inches) and accordingly position the tone arm at the start of the disc (its outer edge). Some used a variable-size sensor which allowed sizes other than the standard three to be played. The simpler models required the record diameter to be set manually, and hence did not allow records of different sizes to be stacked together. The following automatic size detecting devices were the most popular (with examples): Three-size sensors: Size-selector knobno size intermix (BSR, 1968 to 1980s). Size- and speed-selector knobno size intermix, so that some types couldn't be played automatically (Garrard after 1969). Rising feelers in or alongside turntableno size intermix, but automatic sensing of size (PE after 1970) Falling record sensorrandom intermixsizes mixed in any order (BSR before 1968. Garrard Auto-Slim variants. Some RCA. Silvertone.). Rising and falling record sensorsintermix 10- and 12-inch records vs. separate playing of 7-inch (VM 1950 to 1970. Admiral Ensign series.). Unplayed stack sensorarranged intermix, large records before small (Webster Chicago 1950 to 1953) Unplayed stack arm tip sensorarranged intermix (Collaro/Magnavox after 1967) Variable-size sensors: Pickup arm scan of unplayed stackarranged intermix, odd sizes (Collaro/Magnavox 1954 to 1967) Pickup arm scan of lowered recordrandom intermix, odd sizes (PE 1957 to 1969) Arm tip feeler wheels (feel only top record on turntable)random intermix, odd sizes (Dual 1003, 1004, 1005, 1006) Arm top feeler wheels (feel only bottom record on stack)random intermix, odd sizes (Miracord 9 and 90) Pickup arm scan of separated recordrandom intermix, odd sizes (Thorens TD-224) Audiophiles eventually disdained record changers because of the perceived compromise in fidelity resulting from changes in tone arm angle with the height of the stack, and concerns about changers' seemingly rough treatment of discs, particularly due to slight but cumulative damage to the spindle holes as the records were dropped from a height of a few inches onto the record or stack below or the turntable platter; as well as some sliding and rubbing of the discs together, scratching the record labels in the process, because the dropped disc didn't immediately accelerate to the rotational speed of the spindle or discs below it. Most of these fears were unfounded in changers made after 1953. More advanced changers, such as the TD-224 model from Thorens and the ADC Accutrac+6, partially addressed these problems. Automatic sequencing Numbering of the sides of the discs in many double and triple albums, and boxed sets of records (both 78s and