[Techman]

It's true that with a low tracking weight Hi-Fi turntable playing LPs, that needle chatter is no longer a problem and actually fitting the lid while playing can enhance any rumble that may be present.

I thought that I may have been pulled up on some of the exceptions to the closed lid with no ventilation problem. Radiograms often have no lid ventilation, but they don't need it due to the large amount of cabinet ventilation usually provided in the back cover. What about acoustic 'howl'? Well you often notice the complete brown felt lining on the inside of these lids to negate this. The Pye Black Box is another example of a totally closed lid with no ventilation. These have plenty of air space under the deck with ventilation holes giving good (hopefully) convection ventilation at the rear. The amplifiers in these players don't generate excessive heat like some of the live chassis types do with droppers etc., in a confined space. The Black Box has a heavy lid with felt all around the mating edge, so no 'howl' and I understand that the lower frequency response of the amplifier was carefully designed to help to negate any the might have occurred. The Black Box sounds at its best with the lid closed while playing.

Most other record players that have the amplifier at the front with some sort of ventilation holes or grille venting straight into the under lid deck space have to vent their hot air across the top of the record deck and out through the ventilation usually provided at the rear of the lid. I think the live chassis amplifier models tend to be the worst offenders with regards to generating unwanted extra heat within the above platter area.