hello,

i am trying to make an oscillator that I can plug into a guitar amp
(or keyboard or bass amp). i made an oscillator, but the amplitude of
the signal is way too big, 9 volts, i was wondering how i could bring
this signal down to the millivolts level (i think that's typical for
keyboard amps)..... could i just stick a resistor at the end of my
output.... for some reason I feel weird about doing that.... like
thinking that maybe I need a buffer in there, that if I do just put a
resistor at the output of my oscillator that that when i do hook the
circuit up to a load (the guitar amp) that it would change the
signal.... like it wouldn't be consistent but instead dependent on the
load..... could anybody help me out with this?

thanks
joshua

On Fri, 10 Aug 2007 15:48:59 -0700, panfilero wrote:

> hello,
>
> i am trying to make an oscillator that I can plug into a guitar amp
> (or keyboard or bass amp). i made an oscillator, but the amplitude of
> the signal is way too big, 9 volts, i was wondering how i could bring
> this signal down to the millivolts level (i think that's typical for
> keyboard amps)..... could i just stick a resistor at the end of my
> output.... for some reason I feel weird about doing that.... like
> thinking that maybe I need a buffer in there, that if I do just put a
> resistor at the output of my oscillator that that when i do hook the
> circuit up to a load (the guitar amp) that it would change the
> signal.... like it wouldn't be consistent but instead dependent on the
> load..... could anybody help me out with this?

http://www.google.com/search?q=voltage-divider

Have Fun!
Rich

panfilero wrote:

> hello,
>
> i am trying to make an oscillator that I can plug into a guitar amp
> (or keyboard or bass amp). i made an oscillator, but the amplitude of
> the signal is way too big, 9 volts, i was wondering how i could bring
> this signal down to the millivolts level (i think that's typical for
> keyboard amps)..... could i just stick a resistor at the end of my
> output.... for some reason I feel weird about doing that.... like
> thinking that maybe I need a buffer in there, that if I do just put a
> resistor at the output of my oscillator that that when i do hook the
> circuit up to a load (the guitar amp) that it would change the
> signal.... like it wouldn't be consistent but instead dependent on the
> load..... could anybody help me out with this?

You need a resistor like the one you mention AND another resistor to ground.
This makes a 'voltage divider' that attenuates the signal.

To attenuate from volts to millivolts you need a ratio of 1000:1.

I suggest you connect a 47k resistor to the oscillator output. Connect the end
of that to a 47 ohm resistor and connect the other end of the 47 ohm resistor to
ground. Take the signal from the junction of the two resistors.

Graham

To

panfilero panfilero@gmail.com posted to sci.electronics.design:

> hello,
>
> i am trying to make an oscillator that I can plug into a guitar
> amp
> (or keyboard or bass amp). i made an oscillator, but the
> amplitude of the signal is way too big, 9 volts, i was wondering
> how i could bring this signal down to the millivolts level (i
> think that's typical for keyboard amps)..... could i just stick a
> resistor at the end of my
> output.... for some reason I feel weird about doing that.... like
> thinking that maybe I need a buffer in there, that if I do just
> put a resistor at the output of my oscillator that that when i do
> hook the circuit up to a load (the guitar amp) that it would
> change the signal.... like it wouldn't be consistent but instead
> dependent on the load..... could anybody help me out with this?
>
> thanks
> joshua

A resistor based divider is appropriate.