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.
 

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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.
 
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.
 
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.
 
Los problemas de tierra son complicados y es necesario tener un esquema detallado del circuito, incluyendo la fuente, dónde está tomada la masa y las pistas de la plaqueta. Con el diagrama que posteaste es insuficiente para decidir el posible origen del problema de masas. Podés agregar una imagen del esquema de la plaqueta y la fuente?

Ground loop problems are rather complex to solve . They largely depend on specific details such as power supply grounding point (or points) and pcb tracks. The image you posted is not detailed enough to suggest a possible cure for your grounding problems.
Could you please post more detailed schematics?
 
Im Sorry anatech, you will right,

I have say :

I have look the bass(guitar), but this one quite wired up correctly. Trying I have found that putting a resistance of 1k between negative and ground it reduce the noise .... but not much..
The problem of ground can I eliminate it somehow?

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?
 
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Hi Guido,
I am trying to understand why there should be a grounding issue between a battery powered preamp and your amp. There is no ground reference.

However, your volume control is not connected properly. The middle terminal (wiper) should feed the next stage. The signal enters at the top, furthest from the common side. Try to rewire the control and see what happens with no signal. Then try a dynamic mic. A line level will overload the first stage you have there.

-Chris
 
Hola WillySan, al fin un argento! (no es por nada, pero es una satisfaccion encontrar a alguien de mi pais en un sitio en ingles!) jaja.

Mira, con respecto a la fuente, el preamplificador lo estoy probando con una fuente regulada, y funciona bien(la fuente, jaja).

Con respecto a la plaqueta, es todo un módulo que estoy armando, con pre y amplificador, todo junto, pero lo estoy probando por partes, ya que estoy experimentando, y no estoy seguro que anda y que no.

A continuacion, te mando el amplificador con el que va acoplado el preamplificador.


Hi WillySan, Al fin un Argentino! (It isn´t for anything, but it is a satisfaction to find someone of my country in a site in English!) jaja.
Look, with regard to the supply, the preamplifier I am proving it with a regular supply, and It works well.
With regard to the circuit, it is the whole module that I am assembling, with pre and amplifier, everything join, but I am proving it on parts, since I am experimenting, and am not sure which work and that not.

this is the amplifier of the bass( on the input, will connect the output of the preamplifier)
 

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Hi Guido,
Yes, now you have it correctly shown. Was it a drawing error, or was it really wired like that?

I enjoy see different languages posted, I'm sorry it's twice the work to retype in English as well. I also understand that some things do not translate well. You have local sayings that do not make sense when put in English. But you have done a great job communicating.

-Chris
 
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