BF-S MkIII Tube Instrument Preamp/DI
Simply The Best Sounding Studio DI, Full Stop
Next-Level Studio DI
Useful Arts established a new standard for capturing the real sound of electric bass with the original BF-1 tube DI and the BF-S Pro. Now, the BF-S MkIII takes that legacy even further—offering exceptional sound quality, premium components, and features born from real-world artist feedback.
It’s everything you loved about the original, now upgraded for modern studios and pro players.
Features You’ll Love
- Ultra-high impedance input – Maintains the full character of your instrument
- Color Control – Adds pure, tube-generated second harmonics for added warmth
- All-tube 2-band EQ – Musical curves tuned by ear, not math
- Linear power supply – Ultra-quiet, high-voltage tube operation
- Brick-wall HPF – Cleans up rumble at 50 Hz
- Balanced XLR + TRS outputs – Studio-ready routing
- Thru jack + ground lift – Flexibility and isolation
- Effects loop – Connect stompboxes or rack gear
- Audiophile tone + tank-tough construction
Not Just for Bass
While the BF-S MkIII is beloved by bassists, its clean, audiophile-grade tube circuitry makes it a powerhouse for keyboards, guitars, and acoustic instruments with pickups. Even piezo pickups—famous for being hard to handle—sound rich and alive through the BF-S.
This is not an amp. It’s better. It makes everything sound real.
“Some boxes just make everything sound better. This is one of them. Not flashy—just tone magic.”
Peter Swann
Useful Arts Founder & Designer
Technical Specs
- Input Impedance: Ultra-high for true tone retention
- EQ: Tube-based 2-band, hand-tuned curves
- Color Control: Adds 2nd harmonic richness
- Outputs: XLR + TRS + Thru
- High-Pass Filter: 50 Hz brick-wall
- Effects Loop: Yes (Send/Return)
- Power Supply: Linear, ultra-low noise
- Noise Floor: Better than –70 dBu
- Build: Metal chassis, stage-tough