Rothwell MCX Lundahl Phono Step-Up Transformer

This step-up transformer uses the same high quality cores as used in the MCL, again supplied by Lundahl of Sweden, but features a lower turns ratio than the MCL to accommodate cartridges with higher outputs.

The turns ratio of the MCX is 1:10, making it compatible with cartridges with outputs of up to 0.9mV, which includes models from Benz Micro, Clearaudio, Koetsu, Lyra and Van den Hul.

It features very wide bandwidth, low distortion and carefully designed primary and secondary loading networks to optimise the performance and give beautifully reproduced transients, free from ringing.

The core materials and winding techniques employed in the manufacture are unsurpassed and feature multiple primary and secondary windings configured to cancel hum pickup from external sources as well as minimise inter-winding capacitance and maximise bandwidth. The step-up ratio of 1:10 makes the MCX is compatible with a large selection of moving coil cartridges available today from makers such as Benz Micro, Clearaudio, Lyra, Koetsu, Ortofon, Audio Technica etc., but is particularly suited to cartridges with higher than average outputs, those in the range 0.6mV to 0.9mV.

step-up transformers explained
The whole topic of step-up transformers, impedance matching, cartridge compatibility etc. can seem quite baffling, though it doesn’t have to be as complicated as is sometimes claimed. Our useful guide to the topic of impedances, transformer ratios and matching, moving coil step-up transformers explained, gives accessible but detailed information on the subject, along with example calculations and a useful table of cartridge data for guidance in assessing compatibility.

Specifications:
turns ratio: 1:10
voltage gain: 20dB (x20)
core material: cobalt based uncut amorphous strip
input impedance*: 100 ohms
optimum load impedance**: 47k + 150pF
bandwidth: 8Hz - 75kHz
cartridge compatibility (o/p): 0.35mV - 0.9mV
cartridge compatibility (imp.): <20 ohms="" br=""> dimensions: 60 x 155 x 92 mm
weight: 580g

*This is the load presented to the cartridge.
**This is the optimum load for the transformer, ie the input impedance of the phonostage that the MC1 feeds into.