What distinguishes the Step Up Transformer – or SUP – from MK Analogue from the not really many other representatives of its genre that I have dealt with in more detail are its balanced outputs and inputs. Each channel offers no fewer than two of them: one with a 24-decibel boost and a 1-to-16 transfer ratio and one with a 30-decibel boost and a 1-to-32 ratio. Using two inputs per channel instead of one plus a switch reduces the number of solder joints between the cartridge and the windings and is supposed to improve sound quality. In addition to the six XLR jacks on the back of the SUT-1L, there are two RCA jacks that can accept resistor plugs to adjust the termination impedance. The resistors are in parallel with the transformer's primary windings, so they are merely reducing the load on which the cartridge is operating. Since the current generated by the cartridge no longer runs through the transformer, the volume of the analogue chain is slightly reduced by using the plugs. On the material of the transformer windings and the core, Matej Kelc does not provide any information on his website.

Matej Kelc places great emphasis on consistently shielding the transformer against electromagnetic interference, resonances and direct sound radiation. The transformer itself is located in a MU metal capsule, which is surrounded by a brass body lined with bitumen mats. The entire aluminum housing is not only lined with additional bitumen mats, but its base plate is also connected to a stainless-steel plate: the sandwich construction serves to further optimize the resonance behaviour. Sorbothane feet decouple the SUT-1L from the ground.

The matching MK Analogue phono stage goes by the self-explanatory name MM-PH-AMP and is therefore designed exclusively for amplifying signals of those strengths provided by moving magnet, moving iron or high-output moving coil pickups and MC transformers. The MM-PH-AMP features a dual-mono design and is powered by an external power supply, which, however, is not designed with separate channels. To achieve the greatest possible homogeneity of the channels, Matej Kelc relies on a common filtering of the voltage, partly performed in the external power supply and partly on the common main board. The total capacity is twice 23,500 microfarads. The passive circuitry comes up with four filter stages and also fulfils the function of an inrush current limiter. Separate voltage regulation for each amplifier section with high damping as close as possible to the load minimizes interference and enhances dynamics.

RIAA equalization is performed purely passively. Ultra-fast MKP film capacitors coated on both sides are used to guarantee extremely high resolution and dynamics. The amplification is assumed by operational amplifiers with a rise time of 150 volts per microsecond and a high bandwidth. The output stage is a class A power amplifier that, with appropriate cooling, is even capable of driving loudspeakers. Longer cables between the MM-PH-AMP and the preamplifier should therefore not pose a problem. Matej Kelc's goal in developing the phono stage was to achieve phase linearity in the audible frequency range. On his website, he explains this decision as follows: ‘The timely correct reproduction of all frequencies in the audible range determines whether a recording is perceived as lively, natural, dynamic, finely resolved, spatial and simply real. If this is the case, we not only listen to the music, we feel it, it moves us emotionally.’