Re: [ARSCLIST] RIAA EQ software

[Scott Phillips <scottp@xxxxxxxxxxxxxxxxxxx>]

I used a test record, an impedance bridge, and a lot of reading of
manufacturers data. I wasn't going to use a transformer for matching,
and the preamp I constructed had about a 100k input impedance. Using the
cartridge manufacturer's data as a starting point, it seemed in my
particular case that the cartridge wanted to see about 100 ohms x 1.5mf
sort of additional load. This made for the flattest response.

I am by no means an expert in this area, and since LPs are only a casual
interest to me (tape is my thing), this is only an approximation at
best. There are limits to the parts values at hand for the 'cut 'n try
in my case. The loading networks were tacked directly on to the input
terminals of the preamp for each try.

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Andrew Hamilton
Sent: Tuesday, August 26, 2008 6:09 AM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: Re: [ARSCLIST] RIAA EQ software

How did you modify the load as seen by the cartridge in order to make
the
ADC "look" like an ideal phono preamp's load for the chain?  - a y-cable
with a resistor on the unused end, so that the combined Z (of the ADC
and
the resistor) equaled the output Z of the cartridge? Or by some other
network?


Andrew


On 8/26/08 1:42 AM, "Scott Phillips" <scottp@xxxxxxxxxxxxxxxxxxx> wrote:

> The loading of the cartridge was one of the first things I checked
out.
> As a cartridge is obviously a coil of wire (an inductor) and has
> capacitance, nothing could even start to be right without setting up
> proper loading for the particular cartridge.