I'm trying to drive a TPA6120 headphone amplifier with TL072. I use single 24VDC supply with a TLE2426 virtual ground.
The TL072 works well and puts out around 21Vp-p sine wave. But as soon as I connect the TPA6120 amplifier to its output the sine gets clipped to around 17-18Vp-p. That is 6V less than supply voltage. Any idea wahat could cause this? Looking at TL072 datasheet Figure 6-12 and 6-13, output swing with 1k load (12mA@+-10V) should still be atleast 22V.
- The sine looks ok from first TL072 output.(Yellow line on scope screen)
- The sine comes out clipped from second stage(Blue line on scope screen)
- The signal then enters TPA6120 which is loaded with 16 ohm resistor at its output.