I still question the use of descrete componets vers an op amp preamplifyer circuit (link at begining of this thread somewhere
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link to schematic using transistors for preamp, op amps for bandpass filter and an lm386 for amp
**broken link removed**
what I am after is a per amp followed by perhaps a bandpass filter to limit the static then an amp that can input into a set of headphones AND a switch to turn on an amp say 7-10 watts so several cubscouts can hear at one time.
Re: Transistor Preamp.....And What do you Think makes up an Integrated Circuit?
It May be Smaller, But its still comprised of Transistors.
A Band Pass Filter Won't Remove STATIC.
It will Only help Narrow the Bandwidth to help picking up certain Frequencies better.
Such as a Higher Frequency to Hear a Bird, while Limiting Lower Frequency sounds, like a car going by.
Reguardless of What Power Amp, your using,
To Eliminate HISS from the Amp into Headphones, You need to put a Resistor in Series with your HeadPhones. Usually a 1/4 watt resistor, with a Value of Between 47 and 100 Ohms is Good.
And with 9 volt supply, an LM386 can Easily Drive 10 sets of Headphones.
Use a Seperate Resistor to EACH Headset.
7 to 10 Watts is really an Overkill for Head Phones.
And if you use it to drive a Speaker, you will just wind up with Lots of Feedback SQEELING