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Electric Guitar Amp Circuit Check

Discussion in 'General Electronics Discussion' started by tedstruk, Jan 31, 2017.

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  1. tedstruk

    tedstruk

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    Jan 7, 2012
    Will this work as an amp for a electric simple guitar?
     

    Attached Files:

  2. AnalogKid

    AnalogKid

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    It is *very* difficult to say from your schematic, but almost certainly not. A single transistor does not have enough gain to bring a guitar pickup all the way up to speaker level. Please supply more information about the transistor (part number - ?????), speaker (size, impedance), and a drawing with all of the connections shown in an unambiguous manner.

    What is your experience level and skill set for constructing this circuit?

    ak
     
  3. tedstruk

    tedstruk

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    Jan 7, 2012
    old man, smarter than you, using an epitaxial transistor and a set of 10v 100uf caps, and a couple of resistors I found in my junk box...
    mostly trying to figure out what I did the first time to make an amp work!
    The first one I made, didn't amp much, only a few miliamps, so I added something to it, can't remember what I added to the circuit, but it made almost 6 miliamps out of .002, so I was happy!
    what would be my best option at this point?
     
  4. AnalogKid

    AnalogKid

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    Jun 10, 2015
    Add something more to it.
     
    Harald Kapp likes this.
  5. tedstruk

    tedstruk

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    OK, when you add volts you are changing the system. I know that much. I am using a 9v battery to power an amplifier that is not supposed to change the system in-outs, so I will need some kind of power management system to handle the 9v with. Lets say a regulator that matches the volts of the in-outs from the instrument amp...
    does anyone know the volts of the ins in a standard stage audio amplifier?
    Then I think I should want a pre amp, not an amp in the instrument, which shouldn't even need one if the ohms are right? Why not just forget the amp, and hock it up straight through? is my circuit right without the amplifier?
     
  6. tedstruk

    tedstruk

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    Jan 7, 2012
    What would be a good regulator circuit for 9v, so that it does not effect the in-out?
     
  7. Harald Kapp

    Harald Kapp Moderator Moderator

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    I can't answer for your age but I doubt the second part of that assertion.

    This is a very unphysical statement which means really nothing.
    An amplifier is a device that takes a signal at its input (this signal can be a voltage or a current or both), amplifies this isgnal by a certain factor (gain) and outputs another signal (again voltage or a current or both). The gain is set by the circuit and its parameters. Gain can be made more or less fixed over a wide range of supply voltages. An amplifier designed for 9 V supply voltage will not necessarily have less gain at 8 V or more gain at 10 V. Specifics depend on circuit details.

    Please use standard notation for drawing circuit diagrams. It is very hard to follow a diagram of the kind you supplied. Standards are there for a purpose. These instructions on how to read a schematic are also helpful in the reverse direction: drawing a schematic.
    It is also customary to label the parts used directly within the diagram, not on a side note.

    To the best of my limited knowledge that's about 0.2V...1V. It very much depends on the make of the amplifier and the amount of distortion you are willing to accept in case the amplifier is overdriven (forced into clipping the signal).
    You also have to consider the interplay between the output impedance of your source (e.g. guitar pickup) and the input impedance of the amplifier: amplifier is a load to the source. The lower the input impedance of the amplifier, the lower the output voltage of the source and vice versa.
     
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  8. AnalogKid

    AnalogKid

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    I agree with Harold.

    ak
     
    Last edited: Jan 31, 2017
    BobK and davenn like this.
  9. AnalogKid

    AnalogKid

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    No, you're not.

    a) An electrical pickup device for a guitar was patented in the 1930's. That's older than you. The innergoogle is awash in circuits, projects, kits, patents, tutorials, how-to videos, and theory lectures covering every possible aspect of this field of devices.

    b) And yet here you are, asking me.

    ak
     
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  10. tedstruk

    tedstruk

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    Alright, I understand, there are ways that you do stuff and ways that you don't do stuff. Asking you was one of those don't do stuffs, and not using etiquette and protcol was also a don't do stuffs, and so I missed two of three on those....

    I like those kit amps, they are fun to use, yeah I found these plans for a lap steel guitar, and I have a nice little peavy bass transducer that should perform nominally with it. I am not building a slap together guitar though, so I want the circuits to be right. I wil try again and using some ettiquette and protocol, and few of the other hackers in here 'kid' I will attempt to create a great professional lap slide steel guitar. With the ohmage of my humbucking dual coil being 5.8, I wonder if I should even consider an amping factor, it seems that without the right ohmage, it wouldn't even work, but I think this is about passive vs active, and I think this is a passive transducer pickup coil, WILL THAT EFFECT THE TYPE OF AMP I MIGHT USE?
     
  11. Audioguru

    Audioguru

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    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 5kHz to produce the "twang" sound that an ordinary guitar speaker has trouble producing without the peak..
     

    Attached Files:

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  12. Harald Kapp

    Harald Kapp Moderator Moderator

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    Sorry, wrong. Asking others is the essence of fora like this one. And I do think we can be proud of having a rather broad-minded community where a lot of aspects concerning electronics can be covered.

    Right, and I'm glad you recognize this. We don't want to disencourage any member of this forum. However, participation is voluntary, the only compensation being the satisfaction of being able to help (sometimes more, sometimes less, alas). Getting some respect is the least we expect.

    @Audioguru has given you some good information.
     
  13. AnalogKid

    AnalogKid

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    Jun 10, 2015
    AG -

    I was working on an explanation of how the input impedance of a preamp affects not only the signal level but also the frequency response of the pickup. LOVE the freq chart.

    ak
     
  14. tedstruk

    tedstruk

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    Jan 7, 2012
    Wow thanks audiogu.... but the sytem is still the system ain't it? I mean dropping a 9v battery into a passive driver just ain't much of a good idea?
    The point being that I knew what kind of guitar this pickup came out of, but only accidentally found that this particular pickup is passive, which I found at a Garage sale for .25. I don't know exactly why I want to put an amp in it, just thought if I was going to all the work to build one, that it would be nice to make it portable...
    I will go find a chart of symbols and see if I can make the circuit more clear... thanks for the great arduino speak,
     
  15. Audioguru

    Audioguru

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    Sep 24, 2016
    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. garublador

    garublador

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    Oct 14, 2014
    Most guitar pickups are considered passive because they do not require an external voltage source to work. "Active" pickups have a way fewer windings and a preamp built in that runs off a 9V battery in the guitar. It's the need for an external voltage source that makes them "active."

    http://www.dawsons.co.uk/blog/what-is-the-difference-between-active-and-passive-pickups

    It sounds like the OP is trying to make this cheap passive pickup into an active pickup. My guess is it will sound pretty terrible, but it's an interesting project from a learning electronics standpoint.
     
  17. Audioguru

    Audioguru

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    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.
     
  18. tedstruk

    tedstruk

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    Jan 7, 2012
    Passive - requiring outside influence to operate
    Active - having its own power source
    ie.(as in)
    This particular transducer came out of a guitar that had no internal battery, and got all of its power from the input to it.
    eg.(as was)
    A guitar that has a 9v battery in it has active circuitry.
     
  19. Audioguru

    Audioguru

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    Sep 24, 2016
    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 cheap clock radio is louder.
     
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