MatrixS2000 wrote:My cartridge outputs 0.3mV at 3.54cm/s with an internal impedance of 7.2 Ω.
The 3.54cm/s (one channel only) is a different expression of the typical 5 cm/s (left and right channel driven).
Just a different way of measurement.
This way the 0.3 mV (one channel) equals 4.2 mV (both channels).
Factored with x10 from the Sowter 1480 you’d end up with 4.2 mV output, in the lower part of the normal range of what MM pickups offers.
The load impedance the cartridge sees would be 450:Ohm (ADI-2’s input impedance of 47,000 Ohm is transformed with the square of the transformer ratio), unnecessary high.
MatrixS2000 wrote: If the 1480 does not provide enough gain, they also provide a 1:20 option.
The Sowter 1990 1:20 transfomer would be a better match:
https://www.sowter.co.uk/specs/1990.php
Output 8.4 mV, cartridge load 113 Ohm.
The 6 dB higher output results in a better S/N ratio.
With it’s widely variable input reference level (gain) ADI-2/4 Pro SE can easily handle the higher input voltage, as my practical experiences showed.
Watch out: the description text for the 1990 primary wiring is wrong:
Primary series connection = 1:10, parallel = 1:20
For 1:20 link grey with red, and orange with white.
For 1:10 link orange with red, and use grey and white for input.
The interconnect cables transformer to ADI-2 should be as short / low capacitance as possible.
BTW: the Ortofon T-20 won’t fit, the T-30 would.