Re: Audio Blending Between Opamps?

On Thu, 15 May 2008 19:50:20 -0700 (PDT), Brandon
<bcr07548@xxxxxxxxxxxxx> wrote:

In a little audio project I am working on, I am using two
opamps (one dual opamp actually) as buffers for incoming audio
signals. I want to blend the output of the two opamps using a 100K
pot and then "feed" that blended signal into a third opamp.

** It is not at all clear what you mean by blend with a 100K pot.

What is the function of the pot ????

Well, at a high level, I basically just want to be able to crossfade
two audio sources (we'll call them A and B) so that as A becomes
"louder," B becomes "softer." I was under the impression that could
easily be accomplished with a pot. In this case, input A (coming
directly from the output pin of an opamp) would be connected to the
1st lug of the pot, input B (coming from the output of another opamp)
would be connected to the 3rd lug, and the shared 2nd lug would be
connected directly to the input of a third opamp which would act as a
buffer and send the crossfaded signal on its way. Since you
questioned it, is there any reason why that sort of setup wouldn't
accomplish what I want? Or did I just not explain the scenario well
enough up front?

I think that is basically what the crossfader is a DJ mixer is - a
dual gang (for stereo) slider-style potentiometer. Assuming that
approach would work, what I was really asking about was whether there
are any complications I hadn't thought about. I don't think I should
need any pull down resistors or anything of the sort.

-Brandon

I suppose that it is the way it was done in pro equipment for decades
might ease your mind. The modern way is digital, but that has a
higher startup cost.

.

Relevant Pages

  • Re: Audio Blending Between Opamps?
    ... signals. ... pot and then "feed" that blended signal into a third opamp. ... ** It is not at all clear what you mean by blend with a 100K pot. ...
    (sci.electronics.design)
  • Re: Audio Blending Between Opamps?
    ... signals. ... pot and then "feed" that blended signal into a third opamp. ... ** It is not at all clear what you mean by blend with a 100K pot. ... Well, at a high level, I basically just want to be able to crossfade ...
    (sci.electronics.design)
  • Re: Audio Blending Between Opamps?
    ... > pot and then "feed" that blended signal into a third opamp. ... > any different because the signals come together in a Y and there are ... Connect one end of the 100K pot to one output of the dual opamp, ... It will work better if you add a ~100K fixed resistor ...
    (sci.electronics.design)
  • Re: Alternative voltage reference?
    ... using an opamp voltage follower. ... What's the voltage reference for? ... Again, no precision. ... the pot, which means you can at least trap your 0.5V in there with a ...
    (sci.electronics.basics)
  • Re: Alternative voltage reference?
    ... What's the voltage reference for? ... Again, no precision. ... the pot, which means you can at least trap your 0.5V in there with a ... you can keep the opamp and use the ...
    (sci.electronics.basics)
Quantcast