Marketing wise the Phono Loco is a disaster. There was a complete disregard for market acceptability. All design decisions were based on optimal engineering. It was all about performance possibilities. Marketing was thrown under the bus.
Unlike the other designs, the Phono Loco is totally focused as a specialized transimpedance unit. There is no concession to flexibility and options. With that clutter removed, the circuit can be refined and optimized to ONE goal. The Phono Loco does not hedge it’s bets. It is ALL on transimpedance.
The Phono Loco demands a balanced input signal. The circuit requires both connections from the cartridge coil to float with respect to ground. There was no bending around, or patching, or compromising to make it accept a single-ended signal.
Do not waste your money on expensive RCA to XLR adapters. Get the correctly balanced XLR cable from a good cable manufacturer. If you are not willing to get a balanced cable for the input connections, you should buy a more conventional phono preamp.