I built the tone control below. Should the 2n3904 bring the output back up that the tone part attenuated? Or do I need more.
An externally hosted image should be here but it was not working when we last tested it.
You could always add a common emitter output stage to drive your headphones.
It would be simple. Perhaps as simple as an NPN transistor with a resistor between the emitter and ground and an output capacitor to feed the headphones.
Of course, you'll need two of these circuits for stereo.
I just noticed that the schematic which you have provided does not include an output coupling capacitor. An output cap is absolutely necessary if you're driving headphones.
It would be simple. Perhaps as simple as an NPN transistor with a resistor between the emitter and ground and an output capacitor to feed the headphones.
Of course, you'll need two of these circuits for stereo.
I just noticed that the schematic which you have provided does not include an output coupling capacitor. An output cap is absolutely necessary if you're driving headphones.
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Your input stages seem to attenuate the signal, then amplify it again. This will add noise.
What is the purpose of this circuit? Much of the mixing could be done with purely passive circuits, with less cost, noise and distortion.
What is the purpose of this circuit? Much of the mixing could be done with purely passive circuits, with less cost, noise and distortion.
Passive is good.
First, I'm mixing three audio sources together. One mic, a Labtec computer type mic. Two, dual RCA summed together. Three, the dual analog output from a small DAC, which are also summed together. After mixing, it goes to the tone control, then on to the AGC, which can be bypassed. The final output goes into a single channel induction loop driver that has a mic level input. The loop driver isn't shown because it is a complete functional unit. I'm just mixing the three sources into it.
Thanks for your help.
First, I'm mixing three audio sources together. One mic, a Labtec computer type mic. Two, dual RCA summed together. Three, the dual analog output from a small DAC, which are also summed together. After mixing, it goes to the tone control, then on to the AGC, which can be bypassed. The final output goes into a single channel induction loop driver that has a mic level input. The loop driver isn't shown because it is a complete functional unit. I'm just mixing the three sources into it.
Thanks for your help.
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