BF-S Pro DI – Tube Instrument Preamp/DI
The concept behind the BF-S is simple. Â We took the audio circuitry of the BF-1 and coupled it with the linear power supply from the SFP-60. Â The result? Â Astounding clarity, headroom and noise specs that only come with the nearly-noiseless high voltage that a linear power supply can deliver.
Which one is right for you? Â Both have identical feature sets and audio circuitry, except the BF-S adds a ground lift for its XLR output.
The BF-1 features a switching power supply, which is light, compact and convenient (no changes needed to adapt to any line voltage in any country).  It’s also convenient for live use and will fit in most guitar cases.  With its compact size, the BF-1 has a noise floor of about 60 dB.
With its heavy-duty linear power supply, the BF-S has a noise floor of better than 70 dB – almost unheard of for tube gear.  With this power supply, the BF-S is flat from 15Hz to 80 KHz (-2db)!  The BF-S weighs a good bit more than the BF-1, and we’ve encased the unit in a powder coated steel enclosure to withstand the rigors of daily use on a tracking room floor.
Most tube DIs start with the design philosophy of a guitar amp.  Not the BF-1 or BF-S. We assume that if you want a guitar or bass amp, you’ll buy one.  So we designed these two units to compliment 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.  We mean to change that.  The BF-1 and BF-S sound 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.
