Fonolab MANNVS II Phase Equalizer Equipped Step-Up Transformer for MM/MI

A 1:2 step-up transformer, balanced conversion, and phase equalizer combined into a single chassis

Could the MM/MI cartridge that I have been using really sound this good?
The MANNVS II is a composite MM/MI interface used between MM/MI cartridges and a phono equalizer. It integrates a 1:2 step-up transformer with wide-bandwidth, a phase equalizer that adjusts the unique phase characteristics of MM/MI cartridges, and XLR balanced output into a single chassis.

It does not simply increase output voltage, but also corrects the phase delay caused by the cartridge's inductance, optimizing phase coherence and frequency characteristics. It brings out the inherent information, spatial expression, and natural tonal quality of MM/MI cartridges.

Main Features of MANNVS II

Connect MM/MI Cartridges to High-End Systems with Balanced Connections

A major feature of the MANNVS II is that it balances the signal from an MM/MI cartridge via the transformer and can transmit it to a high-end phono system equipped with XLR balanced inputs.

By using a 2-conductor shielded cable for the XLR output, balanced transmission can be achieved, effectively reducing common-mode noise. Furthermore, galvanic isolation through a transformer suppresses ground loops and the influence of ground potential differences between connected devices.

The RCA output is an unbalanced connection using a standard single-conductor shielded cable. Although the galvanic isolation by the transformer also functions for the RCA output, when utilizing balanced transmission, the XLR output should be used. The RCA and XLR outputs are selected via the rear panel switch, and both terminals cannot be connected simultaneously.

Correcting phase lag unique to the cartridge

Since MM/MI cartridge coils have inductance, a phase lag occurs relative to the input signal. The MANNVS II is equipped with a selectable RL network that compensates for this phase lag caused by inductance.

By choosing settings appropriate for the cartridge, phase alignment is restored, and the frequency response is made flatter and more natural. Rather than actively emphasizing specific frequency ranges, it clarifies the contours of the sound image, localization, and spatial coherence while bringing out the cartridge's original tone and expressive capability.

Phase EQ to naturally adjust cartridge characteristics without altering the recording

The phase equalizer of the MANNVS II does not actively add tonal characteristics or effects to recordings. Its function is to correct phase lag caused by the inductance of MM/MI cartridges and to adjust phase characteristics and frequency balance toward a more natural state.

The effect varies depending on the cartridge and playback environment. According to the manufacturer, cartridges such as the Shure V15 tend to show noticeable changes, while designs like SoundSmith may display subtler differences. In combinations where phase and frequency characteristics are already favorable, adjustments may result in barely noticeable changes.

Adjustments are made by listening to the actual sound while turning the EQ knob to find the position where localization, sound cohesion, and frequency balance feel the most natural. If the EQ is not used, setting the switch to OFF will pass the signal directly through the built-in transformer to the output.

When EQ is enabled, the output level changes, so please lower the volume of the preamplifier or phono equalizer before switching it ON/OFF.

1:2 Wideband Transformer

The built-in wideband transformer has a step-up ratio of 1:2. It boosts the output voltage of MM/MI cartridges by approximately 6dB, making it easier to secure a sufficient signal level even when connected to a fixed-gain or relatively low-gain MM phono equalizer.

With a passive configuration that does not use power supplies or active amplification circuits, the delicate signals extracted from the cartridge are transmitted to the phono equalizer without adding new amplification circuits into the signal path.

Design to Minimize Noise Influence

Galvanic isolation through the transformer and EMI/RFI countermeasures suppress the effects of motor hum and ground potential differences, aiming for stable signal transmission.

By using the GND LIFT switch, the signal ground can be separated from the chassis ground. The effectiveness varies depending on the connection environment, so you can try both the normal connection and GND LIFT and select the setting with the least noise.

Design with European Aesthetic Sensibility

Each unit is carefully manufactured by skilled craftsmen in the Czech Republic. The appearance, designed by product designer Jan Snegov, combines a sturdy metal chassis with a distinctive operating knob, balancing modern functionality with a character reminiscent of classic analog equipment.