Being an audio enthusiast, a proper power amp can be a thing of beauty. Big toroidal transformers, capacitor banks and relatively easy to understand symmetrical layout. A friend of mine donated his NAD 214 after upgrading to a 200 watt, THX certified, Parasound poweramp.
The NAD wasn’t without fault. It sporadically started producing some noise and hiss. A bit of googling showed some common issues with the 214 (and his bigger brother, the 216). Issues that could be the cause of the noise:
- Bad solder joints
- Oxidized print connectors
- Fried speaker relay
- Undersized/ dried up main PSU capacitors
- Offset idle current