Fidelity-Research XF-1

Commentary

Toroidal step-up transformer designed exclusively for low impedance MC type cartridges.

The transformer core material is made of super-permalloy-based alloy, which has about four times the core volume of conventional core material. In order to take advantage of the superior characteristics of this core material, we have adopted a ring-shaped core with a laminate structure in which hundreds of concentric layers of 0.05 mm-thick rolled core material are wound in concentric circles, further improving the high-frequency characteristics.
In addition, by applying special hardening and insulating treatment to the surface of the core, the conventional core casing is not required, and the toroidal winding is applied almost in the state of close contact winding, so the winding length can be shortened even though the core volume is increased, and signal transmission loss is reduced.

In order to make the left and right channels exactly the same condition, the toroidal transformer unit, the shield drain and the left and right channels of the output are completely independent. This greatly reduces the electrical and magnetic crosstalk of the left and right channels.

Careful 4-layered shield made of 78% permalloy prevents the influence of external induction etc.

0.8 φ mm oxygen-free copper wire is used for the internal wiring material to improve the vibration and transmission loss of the wiring itself. In addition, the toroidal transformer unit has achieved 1/2 or less resistance on both primary and secondary sides by winding, contributing to the improvement of transformer conversion efficiency and the increase of information quantity.

The input / output terminals use highly reliable, high contact pressure pin jacks and pin plugs with thick film, hard gold plating.

Model Rating

Type	Low-impedance dedicated booster transformer
Input (primary) impedance	3 Ω or less
Load (secondary) impedance	47k Ω ~ 50k Ω
Boost ratio	36dB
Playback frequency range	5 Hz to 50 kHz
Output cord length	70cm
External dimensions	Width 158x Height 65x Depth 120 mm
Weight	2.1kg