NFLU 325 rackmount service

This item is for rackmounting service only. Customer provides the transformers. XFO Audio provides chassis, engraving, switches, connectors and all wiring.

These are extremely popular transformers to use in a passive application like this for a good reason. They sound fantastic. Isolating grounds helps circuits perform their best. Even and odd harmonic saturation is pleasing to the ear. Sources often need a little something to make them sound larger than life, or at least as large as life. Coloration creates air in the high frequencies and a more cohesive, tighter feeling low end response.

RATIO: (3 Impedance ratio taps available)
This version of the XFO Audio NFLU 325 transformer box is the most elaborate implementation I have achieved so far. Mainly because it prvides you with all 3 ratio taps available at the turn of one 4 pole, 3 throw rotary switch. This means you can add a bit of free gain, pass through for coloration only without a boost or cut, or you can cleanly step down the output of your especially hot microphone preamps before you hit the inputs of the analog to digital converters in your interface. Ratios are 2:1, 1:1 and 1:2.

SPARKLE: (passive high-frequency boost)
Some, not all, transformers expect to feed a 600ohm input impedance, which is uncommon in most modern equipment. When the outputs feed a high impedance input, the transformer will create what is called high frequency "ringing". To get a flat response you can wire a 600 ohm resistor across the hot and cold pins of the output xlr. But what if you want some options? Not all or nothing?

This build features 5 termination resitor values strapped across the outputs to give you a range from a -1, a slight high frequency reduction, to +3, a full +4 dB boost at 20kHz. (+4dB might not sound like much, but at 20kHz, it is!) These options give you a simple, quick, perfectly recallable way to dial your sound in to the sweet spot for just the right amount of high frequency boost.