Audio Satori

Step Up Transformers

These step-up transformers are part of my reference collection, each offering unique characteristics tailored to different cartridge types and listening preferences. The phono gods have blessed me to have such a good selection of things.

Kondo CFz
  1. Primary Impedance: 1.5Ω (for 1Ω–10Ω cartridges), 30Ω (for 11Ω–40Ω cartridges)
  2. Step-Up Ratio: 34dB (1.5Ω), 20dB (30Ω)
  3. Load Impedance: 47kΩ (recommended)
  4. Dimensions: 126mm x 76mm x 163mm
  5. Weight: 2.7kg
  6. Output Cable: 1m KSL-VcII (copper cable) with RCA connectors

The CFz uses pure copper windings on a multi-layer permalloy core, double-shielded in copper and permalloy. This design aims to deliver a rich, natural sound with smooth tone and controlled dynamics. An excellent partner for the GE-1 phono stage.

Auditorium 23 Hommage T2
  • Design: Handcrafted in Germany by Keith Aschenbrenner
  • Impedance Compatibility: Designed for higher impedance cartridges like the Denon 103, EMT, and Shelter
  • Construction: Features a high-gain, low-primary-impedance transformer

One of the best boxes I have ever bought has been the Auditorium 23 Hommage T2 step up transformer. This is designed to optimise the performance of the EMT series of cartridges, as well as the venerable Denon DL103. The scale and texture that comes from using this step up transformer is hard to describe. Keith Aschenbrenner has spent a lifetime experimenting and researching this stuff, allegedly dissecting Western Electric 618 transformers in the process, and it all culminated in this masterpiece.

Fonolab Veliferi
  • Inputs: Two inputs with MM Step-Up transformer
  • Features: Includes a Phase Equalizer and Demagnetization function
  • Design: Modular phono module

The Veliferi is designed for modern, technically precise performance, focusing on neutrality and wide bandwidth. It aims to reveal microdynamics and transient detail with clarity and speed, while keeping distortion low. Lots of cool adjustability makes it handy for fiddling around and playing with different cartridges. The Phase Equaliser is an interesting feature too.

Fonolab Eqves Mannvs

Specialised broadband Step-Up transformer with 1:2 ratio specially designed for MM/MI phono cartridges.

  • Input Impedance: 1000 Ohms (primary)
  • Output Impedance: 4k Ohms
  • Frequency Response: 10Hz to 100kHz (+-1.0dB)
  • Ratio: 1:36 / 1:10

The Mannvs is designed specifically for MM and MI cartridges, providing a precise, lean, and clear presentation. It aims to highlight detail and texture, catering to listeners who value clarity and definition.
EQVES MANNVS gently raises the voltage of your cartridge to optimal values.
Many MM cartridges have relatively low output voltages (1.5-3.0mV), which when connected to a fixed-gain / low gain phono stage makes it impossible to get the most out of your favorite MM cartridge. With a MANNVS Step-Up transformer, you not only get quality high voltage from the MM cartridge at the input of the phono stage, but also reduce the overall noise level at the output of the phono stage.

Dynavector DV-6x
  • Impedance Compatibility: 3–40Ω
  • Load Resistance: 47kΩ
  • Step-Up Ratio: Not specified

The DV-6x is compact and well-engineered, pairing especially well with Dynavector’s own low-output moving coils. It offers a clean, open sound with balanced tonal character and good rhythm. This is sort of surplus to requirements these days, it may get added to my for sale page.

Supex SDT-77
  • Impedance Compatibility: 3–10Ω
  • Load Impedance: Not specified
  • Design: Vintage MC step-up transformer

The SDT-77 is a vintage design known for its warm and full sound. It features slightly rounded treble and strong midrange, making it musical and easy to listen to. I don’t really need it now, given I have the Kondo for low impedance cartridges, but I will keep it as a pair with the SD900/Super cartridge.

Aurorasound AFE-10 MM Expander
  • Adjustable Resistance: Six options (47, 23, 15, 6.8, 3.6, and 0.9 kΩ)
  • Adjustable Capacitance: Six options (0, 47, 100, 220, 330, and 470 pF)
  • Mono/Stereo Switch: Included
  • Dimensions: 111mm x 120mm x 35mm
  • Weight: 398g

The AFE-10 is designed for high-output cartridges, offering adjustable load impedance and capacitance to optimize performance. It also includes a mono/stereo switch, providing flexibility for various setups.