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  1. Audioguru

    routing 2 channel audio to 5.1 speaker system

    An audio mixer circuit uses an inverting opamp so that the inputs are separated from each other. Two resistors also are a mixer but they reduce separation if the input signals have any series resistance. The audio amplifier/speakers in this thread might be a little portable with the speakers so...
  2. Audioguru

    routing 2 channel audio to 5.1 speaker system

    Some TVs have an electrically "alive" common because they are missing a power transformer, then they do not have outputs. Connecting anything to the internal low impedance speaker wires can cause electrocution. If a TV has stereo aux outputs then since many Noobs short them together for mono...
  3. Audioguru

    Just When I Thought it was Going to Be Easy

    Fuzz is severe distortion for people with good hearing. For people whose hearing of high frequencies is destroyed by age or deafened by very loud rock "music" then the fuzz is muffled and is simply a different kind of tone. The tone control in this distortion pedal circuit adjusts the amount of...
  4. Audioguru

    routing 2 channel audio to 5.1 speaker system

    He has a stereo system. A mixer as simple as two resistors reduces the channels separation. There are tweeters and a woofer. Where is the crossover network?
  5. Audioguru

    Just When I Thought it was Going to Be Easy

    Sayal was a liquidator. They have never been a real electronic parts distributor like Digikey or Newark. Sayal bought unused genuine surplus electronic parts and items from companies then sold them cheaply. Now that there is ebay and AliExpress who sell very cheap fake or defective parts, maybe...
  6. Audioguru

    routing 2 channel audio to 5.1 speaker system

    Ebay and you mentioned a very expensive AD827 opamp that works as high as 50MHz. Audio goes only to 20kHz so why pay a lot for video and radio frequencies when a much less expensive audio opamp is available. A fake ebay opamp can be VERY cheap.
  7. Audioguru

    Just When I Thought it was Going to Be Easy

    He doesn't need a buffer opamp. Some guitar pedal circuits use a dual 4558 opamp because it is an "improved" old 741 opamp (and is stereo). In Google, the same circuit as in this thread has a dual TL082 opamp with only one of the opamps used.
  8. Audioguru

    Just When I Thought it was Going to Be Easy

    Amazon and ebay sellers probably get fakes and defective parts from the garbage bins of real manufacturers. SparkyCal, All or some of your opamps are marked wrong. Then you cannot be certain of what specs they have or even know if they are electrically defective. I order parts online from...
  9. Audioguru

    Just When I Thought it was Going to Be Easy

    Amazon sell shoes and clothes. Then Amazon and their sellers know nothing about the electronic parts they sell except the color and weight. EDIT: An IC marked TL081 that behaves like a TL082 is obviously a fake.
  10. Audioguru

    LED chips and smoking

    Maybe a fault in the circuit current-limiting burnt the original LED but the fault is still there and caused the replacement LED to also burn.
  11. Audioguru

    routing 2 channel audio to 5.1 speaker system

    The appearance and extremely low price of the ebay very high frequency AD827 dual opamp smells like a fake. Ebay sells one at $1.02US. Digikey sells one at $27.80US. Mouser sells one at $26.48US. Why buy a fake very high frequency opamp made for video (and what will you get at that extremely low...
  12. Audioguru

    Power and Control PC fans with Cigarette Lighter

    Will the battery in the van survive being discharged all night by a fan? The next morning maybe the van engine will not start.
  13. Audioguru

    routing 2 channel audio to 5.1 speaker system

    We NEVER use a diode to feed audio. It produces EXTREME distortion. Diodes can mix DC voltages but audio is AC voltages. You need an audio mixer product that has a frequencies crossover circuit that feeds high frequencies to the little satellite speaker amplifiers and feeds only the deep low...
  14. Audioguru

    555 timer output set to 200hz is not what i was expecting to see?

    Tony, did you notice that the value of your resistors are 1400 times too small and the value of your capacitor is 1400 times too large?
  15. Audioguru

    Just When I Thought it was Going to Be Easy

    Input pin 2 is supposed to have the same voltage as the output pin 6 which feeds the voltage to it through the gain pot. Maybe the gain pot is missing a connection?
  16. Audioguru

    School Project: Off-the-shelf EQ module board

    Without having a ground then one of the power supply voltages probably far exceeded the rated 15V and caused a problem. I think it stopped working when one or more opamps got too hot with the over-voltage.
  17. Audioguru

    Back to the Breadboard

    The datasheet for the 3-terminals jack should show a photo explaining which terminal is the switching one.
  18. Audioguru

    Lithium ion Battery

    Most 3.7V lithium batteries have only 2 wires but your battery has 3 wires. Temperature sensor to prevent an explosion? Lithium batteries are made in many different shapes and sizes. Therefore buy an original battery as a replacement.
  19. Audioguru

    Back to the Breadboard

    A 4.7k resistor in series with a 3.2V blue LED and powered from 9V draws (9V - 3.2V)/4700 ohms= 1.2mA for a fairly dim LED. Use 470 ohms or 270 ohms to be much brighter. A good LED is bright over a wide angle. A cheap old LED from the other side of the world is dim but has a case that focuses...
  20. Audioguru

    Back to the Breadboard

    1uF is 1000nF and the output capacitor does not need to be that much. A 1uF film capacitor is fairly large and is expensive and a 1uF electrolytic capacitor is even larger but a 330nf film capacitor is small and inexpensive. Use a 1uF electrolytic if you want, it will sound the same. I forgot...
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