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10. PHONO MC OPTION
10.1. 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.
10.2. The phono section of the HP 300 MK2 MKII
The phono section of the HP 300 MK2MKII 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 MC head amp that successfully eliminates the problem areas. At the
heart of the equalizer is a tube circuit containing 1 tube and two integrated circuits. It
incorporates a switchable subsonic filter, which prevents very low frequencies generated by
warped records or tone arm resonances from overloading the loudspeakers.
(
A
)
10.3. Guidelines for connecting to the phono section
1. Plug the RCA phono cable from your turntable into the appropriate (phono MC
) input
on your HP 300 MK2. Turn the input selector
to phono
.
2. Connect the earth cable supplied with your turntable to the GND connection on the
HP 300 MK2
, 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.
Содержание HP 300 MK2
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