Moving coil input

Moving coil input transformers

Moving coil cartridges are low voltage devices. Typical output levels are below
1 mV, and often as low as 0.1 mV. In order to generate 12.5W on an 8 ohm loudspeaker, a 0.1V signal must be amplifier 100000 times (or 100 dB). In particular for tube amplifier devices, such a high amplification is very hard to achieve without significant noise additions and signal degradation.

The purpose of using Moving Coil Step-Up Transformers (MC SUTs) is to step up/increase the low output signal voltage from moving coil cartridges before the signal enters the phono stage. As MC cartridges are very low impedance devices, transformers can successfully be used to raise the signal level 20 – 30 dB without any noticeable degradation. This reduces the required remaining amplification significantly.

When you choose between different MC SUTs, we normally suggest that you choose a step-up ratio based on the cartridge output impedance as follows:

Low impedance (1 – 10 ohms) step-up ratio 32 – 24
Medium impedance (10 – 40 ohms) step-up ratio 24 – 8
High impedance (> 40 ohms) step-up ratio < 8

Low turns ratio MC SUTs (turns ratio around 1:5) are sometimes used also with low impedance cartridges when combined with solid state phono stages.

Lundahl Transformers make MC SUTs with two different types of core; mu metal (nickel) lamination core and uncut amorphous cobalt strip core. The laminated mu metal core is the most classic and commonly used core material. It provides high permeability also at small signal levels, low distortion and a transparent sound. Our uncut amorphous strip cores are sometimes said to be more musical, but due to a lower initial permeability they are slightly less linear.

Our more prestigious range of SUTs are wound with Oxygen Free Copper (OFC), and some are also available with silver wire.

For more information on MC SUTs, and how to apply proper loading to cartridges, we suggest you visit this page at our US distributor Erhard Audio LLC:

https://www.erhard-audio.com/SUT_Calculations.html

moving coil step-up transformer preamp

The MC1 Moving Coil Lundahl Step Up Transformer Preamp provides you with a moving coil SUT unit, built, tested and matched to your cartridge offering a range of Lundahl transformers and loading options to meet any need.

Orso Audio

Erhard Audio offers a wide range of Lundahl Moving Coil Step-Up Transformers for vinyl systems using low-output MC cartridges. These transformers help raise the delicate cartridge signal before the phono stage, reducing the need for excessive amplification and helping preserve low-noise musical detail. With options in mu-metal, amorphous core, OFC and silver wire versions, the range supports different cartridge needs and listening preferences.

Erhard Audio LLC

The Orso Audio MC1 DIY Kit is a complete parts kit for building a moving coil step-up transformer preamp with Lundahl MC SUTs.

Acclaimed Performance in High-End Analogue Audio

The Lundahl LL1941 moving coil step-up transformer has recently received strong praise in a detailed review by Michael Fremer, one of the most respected voices in high-end analogue audio.

In his review of the Erhard Audio Premium MC Step-Up Transformer, Fremer highlights the natural musicality, transparency and effortless dynamics delivered by the LL1941. The review underscores the importance of a well-designed transformer at the MC input stage — where signal integrity, low noise and tonal accuracy are critical.

This recognition confirms the LL1941 as a trusted choice for demanding moving coil applications where musical authenticity matters most.

Go to review

Designed for cartridge matching

One of the strengths of using MC step-up transformers is the ability to match the transformer to the cartridge.

Different cartridges have different output levels and internal impedances. This means that the step-up ratio matters. Lundahl normally recommends choosing the ratio based on cartridge output impedance, with higher ratios often used for low-impedance cartridges and lower ratios for higher-impedance cartridges.

The Orso Audio MC1 DIY Kit supports a wide range of Lundahl MC SUT options, including LL1678, LL1678XL, LL9226, LL9226XL, LL1933, LL1931, LL1971, LL1943, LL1941, LL1963 and LL1961. This gives the builder flexibility to choose a transformer solution that suits the cartridge, phono stage and desired listening result.

For the listener, this is not only a technical detail. Correct matching can help the system feel more open, balanced and natural — allowing the musical information from the cartridge to reach the phono stage in a controlled and elegant way.

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Type	Stepup Ratio	Core	Wire	Size LxWxH	Comment
LL1678	8, 16, 32	Amorphous	Standard	30x23x15	Small size
1678XL	8, 16, 32	Amorphous	Standard	33x27x16	Bigger core, lower resistance, LL1678 pinout
LL1681	13, 26	Mu metal	Standard	48x29x20	With Faraday shields
LL1931	8, 16	Amorphous	OFC	43x29x22	Premium
LL1931Ag	8, 16	Amorphous	Silver	43x29x22	Super premium
LL1933	8, 16	Mu metal	OFC	47x28x24	Premium
LL1933Ag	8, 16	Mu metal	Silver	47x28x24	Super premium
LL1941	16, 32	Amorphous	OFC	43x29x22	Premium
LL1941Ag	16, 32	Amorphous	Silver	43x29x22	Super premium
LL1943	16, 32	Mu metal	OFC	47x28x24	Premium
LL1943Ag	16, 32	Mu metal	Silver	47x28x24	Super premium
LL1961	3.2, 6.4	Amorphous	OFC	43x29x22	Premium. With Faraday shields. For solid state systems.
LL1963	3.1, 6.2	Mu metal	OFC	47x28x24	Premium. With Faraday shields. For solid state systems.
LL1971	12, 24	Amorphous	OFC	43x29x22	Premium
LL9226	5, 10, 20	Amorphous	Standard	30x23x15	Small size
LL9226XL	5, 10, 20	Amorphous	Standard	33x27x16	Bigger size, bigger core. LL9226 pinout.