In recent years a significant number of CFLs on the market (not from famous brands!) had such poor EMI countermeasures that all the DAB radios in people’s houses ceased working altogether. Also, a recent report also indicated that up to 30% of recent LED bulbs fail the EMI standard.
Our tests show that switching on a single approved CFL will have a detrimental effect in an otherwise EMI quiet house which has been electrically ‘tuned’ for better sound from the installed high quality stereo system, and as the number of CFL and LED bulbs is increased, so is the loss in sound quality.
Since the EU is outlawing relatively EMI quiet incandescent lighting on grounds of inefficiency, audiophiles should be stocking up with supplies of old bulbs whilst they can. The more efficient 12V quartz are fine for noise providing they are transformer driven and not powered by those cheap plastic solid state switchers which are very radio noisy. There will be no loss to the environment since audiophiles tend to listen under dim lighting!