Amplifier noise caused by bad hybrid bricks?
There can be all sorts of sources for low level noise or static including bad connections almost anywhere, defective semiconductors, and erratic power amp modules. These are usually hybrid circuits – multiple devices mounted on a common substrate and interconnected via a variety of technologies. Think of them as entire subsystems encased in plastic. Thus, hybrid bricks may have problems with noise especially considering that they may run hot and be abused by poor tastes in music (or at least high volume levels). Thermal cycling can take its toll on this kind of device. If you have eliminated other likely causes, replacing the brick would be the next step if the module is not that expensive – how much do you value your time and hair? Of course, if there are separate bricks for each channel, one channel is most affected, and the volume control does not affect the level of the noise, the choice is clear – swap. This will be relatively low risk in most cases. A hot air gun used carefully o
