The concept behind the Useful Arts BF-S Pro DI is simple. Useful Arts took the audio circuitry of the BF-1 and coupled it with the linear power supply from the SFP-60. The result? Astounding clarity, headroom and noise specs that only come with the nearly-noiseless high voltage that a linear power supply can deliver.

Most tube DIs start with the design philosophy of a guitar amp, not the BF-S. The BF-S is designed to complement the amp, while at the same time offering a different method of impedance conversion that delivers clarity and depth for recording.
 
DI recording is usually a bit of a bummer. Even with a really good DI, electric instruments sound lifeless at best, or tinny at worst. The BF-S sounds exuberant - adding just a touch of second harmonic to make the subjective listening experience compelling without sounding like the instrument has been altered in any way. Instruments just sound alive. Encased in a powder coated steel enclosure to withstand the rigors of daily use on a tracking room floor the BF-S has a noise floor of better than 70 dB. Almost unheard of for tube gear. With its heavy-duty linear power supply, the BF-S is flat from 15 Hz to 80 kHz (-2 dB)!