The purple trace shows the group delay, which is easier to understand, since it is the time a signal needs to pass the
electronic.
If we consider a complex signal with 20Hz as the fundamental, then the fundamental of the signal needs 4ms from the input
to the output. The second harmonic needs only 1.5ms. That means you will hear the harmonics before you hear the
fundamental!
It is said, that the gifted people with “Golden Ears” can hear differences of 50µs.
This deviation is reached with a 20Hz high pass at 250Hz. From there on the system is time coherent for the ears.
A few millisecond group delay variation is therefore not time coherent and the reason why the DC servo in the TRINITY
PHONO PREAMP starts at 0.5Hz.
To avoid such a step-up transformer the TRINITY PHONO PREAMP uses 12 gain stages in parallel to reduce the input noise
voltage and thereby the optimum source resistance by a factor of
12
3.5 10.8
dB
=
≡
Of course you can write just anything down on paper, but what about the reality.
The next figure shows the inverse RIAA used as an input signal for the PHONO PREAMP.
The amplitude simulates a pickup with 150µV at 1kHz.
