Rega Ios Reference - Manual (Page 11)

FILTER CONTROL
The filter is designed to enhance the Apheta cartridge by reducing unwanted
high frequency energy present. The level is continuously variable from 0db to
–6.5dB at a frequency and ‘Q’ chosen to match that of the Apheta cartridge. As
a rough guide the filter is useful with older (early 1960’s) pressings with
higher than normal surface noise, typical position being roughly 1 o’clock. Later
and newer recordings may not need this filter. When the filter switch is in the
off position the filter is completely removed from the signal path. The filter is a
‘notch’ filter working at around 8.5Khz. It may sometimes improve the sonic
performance of various makes of MC cartridges that are a little ‘bright’
sounding or under damped in construction. Note: The filter is only for use in
some circumstances. If you find that the filter does nothing or degrades the
sound, simply switch it off.
LOAD SWITCH
The DC resistance of the cartridge affects the transient or square wave
response of the transformer; this network has to be optimised to get the best
out of the cartridge and transformer combination. There are five different
input load settings of 50Ω, 100Ω, 150Ω, 300Ω
& 400Ω. Select the required
load to match to that specified by the manufacturer in the cartridge
specifications. It is permissible to try different loading conditions as some-
times changing the load gives a different sonic performance more suited to
your personal taste. The 100Ω setting is optimised for the Rega Apheta MC
cartridge.
MUTE
Allows you to mute the signal in-between tracks or when changing records.
MONO
This functions allows you to play mono recordings via a stereo cartridge.
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