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MCL Moving Coil Step-Up Transformer

MCL

The MCL is a step-up transformer designed to raise the output of moving coil cartridges up to a level compatible with moving magnet phonostages. The purpose is not simply to allow moving coil cartridges to be used with moving magnet only phonostages (which most valve designs are, for example), but to allow moving coil cartridges the chance to realise their full potential. Transformers have much more benign distortion characteristics than active circuits and they are capable of producing a truly sublime soundstage with detail and separation unsurpassed by the more common transistor and op-amp alternatives. Don't be misled that transformers are an audio anachronism long since made obsolete by the wonders of modern solid state technology - they're not. The reason that they are so rarely seen nowadays is that transformers are incredibly expensive compared to transistors and chips. A complete moving coil compatible phonostage is obviously more convenient than a separate transformer and moving magnet phonostage, and a moving coil phonostage made entirely with solid state circuitry is considerably cheaper to produce than one with transformers, hence the rarity of moving coil step-up transformers. This is shame because many audiophiles have never even heard a transformer coupled moving coil cartridge and don't know how good it can sound.

The MCL uses transformers supplied by Lundahl of Sweden and is a superb step-up transformer designed specifically for modern low output moving coil cartridges and optimised for use into moving magnet phonostage inputs. 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 makes it compatible with a wide range of cartridges and our proprietary loading networks maintain a 100 ohm input impedance, also compatible with a wide range of cartridges.

step-up transformers explained
Although the MCL is compatible with most moving coil cartridges available today from makers such as Lyra, Koetsu, Ortofon, Audio Technica etc., anyone confused by the whole topic of impedances, transformer ratios and matching can read moving coil step-up transformers explained for detailed information on the subject, along with example calculations and a useful table of cartridge data for guidance in assessing compatibility.
For information about transformer choices for Denon cartridges, see step-up transformers for Denon cartridges.

specifications

turns ratio
voltage gain
core material
input impedance*
optimum load impedance**
bandwidth
cartridge compatibility (o/p)
cartridge compatibility (imp.)
dimensions
weight

1:20
26dB (x20)
cobalt based uncut amorphous strip
100 ohms
47k + 150pF
8Hz - 75kHz (+0/-3dB)
0.2mV - 0.7mV
internal impedance <20 ohms
60 x 155 x 92 mm
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.

“...there it was! That jaw dropping detail I had been looking for”
Paul Stewart
full review

How to buy
The cost is 485 (uk retail) and units can be obtained from our hi-fi dealers (full list) or by contacting Rothwell Audio Products directly by email or telephone (+44 (0)1204 366133) or from the online shop.

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