What is the life expectancy of the valves in my TL Audio unit, and how do I know when the valves need replacing?
We would normally estimate around 4 years, but much will depend on the way the units are used. Leaving units powered up permanently will certainly reduce the valve life – we would recommend that the unit is switched off at the end of a session (although our use of dc heater supplies reduces the fatigue on the valve heaters). Traditionally, as a valve starts to deteriorate with age, its HF performance will be affected, so that there is a perceived loss of brightness, and the sound tends to become “woolly”. TL Audio products make extensive use of localised internal feedback circuitry to ensure that if a valve’s characteristics change with time then the performance of the unit is not compromised – thus extending the useful life of the valve.
