Anyone have a simple schematic that can convert a single ended audio signal into a differential signal, but only using a single supply voltage (12V)?
Thanks.
Thanks.
Single supply is no problem, other than reducing the maximum signal output level.
See figure 3A here: https://sound-au.com/project87.htm
Use input and output 10uF capacitors, and bias the positive op amp inputs at +6V through 10k resistors.
Also use a decoupling capacitor between the +/- op amp supply pins.
See figure 3A here: https://sound-au.com/project87.htm
Use input and output 10uF capacitors, and bias the positive op amp inputs at +6V through 10k resistors.
Also use a decoupling capacitor between the +/- op amp supply pins.
A extremely professional way to do this would be like so (Courtesy : Analog Devices Inc.) The gain, as always, is given as |Rf/Ri|, controlled using only one resistor.
To operate the above circuit from a single power supply,
1) Do not use a coupling capacitor to block the standing DC from the input signal.
2) Apply a voltage equal to this DC to pin 5 (non-inverting input of bottom opamp), in place of the 75R resistor.
1) Do not use a coupling capacitor to block the standing DC from the input signal.
2) Apply a voltage equal to this DC to pin 5 (non-inverting input of bottom opamp), in place of the 75R resistor.
It assumes that the input already has some DC on it and yes, direct copy / paste may not work ...
Thanks. Any issue replacing the 2x100k resistors with 20k ones? Looks like the cutoff is still low, and would prefer to keep lower values if I can. I can simulate it too, all good. But just curious your thoughts. Thanks.
The 100k parts are just to keep the coupling capacitors charged to +6VDC, and their exact values are not critical,
other than their contributions to low frequency roll off. With 10uF capacitors, the total output loading should be >10k each.
other than their contributions to low frequency roll off. With 10uF capacitors, the total output loading should be >10k each.
I’ve been putting together a custom plate amp using TPA3255 (along with an entire 2.1 amplifier with active crossovers I’ve been building). The tps3255 needs differential inputs but I only have a single ended subwoofer output. I understand how to convert wifi two supplies, but using opamps with one supply always trips me up. So thanks for that.
Thank you for sharing this schematic. It's working really nice for me. I had a bit of trouble trying to make it work in either tina-ti and Kicad spice simulation, but with a bit of fiddling, it worked.
For anyone who may need, a bandpass can be adapted by adding a series resistor next to the capacitor connected to the input, and a capacitor connected to ground after that