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  1. Audioguru

    Back to the Breadboard

    Good, it works. Does the gain control adjust the amount of distortion to an amount that you want?
  2. Audioguru

    Back to the Breadboard

    Did you replace the 220k resistor between pin 1 and pin 2 with a gain pot? No reading on pin 1 means 0V? If pin 1 is 0V then pin 2 should also be 0V.
  3. Audioguru

    Back to the Breadboard

    It sounds good and I am surprised about the sustain at the end of your playing. I guess the compression caused by the diodes allow the high gain of the opamp to produce sustain.
  4. Audioguru

    Back to the Breadboard

    270k is 1000 times more than the correct 270 ohms.
  5. Audioguru

    Back to the Breadboard

    Congratulations, the voltages are correct and now it works well. I am glad you did not attach a photo of the breadboard because the mess of wires all over the place on a breadboard makes me laugh for hours until it hurts.
  6. Audioguru

    Back to the Breadboard

    This is a "pedal" circuit. While playing the guitar he pushes the pedal (stomp box) with his foot to activate it. Most pedals are used near the guitar and are powered from a single 9V battery.
  7. Audioguru

    Back to the Breadboard

    An opamp will not work if you short its sounds input at pin 3 with a power supply. Why Use a 4.5V power supply when a voltage divider is simply two identical value resistors in series and a filter capacitor to ground? The 4.5V is fed to pin 3 with a 1Meg resistor and the audio is...
  8. Audioguru

    6v Battery Pack

    I have used Ni-MH batteries for years since about 25 years ago all my Ni-Cad cells were shorted. Does your battery also have old and shorted cells?
  9. Audioguru

    Distortion Pedal Redux

    Pantera, Cemetery Gates has too much high frequency shrill noise for me because my PC plays hifi pretty well so it does not have a treble tone control for me to turn down. It sounds much better with my hearing aids removed because I have normal-for-my-age (75) high frequency hearing loss and the...
  10. Audioguru

    Distortion Pedal Redux

    Yes, I cutoff the useless 10k resistor. I also notice than the 1k resistor and 0.22uF capacitor cut most mid and high audio frequencies at and above 727Hz. BAD!
  11. Audioguru

    Distortion Pedal Redux

    The TS-808 circuit has input and output transistors added and a multivibrator that flutters the audio back and forth between the clean and the distorted signals. The distortion circuits are exactly the same.
  12. Audioguru

    Distortion Pedal Redux

    Venom, you do not understand that the circuit in this thread does apply Vref to the non-inverting input, through the 1M bias resistor. Then the input transistor in the ES-808 circuit you posted is not needed. The failures and mediocre results were caused by wiring errors, not by the circuit.
  13. Audioguru

    Distortion Pedal Redux

    The distortion opamp on the TS 808 has exactly the same diodes soft-clipping circuit as in this thread except it uses a very low value 10k resistor to bias it, then it needs the transistor emitter-follower at the input to increase the input resistance up to almost the 1M resistor here. The...
  14. Audioguru

    Distortion Pedal Redux

    Venom, you show a circuit with many parts that are not needed. The opamp being used here has the correct voltages but the unused opamp has the wrong voltage and I do not know why. You show a modern and expensive LT1056 opamp in a simulation that has no DC input offset voltage and no input...
  15. Audioguru

    Distortion Pedal Redux

    The diodes, 220k resistor and 100pF capacitor all connect between the same places (pin 1 and pin 2) so the sequence of them does not matter. The crackling, spike and lasting for half a second is probably caused by the input 470nF capacitor value is way too high. The 470nF is half a microfarad...
  16. Audioguru

    Distortion Pedal Redux

    I re-drew the schematic showing pin numbers for a dual opamp. Many of your voltages are completely wrong. Instead of the gain pot you should have the 220k resistor and the 100pF capacitor between pin 1 and pin 2. If the resistor or a piece of wire is missing then the voltages on pin 1 and pin 2...
  17. Audioguru

    Distortion Pedal Redux

    Pin 1 and pin 2 on which opamp? A single opamp or a dual opamp? If you are using the 4558 dial opamp then you need a schematic that uses it.
  18. Audioguru

    Distortion Pedal Redux

    Changing the 470nF capacitor to a 1nF one will change the tone of the sounds. You might like it or maybe a value in between.
  19. Audioguru

    Distortion Pedal Redux

    R32, R33 and C30 all connect together and make the filtered "half the supply voltage". Connect the + input of the unused opamp there. The 1Meg resistor R43 connects to + input of the used opamp. I think I mentioned before that the value of C23 (the input capacitor) is way too high at 470nF...
  20. Audioguru

    Distortion Pedal Redux

    R32 and R33 are the voltage divider that make the filtered 4.5V. The 1M resistor feeds the 4.5V through the 1M resistor to the + input of the opamp that is used. The 1M is the same as the 1M of the input of a vacuum tubes amplifier. A guitar pickup is made to feed 1M or more. The input...
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