Studio Projects VTB1 Variable Tube Microphone Preamp
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
Specifications:
- Maximum Gain : Mic In to Bal Out: 72dB (60dB preamp gain, 12dB output gain)
- Line In to Bal Out: 42dB (30dB preamp gain, 12dB output gain) Distortion/Noise
- (THD + Noise): -20dBu input-Mic; 0dBu input-Line Both measured at +15dBu output
- Mic or Line In to Bal or Line Out: <0.0015% (Blend set full CCW- no tube)
- Mic EIN: -128dBu (150 ohm source, 60dB gain)
- Frequency response
(20-20kHz, ref 1kHz): -20dBu input, +15dBu output - Mic In to Bal Out: +0 /-0.25 dB 0dBu input, +15dBu output
Line In to Bal Out: +0 /-0.5 dB - Phase response (20-20kHz, either input): <+/- 15 degrees
Input impedance: Mic Input (Rear switch in 200 ohm position): 2000 ohms
Mic Input (Rear switch in 50 ohm position): 300 ohms - Line Input (Front panel TRS jack): 1.5 meg ohms
- Output impedance: Male-XLR Balanced Output: 100 ohms (50 ohms each leg)
- TRS Line Out: 300 ohms (Impedance Balanced)
- Insert Jack (TRS): Nominal level approx 0dBu Located between SS preamp stage and tube/output stage
- Tip=Send: 50 ohms output impedance
- Ring=Return: 7500 ohms input impedance
