Ortofon ST M25 transformer

Specific for SPU Mono and 78 rpm

12 dB gain

Transfo Mono

Made in Japan

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Manufacturer : ORTOFON

559,00 €

Shipped within 3 to 5 working days Available within 1 or 2 weeks


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The Ortofon ST M25 transformer is only designed for the Ortofon SPU Mono CG 25 DI MKII and SPU CG 65 DI MKII MC cartridges.


Of course, the output level of Ortofon’s cartridges is too low for a MM input. It is often unsuitable for traditional MC cartridges, which offer too much gain. Indeed, the output level of these SPU is 1.5 mV, which makes them a little atypical.

The ST M25 is specially designed to increase the voltage by 12 dB and to match the inputs of phono preamplifiers with a gain between 38 dB and 44 dB.

As both cartridges are monophonic, they supply the same monaural signal from both L and R channels. Therefore, the L and R channels of the turntable must be connected via the Ortofon ST M25 to the preamplifier.

The Ortofon ST M25 is equipped with a mono coil, so the signal is fully neutral.


Associated to the SPU Mono CG 25 DI MKII and SPU Mono CG 65 DI MKII cartridges, the Ortofon ST M25 transformer provides a powerful and dynamic restitution, while remaining accurate to the sound quality of early monophonic recordings.


Recommended cartridge impedance: 5-50 ohms

Gain: 12 dB at 1 kHz

Bandwidth: 10 Hz - 100 kHz (+/- 1 dB)

Output: 47 kOhm / 200 pF

Dimensions: 65 x 39 x 98 mm

Weight: 0.410 kg

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Ortofon ST M25 transformer

Ortofon ST M25 transformer

Specific for SPU Mono and 78 rpm

12 dB gain

Transfo Mono

Made in Japan

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