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For this purpose, the equalization curve applied during record manufacture must
be known. Quite a number of equalization curves were used over the decades
however, among which the 'RIAA' curve became the most widespread - named
after the Recording Industry Association of America.
Other equalization curves one may encounter are 'NAB' (National Association of
Broadcasters) or 'BBC' (British Broadcasting Corporation), which can also be
properly handled by the PPA V600 when set accordingly.
Both these curves have effect on treble reproduction, just like the 'FLAT' curve
which does not imply high-frequency equalization at all.
Furthermore, a 20 Hz high-pass or 'rumble' filter according to IEC (International
Electrotechnical Commission) can be switched into circuit.
See also: diagram on page 17 !
The PPA V600 offers individual signal paths
Why are individual signal paths so favourable ?
Most operational amplifiers are designed as two amplifiers integrated in a single
package. If the left and right channel signal are processed by the circuit at the
same time, a certain mutual interference is inevitable. The adverse effects may
be marginal only, but should be excluded during the design process wherever
feasible.
The PPA V600 contains numerous operational amplifiers
Why are operational amplifiers ideal for small-signal processing ?
High-end audio gear often follows a 'discrete' design, meaning that the amplifier
stages are composed of single transistors. This feature is often presented as an
optimizing measure, but finally the related high manufacturing effort is to be paid
by the customer.
Certainly an operational amplifier is made of transistors as well. Its design
however offers the advantage of thermal coupling of its individual components,
and ageing issues play a negligible role.
Since the choice of OP-amps on the market is huge, an ideal model for any
special application can be found.
The PPA V600 is powered by switching-mode power supplies
Why are switching-mode power supplies ideal for phono preamps ?
An equalizing preamp boosts low frequencies and therefore does right the same
with hum interference radiated by a mains transformer. Thus, conventional
transformers are 'audible' in many cases, sadly...
Summary of Contents for PPA V600
Page 1: ...1 PHONO PRE AMPLIFIER PPA V600 USER s MANUAL ...
Page 9: ...9 Connection Connectors for analog signals ...
Page 17: ...17 EQUALIZATION CURVES ...
Page 26: ...26 ...