Within a few minutes of turn-on, and its performance remains solid over a large range of temperatures and power levels. These three factors, we believe, are the most significant ones that contribute to the excellent performance of LM3886/4870 amplifiers. Are there then any limitations to IC power amplifiers? The power handling capacity of a single IC is moderate. But this is not an inherent limitation. The power output can be increased significantly through the use of bridge and parallel techniques (See National Semiconductor's Application Note AN-1192). Understandably, some are concerned about thermal distortion, which arises from the heat generated in the output transistors flowing into the input transistors. The first generation IC op amps indeed suffered from this effect, but again, a significant progress has been made. By carefully controlling thermal gradients and by using the common-centroid layout for the input devices, the thermal distortion can be made negligible. If it is present, it would manifest itself as an increase in harmonic distortion at low frequencies. In Anedio's implementation, no increase is observed, and the total harmonic distortion at 20Hz remains below the threshold of measurement, about 0.0002%. In conclusion, IC power amplifiers, such as the LM3886/4870, can be pushed to state-of-the-art performance by carefully optimizing the circuitry around it and the PCB layout. And such a level of performance can be achieved at a fraction of the cost of typical high-end amplifiers, making them accessible to all audiophiles. Most important of all, it offers exceptionally musical sound that engages the listener, powerful transients that communicate the emotional impact, and extraordinary definition that draws the listener closer to live performance.