MCL step-up transformer

Rothwell MCL step-up transformer

The Rothwell MCL step-up transformer, equipped with Lundahl transformers, is a premium audio transformer developed to increase the output voltage of moving coil (MC) pickup elements to the level of moving magnet (MM) elements. This allows users to utilize high-quality MC cartridges in combination with phono preamps designed primarily for MM cartridges. For example, many tube phono preamps are only suitable for MM.

The core of the MCL consists of two top quality Lundahl transformers, supplemented with dedicated primary and secondary charging networks for optimal performance, resulting in an exceptionally wide bandwidth (up to 70kHz).

For optimal signal-to-noise ratio, it is recommended that the transformer be located away from large mains transformers (such as those in amplifiers) and that high-quality, low-capacitance, shielded interconnection cables be used, ideally no longer than 1 meter, between the transformer and the phono preamplifier. The Rothwell River connecting cables are ideally suited for this.

Despite the increase in available MC phono preamps (both built-in and external), many still prefer the combination of a quality step-up transformer and an MM phono preamp for using MC cartridges. When using a tube phono preamplifier with an MC element, a step-up transformer is essential for acceptable performance and signal-to-noise ratio. The scarcity of MC step-up transformers is due to their complexity and high production costs. However, the performance of a well-designed transformer is unparalleled.

The Rothwell MCL Step-Up Transformer is now available to deliver excellent performance with low output MC elements (recommended output level of 0.3mV - 0.6mV). The bandwidth is wide and flat, with special attention paid to the transient response. The dimensions are 100 x 155 x 60 mm.

Specifications:

• Conversion ratio: 1:20
• Voltage gain: 26dB (x20)
• Input impedance*: 100 ohms
• Optimal load impedance**: 47k + 150pF
• Core material: cobalt based amorphous strip
• Bandwidth: 8Hz - 75kHz
• Cartridge compatibility (output): 0.2mV - 0.7mV
• Cartridge compatibility (impedance): <20 ohms
• Dimensions: 60 x 155 x 92 mm
• Weight: 580g