Hello EEVblog community! I am VERY new to electronics and circuits and am motivated to understand developing synthesizers.
I have followed many tutorials that i could find, and followed several diagrams but am quite lost on my own.
I have this Dual Op Amp "NJM2068D" that I am trying to use as a basic audio amplifier for an incoming signal (1/4" TS).
Operating Voltage ±4V~±18V schematics on NJM3068DD PIN FUNCTION
1.A OUTPUT
2.A –INPUT
3.A +INPUT
4.V5.B +INPUT
6.B –INPUT
7.B OUTPUT
8.V
I just learned about negative voltage in circuitry for the first time, and the concept of virtual ground--but have questions...
Since I am using an Arduino Uno to develop my project, would I lead my V- to GND on the board? Would my virtual ground (the point which i ground to the rest of my circuit?) be the point between the voltage divider?
If this is true, when I have other devices on the circuit that use the same V+ rail (a OLED display for example), if I wanted them to use "max voltage" before I divided by two, I would connect 'from V+ to V-' rather than 'from V+ to Virtual ground', correct?
After trying multiple generic OpAmps on Kicad and eventually downloading a SPICE model that worked (...why is this such an issue?) Running my circuit in a Kicad Spice simulation seems to work well as I am getting the correct voltages at all nodes...(why doesnt generic opamp work for me? would not amplify, simply passed signal. Also could NOT get any 555 timers to work in simulation...)
So without removing the OpAmp from the board I am salvaging it from, I am trying to use it as is.
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I am guessing that the Pink wire is V- while Red is V+? I hear nothing when wiring, and I assume its due to insufficient voltage, seeing as I would max at ±2.5V
(not really sure what to do with the Yellow (A+ IN) either).
How do I power my OpAmp (requires ±4V, so I need 9v) while still using my Arduino? I have a 12v DC power supply and the jack that fits it from another board, how can I incorporate that?
The red and blue dashed wires are the 1/4" TRS and the white and green dashed wires head to a variable potentiometer which control the volume.
With all the capacitors and resistors, do you think that the power rail splitting is already done for me on this board? I believe it was likely done on the mother board this connected to via ribbon but am very unsure....
Without a voltage meter or oscilloscope, I am taking shots in the dark. I am really fascinated with everything I am learning quickly, but feel I would benefit hanging around a few gurus.
Thank you for your time and i apologize for a million questions!