Since the output of this chip can swing closer to the positive rail, the input bias voltage has been offset, to achieve equal swing, on both halves of the sine wave.

 

hi Paul,
Do you have a question about that amplifier circuit?
It is common practice to apply a DC offset to a OPA when using a Single power supply, what are the power supplies to this circuit?
E

 

hi Paul,
Do you have a question about that amplifier circuit?
It is common practice to apply a DC offset to a OPA when using a Single power supply, what are the power supplies to this circuit?
E

Is it okay to use my voltage divider, as part of my gain determining resistance ? Is it okay to use my voltage

hi Paul,
Do you have a question about that amplifier circuit?
It is common practice to apply a DC offset to a OPA when using a Single power supply, what are the power supplies to this circuit?
E

1 Is it okay to use my voltage divider as part of my gain determining resistance ? 2 Is it okay to use my voltage divider as ground potential, for my gain loop ?

 

See

 

You answered both of my questions, and I like what I see. Thank you.

 

Any special reason for doing it that way?
Conventional biasing will eliminate the 50K resistor.

 

In case there is any noise on the d.c. output of the a.c. to d.c. power supply, the noise is applied to both inputs. If you have equal amounts of noise at both inputs, there is no potential difference to be amplified.

 

Any special reason for doing it that way?
Conventional biasing will eliminate the 50K resistor.
View attachment 338141

See

 

Didn't see any of that on my breadboard.
What do the different color waveforms represent?

 

I did a parametric analysis using .Step param a 0.65 0.8 50m. The program made 4 calculations with different input signal amplitudes. The signal varied from 0.65V to 0.8V with a step of 50mV. I have shown that with equal resistors of 100K, there is an asymmetric limitation. And when using 100K and 120K resistors, the limitation is symmetrical.
This allows you to get a larger dynamic range of the input signal without limiting the output of the amplifier.
This is what Paul Bober wanted.

 

This is fantastic news to me, Paul Bober. Since 9.8 percent of my audio input signal is applied to the inverting input, does that change the input impedance of the non inverting input ?

 

This is fantastic news to me, Paul Bober. Since 9.8 percent of my audio input signal is applied to the inverting input, does that change the input impedance of the non inverting input ?

Rin=70kOhm

 

Thank you for letting me know.

 

I would like to thank everyone for their help. I have decided to go with this attached design.

 

I would like to thank everyone for their help. I have decided to go with this attached design.

Why such a low gain?

 

I only need the preamp to boost the guitar signal up to -10db, to feed into the RCA line level inputs found on home stereo equipment.

 

Sure and with a low gain and battery operation noise shouldn't be an issue.

 

Is this the schematic that you looked at ?

 

Hi Paul,
An important point is that you should always show the device power connections and the supply voltages on your circuit diagrams.
E

 

Is this the schematic that you looked at ?

Correct.