Re: [ARSCLIST] RIAA phono EQ and Neumann time constant

[Goran Finnberg <mastering@xxxxxxxxx>]

I wrote:

> The total error at 20 Khz is around -0.15 dB.

A slight error in my assumptions:

After having simulated the very slightly peaked Sallen & Key unity gain
active two pole butterworth filter set to - 3 dB @ 50 kHz as followed by
a single pole at 96 kHz this gives:

A roll off of about - 0.08 dB @ 20 kHz and the total response is down -
3 dB near 40 kHz.

This includes the 75 µS time constant of the RIAA preemhasis which is
almost perfectly set by the components used, precision types C & R.

The final 3 pole response is closer to a Bessel than a Butterworth
alignment.

So if any one worries about those miniscule errors up to the cutter
amplifier + moving coil cutter then relax.

It is of NO consequence at all imo.

Far greater errors rest elsewhere and now I will promptly forget the
whole thing.

I apologise to be boring the list with such absolute miniscule trivia.

-- 
Best,

Goran Finnberg
The Mastering Room AB
Goteborg
Sweden

E-mail: mastering@xxxxxxxxx

Learn from the mistakes of others, you can never live long enough to
make them all yourself.    -   John Luther