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9. PHONO MM/MC OPTION
9.1. Description
The role of the phono preamplifier
A record player is an electro-mechanical device. Music signals are "pressed" into the grooves in
the record, and these are physically tracked and read by the pickup cartridge. In order to get the
entire 20 Hz - 20 KHz frequency range into the grooves, the frequency response has to be
shaped by lowering the level of the low frequency information and raising the level of the high
frequency information. This predefined equalization curve is known as RIAA equalization.
A phono amplifier must exactly equalize for RIAA recording characteristic if it is to avoid
colouring the sound. Equalization accuracy must be within 0.5 dB over the entire frequency
range, with channel matching of at least 0.1 dB.
The phono section of the HP 500 SE
The phono section of the HP 500 SE is an enhanced version of our hybrid phono technology.
The phono section now offers a greater level of compatibility with low output and low impedance
moving coil cartridges. Most preamps have problems with such cartridges, since both gain and
input impedance issues have to be addressed simultaneously.
We have developed an MM/MC head amp that successfully eliminates the problem areas. At
the heart of the equalizer is a tube circuit containing 3 tubes. It incorporates a switchable
subsonic filter, which prevents very low frequencies generated by warped records or tonearm
resonances from overloading the loudspeakers.
Guidelines for connecting to the phono section
1
Plug the RCA phono cable from your turntable into the appropriate (MC
or MM
) input
on your HP 500 SE. Turn the input selector
to phono
.
2. Connect the earth cable supplied with your turntable to the GND connection on the
HP 500 SE
, following the instructions provided by the turntable/arm manufacturer.
Some tonearms do not have a separate earth cable, as the pickup system is earthed via
the RCA phono plugs.
Explanation:
The earth is generally connected to the tonearm or the headshell. This is necessary to
prevent hum or radio interference. It is usually advisable to connect the earth cable to
reduce this kind of interference.
Summary of Contents for HP 500 SE
Page 1: ...HP 500 SE...
