Ortofon ST-90 MC Step Up Transformer
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Ortofon ST-90 MC Step Up Transformer


The new ST-90 MC transformer from Ortofon that supports balanced input (XLR) and output, as well as RCA input and output. ST-90 is the successor of ST-80 SE.

SKU: 4571106662653 Categories: , , Tag:

Product Description

The ST-90 Moving coil transformer delivers a detailed reproduction with a touch of warmth accompanied by a full bodied sound quality. The frequency response is wide and flat.

The transformer is magnetically shielded in a permalloy case, which in turn is inserted into a robust 10mm thick aluminum cylinder bored out of a solid aluminum block. Together with the heavy metal case the transformer effectively isolates against environmental noise.

The stability of the transformer is superb thanks to its substantial weight of 2kg

Equipped with XLR terminal for full balance connectivity as well as common RCA plug terminal.

The ST-90 will be a perfect match to most high quality MC cartridges, such as the Cadenza series, the MC A90, the MC Windfeld, the Ortofon Xpression, MC Anna, MC A95 as well as the SPU cartridges.


  • Frequency response: 10 ~ 100kHz (+ 0dB-2.5dB)
  • Step-up ratio: 24dB (47kΩ / 1kHz)
  • Compatible Cartridge Impedance: 2Ω ~ 60Ω
  • Load Impedance: 47kΩ or more


We have played Teresa Teng’s 5th Anniversary record (Polydor 1983 2LP version) and Joan Baez’s  Diamonds & Rust LP countless times in our audition room but we have never heard anything so captivate, so intoxicated; We almost forget the existence of sound system all together.

Without any changes to turntable tonearm, cartridge, pre-amplifier, power amplifier and speakers, we installed Ortofon ST-90 Step Up Transformer before Zesto Andros PS1 phono stage. The effect is tremendous especially for mesmerizing vocal details and the depth of the music, as well as airiness of high frequencies.

Simple marvelous and amazing!

hifishuo.com (Oct 12, 2015)
* original review is in Chinese