There's a conceptual abstraction of the ideal amplifier discussed among electronic designers: the famously touted "piece of wire with gain".
Now, here we literally have it: The Consolidated Audio "Monster Can" MC step-up transformer is exactly that! Choosing the lowest loss and highest permeability core materials and combining these with an optimized winding technique to minimize and balance the stray components inherent in any transformer design enables us to provide passive voltage amplification with just a piece of wire! Utilizing the drive capability of low impedance MC phono cartridges we thus can eliminate the active "pre-pre" or high-gain MC phono stage with their often noisy performance and tendency to mask low level detail.
Consolidated Audio "Monster Can" MC StepUp Transformers are available based on two different soft magnetic core materials:
Hi-Nickel (80% Nickel aka MuMetal)
The "classic" material for high quality, low level audio signal transformers. Musical and coherent, bodily presentation.
A "state of the art" core material for wide bandwidth, low loss audio signal transformers. Detailed and spacious. Airy and elegant, effortless presentation.
Since the step-up transformers primary inductance sets the low cutoff frequency it is chosen after the cartridge impedance. The Consolidated Audio MC StepUp Transfomer is currently offered for three ranges of cartridge impedances:
If your preferred cartridge has an impedance smaller than 10 ohms we recommend a step-up transformer with low primary inductance.
Examples: Ortofon SPU, Lyra
If your favourite cartridge's impedance is between 6 and 20 ohms a step-up transformer with medium primary inductance is most suitable.
For MC phono cartridge impedances between 12 and 40 ohms we recommend a step-up transformer with high primary inductance.
Examples: Denon DL 103, EMT TSD
The step-up transformer turns ratio determines the passive voltage amplification factor together with the cartridge loading by the phono stage input impedance. One approach to frontend optimization therefore is the matching of nominal cartridge output voltage to the nominal input voltage of an MM phono stage (usually 5 mV). A second approach gives priority to cartridge loading by the transformed input impedance of the MM phono stage (usually a 47 k resistor in parallel to input + cable capacitance)
Low Ratio (1:10 / 20 dB)
By using a step-up transformer with a 1:10 turns ratio a cartridge with a characteristic output voltage of 0.5 mV @ 5 cm/s would meet the standard input voltage requirements of an MM phono stage. Resistive loading of such phono pickup would be 470 ohms since the SUT transformes impedances by the square of its turns ratio.
Medium Ratio (1:15 / 23.5 dB)
For cartridges of ca. 0.35 mV @ 5 cm/s. Cartridge loading by the transformed charactersistic MM phono stage input resistance is approx. 210 ohms.
High Ratio (1:20 / 26 dB)
For cartridges of ca. 0.25 mV @ 5 cm/s. Cartridge loading approx. 120 ohms.
Consolidated Audio "Monster Can" step-up transformers can be built with copper or 99.99% silver windings (mixed configurations are also possible). Please consult the extensive information available on the web to inform you of advantages and disadvantages of either material.