Before talking about MC step-up transformers, let's first discuss the basic way of enjoying records. When listening to a record on a turntable (record player), the needle converts the sound information engraved in the grooves of the record into a music signal for playback.
Generally, the preamp section of integrated amps or separate amps comes with a dedicated PHONO (phono equalizer) input for listening to records. You connect the output terminal from the record player to this phono input to listen to music.
Record cartridges (needles) are broadly divided into two types based on their method of generating an electrical signal from the record's sound: 'MM (Moving Magnet type)' and 'MC (Moving Coil type)'.
When records were commonly found in households, the needles were mostly MM type. The MM type, with its high output voltage and ease of use, can be directly connected to an amp with a phono input for record listening. Therefore, many MM types are inexpensive and durable.
Cartridge product page here
https://www.exclusive-audio.jp/shop/products/list.php?category_id=27
The other type, the MC (Moving Coil) cartridge, has a more complex structure and requires higher precision compared to the MM type. It has good sound response, a wide frequency range, and above all, superior sound quality. Generally, the image of an MC cartridge is 'expensive and high-performance,' and the main products are mid to high-end models. In fact, among audio enthusiasts, MC cartridges are overwhelmingly used, and there is a wide variety of products available.
However, due to its structure, the MC type has a lower output voltage compared to the MM type, with less than 1/10 of the MM type's output, typically around 0.1 to 0.3 mV.
Therefore, if you connect it directly to the amp's phono input, the volume is too low to use effectively. For this reason, a step-up transformer or head amp is required to raise the output voltage to the MM level without degrading sound quality.
Since it is dedicated to MC cartridges, it is also called an 'MC transformer' or 'MC head amp.'
Step-up transformer product page here
https://www.exclusive-audio.jp/shop/products/list.php?category_id=26
Step-up transformers are used more widely than head amplifiers. There is also a wide range of products, with various designs in shape and size, and the prices vary greatly. The step-up ratio differs depending on the winding ratio of the transformer, and the input impedance is divided into two types: HIGH and LOW. Because the mechanism is simple, differences in the performance of the core and winding materials, as well as structural differences, greatly affect the sound. This results in each having its own character, with direct and powerful playback being a characteristic feature.
Here is the product page for head amplifiers.
https://www.exclusive-audio.jp/shop/products/detail.php?product_id=22
On the other hand, head amplifiers electronically increase the input signal using amplification elements (such as semiconductors), so a power supply is required. In terms of sound quality, many tend to be flat and wide-ranging.
Step-up transformers, not having a power section, are strong against noise and have excellent stability, but the environment they are placed in can cause noise due to external influences, and if the ground wire is not properly connected, hum can occur, so caution is necessary. Some head amplifier models may require countermeasures against noise around the power supply due to the flow of current.
When choosing a step-up transformer for an MC cartridge, broadly, there are LOW impedance and HIGH impedance types, so select a step-up transformer that matches the impedance as much as possible.
Here is the product page for phono equalizers.
https://www.exclusive-audio.jp/shop/products/list.php?category_id=33
Besides the phono equalizers built into preamps or integrated amplifiers, there are also standalone phono equalizer amplifiers. Depending on the product, there are models with MM input only, MC-compatible models with a built-in step-up transformer, and equalizers that provide ideal amplification for MC cartridges using large current output. This allows you to choose combinations or models according to your preference.
