Something that has puzzled me for a long time is the trend these days to have valve amplifiers all polished up in full view. Does it affect the quality of the sound at all? Can anyone with Golden Ears hear any difference?
Yes it can affect the valve operation when the valves are exposed to the light, and it is not good news at all. Possibly the designers of high quality valve amplifiers in their heyday knew something that was not well known and they were designed to be used out of direct light in well ventilated places. Leak and Quad come to mind and of course there were many others.
Of course you can check it out for yourself if you are using an amplifier with valves exposed to the light. Play a particular piece of music in full light, then again play it with all illumination removed and see for yourself if you can perseive any difference.
In one of my notebooks from some years back I copied out a very short item from an American technical magazine (possibly it was "Electronics" magazine) which referred to an original German article which read as follows.
VACUUM TUBE PERFORMANCE AND ILLUMINATION
( L Pungs and K Schulze) of Brunswick Institute of Technology. Although the experiments described relate to Telefunken screen grid tubes with oxide coated cathodes they are of interest because some American firms claim that tubes work better when light is excluded. It is found that changes depend on the presence of the mirror formed by the getter material which loses electrons when illuminated. It might also manifest itself as a slight increase in plate current and may result in the perceived clarity when reproducing recorded music.
Zeitschrift f Hochfrequenz Technik.
Of course anyone using those lovely all metal 6L6 and rectifier valves can place their amplifiers where they like as illumination will make no difference.
Yes it can affect the valve operation when the valves are exposed to the light, and it is not good news at all. Possibly the designers of high quality valve amplifiers in their heyday knew something that was not well known and they were designed to be used out of direct light in well ventilated places. Leak and Quad come to mind and of course there were many others.
Of course you can check it out for yourself if you are using an amplifier with valves exposed to the light. Play a particular piece of music in full light, then again play it with all illumination removed and see for yourself if you can perseive any difference.
In one of my notebooks from some years back I copied out a very short item from an American technical magazine (possibly it was "Electronics" magazine) which referred to an original German article which read as follows.
VACUUM TUBE PERFORMANCE AND ILLUMINATION
( L Pungs and K Schulze) of Brunswick Institute of Technology. Although the experiments described relate to Telefunken screen grid tubes with oxide coated cathodes they are of interest because some American firms claim that tubes work better when light is excluded. It is found that changes depend on the presence of the mirror formed by the getter material which loses electrons when illuminated. It might also manifest itself as a slight increase in plate current and may result in the perceived clarity when reproducing recorded music.
Zeitschrift f Hochfrequenz Technik.
Of course anyone using those lovely all metal 6L6 and rectifier valves can place their amplifiers where they like as illumination will make no difference.
