Pro-Ject MC Step Up Box DS3 B

A transformer step-up for MC cartridges, dual mono and balanced, fitted with Lundahl LL1678 transformers: it raises the signal by 24 or 30 dB ahead of the phono stage's MM input.

MC Step Up Box DS3 B: how it works

This step-up box goes between the turntable and an MM phono stage: it is a passive device that raises the voltage of MC cartridges through Lundahl LL1678 audio transformers in a dual mono arrangement, which the Italian distributor lists as shielded in mu-metal. With no amplifying stage involved, noise and distortion stay very low; Pro-Ject recommends this route, paired with a good MM phono preamplifier and a valve one in particular, as the alternative to an MC phono stage.

Inputs and outputs are duplicated, single-ended RCA and balanced XLR, and are selected by front-panel push buttons; the balanced link cuts down the interference a cable collects. Gain is also chosen on the front, 24 or 30 dB, corresponding to transformation ratios of 1:16 and 1:32, while a button on the rear adapts the unit to the cartridge's impedance. Downstream Pro-Ject recommends a load of 47 kohms and 100 pF, in other words that of an ordinary MM input.

Specifications

• Type: passive transformer step-up for MC cartridges
• Transformers: Lundahl LL1678
• Transformation ratio: 1:16 or 1:32
• Gain: 24 or 30 dB, selected on the front panel
• Frequency response: 10 Hz to 55 kHz within ±1 dB
• Recommended load: 47 kohms and 100 pF
• MC inputs: one RCA pair, plus XLR
• Outputs: one RCA pair, plus XLR
• Dimensions: 206 x 79 x 197 mm (width, height, depth), 209 mm deep including sockets
• Weight: 1740 g
• Finishes: black, silver