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  1. Audioguru

    Basic Soldering advice

    My Weller soldering iron has controlled temperature so it does not incinerate the rosin in solder making smoke, it just heats the rosin making a pleasant smell. I wonder if a cheap soldering iron without temperature control will cause a fire?
  2. Audioguru

    Audio amplifier compatability...

    We talk in detail here. What is "a simple circuit mic"? All mics have a name and all have almost the same low level. The most common mic today is called "electret condenser" and it does not work without power. An older mic is called "dynamic" and it is like a little speaker with a magnet and a...
  3. Audioguru

    Basic Soldering advice

    I never smoked rosin solder and I never ate brownies made from solder. I have not seen Mary Wana for many years but I smell it frequently in parking lots. My favourite solder is also Ersin multi-core.
  4. Audioguru

    Electric Guitar Amp Circuit Check

    If you add an amplifier and 9V battery to the passive guitar then what will it drive? If it drives a speaker then use an LM386 amplifier. It will have a fairly low output sound because a 9V battery can power an amplifier that produces an output of only about 0.45 Watts when the battery is new. A...
  5. Audioguru

    Best Amplifier Type

    Most high power audio amplifiers use power transistors in a class-AB circuit. A few high power class-D amplifiers are good. Most high power radio frequency amplifiers use old vacuum tubes. There are some power transistors made for fairly high voltages.
  6. Audioguru

    Epicure Products

    My wife sells Epicure food spices, Avon cosmetics and a few other things. I never seen Epicure speakers but Google says the EPI-100 was like a copy of the pair of Acoustic Research AR4x that I bought in about 1964. Its sealed enclosure allows the 8" woofer to sound tight down to about 60Hz then...
  7. Audioguru

    On/off switch for a quadcopter?

    My latest Syma quadcopter has a removable battery and its on-off switch is so small it is hard to see. The switch looks like it is part of the battery connector that is on the quadcopter, not on the battery.
  8. Audioguru

    Thyristor dimmer lamp buzzes

    I think you bought a poor quality cheapo light bulb made "over there" instead of a high quality one made locally.
  9. Audioguru

    Audio amplifier compatability...

    It looks like you have not looked at the datasheet for the PAM8610 IC used in the Chinese amplifier. It shows that its minimum supply is 7V (that a 9V battery will quickly drop below) and its output to an 8 ohm speaker is only 2W at low distortion. A little 9V alkaline battery is designed to...
  10. Audioguru

    Electric Guitar Amp Circuit Check

    Having way too much gain produces "fuzz" that is distortion trash. But the low impedance of the amplifier input and the horrible speaker muffles the fuzz and just makes awful sounds.
  11. Audioguru

    LEDS in parallel circuit help

    The LEDs you have are not ordinary LEDs as shown by Sundy. They operate the built-in circuit from typically 4.5V or 5V max. They say if the power supply is more than 5V then a series current-limiting resistor is needed to limit the current to 20mA.
  12. Audioguru

    Audio amplifier compatability...

    The Chinese seller lies about the output power of the amplifier. The datasheet for the PAM8610 IC shows 5W into 8 ohms with low distortion, 8W with considerable distortion and 10W with severe clipping distortion when its supply is 12V.
  13. Audioguru

    repair parts

    I guess that Digikey does not stock some Chinese or Japanese repair parts. Recently my projects ran out of 2N3904 transistors so I raided some old circuit boards for many 2SC945 transistors (different pin-out that the 2N transistors). Digikey does not stock 2SC945 transistors.
  14. Audioguru

    Basic Soldering advice

    I have used 63/37 tin/lead with flux core solder for most of my life and it worked extremely well, solidifying immediately. Recently I used up my 63/37 and began using some 60/40 flux-core "electronic" solder I had. It makes terrible joints unless I hold the joint still while it cools. Hee...
  15. Audioguru

    Electric Guitar Amp Circuit Check

    What is a "passive" electric guitar pickup? A passive guitar is an acoustical guitar without a pickup. An electric guitar doe not have an amplifier built into it, the two are connected with a cord.
  16. Audioguru

    repair parts

    I would download the service manual and see the parts list in it. Then I would test the parts and order replacement parts from Digikey. But you do not say what country you are in and maybe Digikey does not ship things there.
  17. Audioguru

    What is the real name of this part?

    The severe distortion looks normal for a vacuum tube geetar amplifier. A transistor with no negative feedback also produces severe distortion like that.
  18. Audioguru

    Electric Guitar Amp Circuit Check

    When played normally, a magnetic pickup on a guitar produces a pretty high signal level when the preamp has a very high input impedance. The high impedance also allows the magnetic coil to resonate with the capacitance of the connecting cable producing a peak in the frequency response at around...
  19. Audioguru

    Car Battery

    Absolutely NOT! That is the cells in parallel making a 2V battery. The cells are in series making a 12V battery like you described before.
  20. Audioguru

    If I have a Li-Po battery connected to four quadricopter motors...

    What does your hovercraft do when you power its motors with the battery? Does it "hover"?
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