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  1. Audioguru

    Designing Circuit by BC546

    Your assignment says that "ro is infinite". Isn't ro your RL? Then remove your RL. I think you must learn about transistors because your resistor values appear to be selected at random. Here is the operation of your second transistor:
  2. Audioguru

    FM Receiver Circuit Help

    Your transistors are not biased properly so they will not work. I think you can make your circuit a "super regen radio" (many circuits are in Google). It basically detects (demodulates) AM but if it is tuned to one side of an FM station's frequency then it detects FM with "slope detection". Will...
  3. Audioguru

    NOT GATE Analog Circuit

    Your sketch shows a battery powering a light bulb and a switch that shorts the battery to make lots of smoke. Why? What do you want a NOT gate to do? It is simply a logic inverter, a high input produces a low output and a low input produces a high output. You can make an oscillator with two NOT...
  4. Audioguru

    Capacitor between collector and emitter help

    You forgot to post the schematic of whatever you are talking about. A capacitor between collector and emitter is used for positive feedback in a simple FM transmitter.
  5. Audioguru

    Use AC speakers in Car

    To produce 2W RMS into an 8 ohm speaker the voltage must be 4V RMS which is 11.3V peak-to-peak and the peak current must be 707mA. An amplifier with a single output can use a single 14.3V positive voltage and use power transistors to swing the output voltage up to +12.8V then swing it down to...
  6. Audioguru

    EMG amplifier circuit.

    Since U4 will amplify its own input offset voltage then a coupling capacitor on its output will block any DC. Use an attenuator to reduce the output voltage swing of U4. Then it can feed a DC voltage divider that produces half the maximum allowed DC input voltage of the Arduino.
  7. Audioguru

    EMG amplifier circuit.

    You are using opamps that have a maximum allowed supply voltage lower than your battery voltages. The opamps produce low output current so the 1k resistors R2, R3 and R13 you are using have values much too low. The coupling of the 1uF capacitor C6 into the 1k resistor R2 and the useless 1k...
  8. Audioguru

    Guitar 4x10 Cab wiring

    I think he wants to blow up his guitar pickup by connecting it to the output of the amplifier and maybe connecting the speakers to the amplifier input as microphones?
  9. Audioguru

    Guitar 4x10 Cab wiring

    I guess your amplifier uses obsolete vacuum tooobs so it has an output transformer with 4, 8 and 16 ohm taps? Why on earth does your amplifier have 8 ohm and 4 ohm INPUTS? 8 ohms and 4 ohms are speaker OUTPUTS. Why do you want to change the speakers wiring and count from 16 ohms to 8 ohms??
  10. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    I think that RV2 and RV3 should be mounted on the top or bottom if the board with very short wires or a new pcb should be used that has them included.
  11. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Your wires for RV2 are much too long and will act like antennas that might make the opamp pickup hum and other interference.
  12. Audioguru

    HELLO i have a problem with fm receiver

    I simulated the audio preamp Q5 and Q6 of the simple FM receiver but it did not work. I fixed the circuit and simulated it but my resistors, capacitors and transistor numbers are different.
  13. Audioguru

    1W audio power amplifier driven by electret ?

    Nobody is measuring the speaker output, instead we are talking about the amplifier power output.
  14. Audioguru

    HELLO i have a problem with fm receiver

    Q5 and Q6 are a 2 transistors preamp. Here is how Philips did it 50 years ago when I worked for them:
  15. Audioguru

    HELLO i have a problem with fm receiver

    Almost everything in that lousy circuit is an error. Yes. 1) If the output transistor was biased correctly (it is not) then its emitter will have about 2.5V on it and its current will be 2.5V/1.2k ohms= 2.1mA. Then its peak output current is 2.1mA. If you connect an 8 ohm speaker then its peak...
  16. Audioguru

    HELLO i have a problem with fm receiver

    Guess what? It drives a power amplifier, not a speaker. Then the power amplifier drives the speaker. The poor Engrish should have said it is an FM tuner, not an FM receiver.
  17. Audioguru

    HELLO i have a problem with fm receiver

    I do not think it is an awful "regenerative" circuit. Instead I think it is a simple "crystal radio" with an RF amplifier and an AM detector. When it is tuned to one side of an FM station then the AM detector will "slope detect" the FM and add lots of amplitude clicks and pops.
  18. Audioguru

    1W audio power amplifier driven by electret ?

    Why are you looking at cheap Chinese mini speakers that are 3 times larger than you want? Do you believe their lies about the output being 5W or 10W?
  19. Audioguru

    HELLO i have a problem with fm receiver

    The website with that "FM receiver" is full of errors and the author has very poor Engrish. It says it uses SEX transistors, not ordinary transistors. Maybe the arrow on each transistor says if it is male or female. The article says how to make the coils. Since it operates at high VHF...
  20. Audioguru

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Paul's schematic does not have RV3 so which schematic are you using? Your long green wire for C10 is different to what Paul did.
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