STUDIO PROJECTS VTB-1 VALVE MIC.PREAMPLIFIER

The new Studio Projects VTB-1 is the ultimate in low cost mic preamplifier technology.
Incorporating true class A/B switching, the VTB-1 is a totally discrete circuit. Unique to
the VTB-1 is the "Tube Drive“. The Tube Drive is a variable drive to a 12AX7, that allows
the user to blend as little, or as much of the Tube Drive they want. This VTB-1 allows
the user the most flexibility of any mic preamplifier in it's price class.
The VTB-1 allows you to go from a pristine solid state sound, to any combination of Tube
Drive you choose...even hard distortion for guitars and bass! The VTB-1 is must have device
as the perfect mic preamplifier for any microphone!

Features

? 48 Volt Phantom Power
? Phase Reverse
? Variable Input Gain Control On Detented Pot
? 1/4" D.I. Jack On Front Panel
? High Pass Filter
? Descrete Solid State Class A/B Design
? TRS Insert
? Mic/Line Switch
? VariableTube Blend On Detented Pot
? Meter Read Select Between Input and Output level
? Switchable Impedance between 50/200 Ohm
? 5 position LED metering
? XLR mic input
? Balanced outputs on XLR and 1/4“
? External AC Power Supply For extreme Low Noise Operation
? Output Gain Control On Detented Pot

Applications

? A superb vocal mic pre with warm transparent character
? Great for use as a Tube DI Box
? Great for production, broadcast, and voice over work
? Perfect for the professional and home project studio
? A quality vocal mic preamplifier suitable for all vocal styles

• 1 microphone, XLR (bal.) or 6.3 mm jack (unbal.)
• Gain control, 10 steps (6-50 dB)
• Phantom power can be switched on
• Clip LED
• 1 line output, XLR (bal.) or 6.3 mm (unbal.)
• Operation via supplied power unit

Mic Inputs
• Frequency response at minimum gain (0dB): -0.35dB at 20Hz and –3dB at 122kHz
• Frequency response at maximum gain (60dB): –2.5dB at 20Hz and –3dB 103kHz
• Gain range: 0dB to +60dB in 10dB steps, plus 0dB to +20dB continuously variable trim
• Maximum headroom: +7.4dBu
• THD+N: 0.0009% (measured at 1kHz -20dBu input signal, at 30dB gain setting, with a 20Hz/22kHz bandpass filter)
• Noise EIN: -126dB (measured at 60dB of gain with 150Ω termination and 20Hz/22kHz bandpass filter)
• Noise at main output with unity gain: -98dBu (measured with a 20Hz/22kHz bandpass filter)
• SNR: 123dB (relative to max output 25dBu)
• SNR: 120dB (relative to 0dBFS (+22dBu)
• CMRR: 88dB.
• Input Impedance, variable: 600Ω, 1400Ω, 2400Ω, 6800Ω

Line Inputs
• Frequency Response at unity gain (0dB): -0.3dB at 20Hz and –3dB at 94kHz
• Gain range: -20dB to +10dB in 10dB steps, plus 0dB to +20dB continuously variable trim
• Maximum headroom: +25.4dBu
• THD+N: 0.002% (measured with +4dBu input signal, 0dB gain setting, with a 20Hz/22kHz bandpass filter)
• Noise at main output with unity gain: -91dBu (measured with a 20Hz/22kHz bandpass filter)
• SNR: 116dB (relative to max output 25dBu)
• SNR: 113dB (relative to 0dBFS +22dBu). Input Impedance: 10kΩ

Instrument Inputs
• Frequency Response at +10dB gain: -0.2dB at 20Hz and 0dB at 200kHz
• Frequency Response at +40dB gain: -3dB at 20Hz and –3dB at 38.4kHz
• Gain range: +10dB to +40dB continuously variable
• Maximum headroom: +11.5dBu
• THD+N: 0.006% (measured with –20dBu input signal, at minimum gain (+10dB), with a 20Hz/22kHz bandpass filter)
• Noise at main output with minimum gain (+10dB): -95dBu (measured with a 20Hz/22kHz bandpass filter)
• Input Impedance = >1MΩ

High Pass Filter
• Roll off = 18dB per octave 3 pole filter
• Frequency range: 16Hz to 420Hz (continuously variable, measured at the 3dB down point)

Meters
• 6 LED meter is calibrated 0dBFS = +22dBu (the maximum level which can be correctly converted by the optional internal A/D converter before overload occurs). The meter calibration points are as follows:

Meter panel calibration value in dBFS / Equivalent dBu value
0dBFS / +22dBu
-2dBFS / +20dBu
-6dBFS / +16dBu
-12dBFS / +10dBu
-18dBFS / +4dBu
-42dBFS / -20dBu



Front and rear connectivity

Analogue Channel Inputs (Inputs 1-4)
• 4 instrument 1⁄4” TS jack inputs on front panel
• 4 microphone XLR inputs on rear panel
• 4 line 1⁄4” TRS jacks on rear panel
• 4 insert return 1⁄4” TRS jacks on rear panel
• 4 ADC XLR inputs on rear panel

Analogue Audio Outputs (Outputs 1-4)
• 4 line XLR outputs on rear panel
• 4 insert send 1⁄4” TRS jacks on rear panel

Other I/O
• IEC power input connector 100Vac – 240Vac

Front Panel Indicators
• 8 output meters, 6 segment
• 4 30-60 mic gain range selection indicator
• 4 +48V phantom power indicator
• 4 Phase indicator
• 4 Insert In indicator
• 4 Filter In indicator
• 4 Input selection indicators (Mic, Line, Inst)
• 4 Z In microphone input impedance selection indicators (Low, ISA110, Med, High) Clock select indicators (44.1, 48, 88.2, 96, 176.4, 192)
• Ext clock indicators (Lock, Word clock, 256X)

Weight
5.5kg
12.2lbs

Dimensions (W x H x D)
480mm (W) x 88mm (H) x 280mm (D)
19" (W) x 3.5" (H) x 11" (D)

• • Ultra-high quality 8-channel A/D and D/A interface for virtually any digital recording/mixing environment
  • 8 state-of-the-art MIDAS designed Mic Preamplifiers
  • Phantom power on all microphone inputs
  • Reference-class Cirrus Logic 24-bit converters for ultimate signal integrity
  • Processes 48 and 44.1 kHz sample rates
  • External sample rate synchronization via word clock or ADAT input

• Optical ADAT in/out interface for ultimate compatibility
• All mic/line inputs routed to the ADAT output
• ADAT input routed to all Line outputs
• “Planet Earth" switching power supply for maximum flexibility (100 - 240 V~), noise-free audio, superior transient response plus low power consumption for energy saving
• High-quality components and exceptionally rugged construction ensure long life
• Conceived and designed by BEHRINGER Germany