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

Two channel classic Focusrite ISA transformer-based preamps Front panel, per channel:

• 1/4" instrument input
• Variable input impedance - Low, ISA 110, Medium, High
• Input selection - Mic, Line, Instrument
• 0 - 30 dB/30 - 60 dB gain switch
• Phantom power switch
• Phase invert switch
• 0 - 60 dB gain in 10 dB steps
• 0 - +20 dB continuously variable trim
• Variable high-pass filter with on/off switch
• Insert point on/off switch
• Eight-LED user-calibrated level meters
• Single power switch

• XLR-F mic inputs
• 1/4" TRS line inputs
• 1/4" TRS Sends
• 1/4" TRS Returns
• XLR-M line output
• Single peak meter calibration dial
• Single IEC power socket

Features
Superlative sound
Studio quality mic preamp
Total control - Input Gain, EQ contour, Output Gain,
Overload indicator
Multiple output connectors
XLR/jack combo input 
Switchable 48 V DC Phantom Power for condenser Mics
Compact, computer friendly package
Needs no external power supply
 
ARX is proud to introduce the e-pre - the ultimate microphone pre-amp for
hard disk recording, designed by audio professionals, not computer engineers.
The all-new e-pre is so much a part of your system that it fits right into a spare
5?" slot in your computer case! It's the perfect tool for all your day-to-day
recording requirements. No equipment racks to plug in, no masses of cabling to
connect - the e-pre is ready and waiting when you need it.
The e-pre is a studio quality microphone pre-amp using the same internal components
as high end mixing consoles, built into a compact, computer friendly package.
It has controls for:
Input Gain - fully variable from 10dB through to 60dB to suit all types of microphones,
plus switchable 48 V Phantom Power to enable condenser microphones to deliver
their best.
A Contour control for EQ sweetening, providing fast, easy access to a whole range
of useful EQ curves
Output level control - fully variable to match the e-pre's output to the input of the sound
card. From -10dB consumer cards through to +4dB for professional sound cards, the
e-pre can handle it.
Multiple output connectors match up with any kind of sound card, including mini jacks,
standard jack, RCA (phono) plugs, and even a connector to link to the internal CD ROM
audio input of your sound card (if fitted).
We've even fitted a 12 VDC input connector on the rear to enable the e-pre to run from an
external power supply if required (eg for use with notebook computers or stand-alone use).

Any way you look at it, the e-pre by ARX is the total professional microphone pre-amp for
all your hard disk recording needs

e-pre Benefits
Professional Balanced XLR mic input
True 48v phantom power
Runs into the Line input of ANY sound card - uses the card you've already paid for
High headroom = clean recordings
Smart EQ
Compatible with non-computer audio equipment
Professional performance and specs in a user friendly package
 

T E C H N I C A L  S P E C I F I C A T I O N S
Input Impedance
Mic 2 K Ohms Balanced; XLR type Pin 1 Audio Ground, Pin 2 +, Pin 3-
Line 25 K Ohms Balanced, ?" TRS jack Tip +, Ring , Sleeve Audio Ground
Phantom Power Voltage Switchable +48 V DC on XLR Pins 2 and 3
Max Input Level Mic +15 dB, Line +20 dB
Input Gain 10 dB Minimum, variable to 60 dB Maximum
Output Level -10 dB variable through 0 dB to +4 dB
Overload Indicator Measured at all Gain points throughout the circuitry
Output Noise -90 dB Unweighted, -97 dB 'A' weighted
(Measured with Gain nominal 20 dB, Output level -10 dB)
Frequency Response 20 - 20 KHz ± 0.25 dB
Distortion
100 Hz 0.0085%
1 KHz 0.008%
10 KHz 0.0083%
(Measured with Mic Gain 20 dB, Output 0 dB)
Power Requirements 12 V DC from either computer supply or external supply
(external power supply not included in e-pre package)
Size 148mmW x 42mmH x 150mm D (5?“W x 1?H x 6“D)
Weight Under 1 Kilo (2.2 lbs)
 

• • 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

The PRE-73 Mk2 is the first one-channel low-cost preamp on the market that is using a fully discrete signal path with three separate transformers for the balanced mic input, the line input and the output.

The circuit is very similar to the classical preamp section of the Neve 1073 pre/eq module with a corresponding sound character that is warm, punchy, sweet and musical.
This classical sound has been heard on countless recordings through the years and it is a versatile sound that works very well on most sound sources and in most genres.

The PRE-73 Mk2 has a maximum gain of 80 dB on the mic input and the gain range on the Line input is -20 to + 10 dB. There is also a high-impedance instrument input.

The PRE-73 Mk2 is perfect for almost any signal source, no matter if it's a microphone with a high or low sensitivity (like a passive ribbon mic), a syntheziser or sound module or an electric guitar or bass.

The input impedance of the microphone input can be switched between 300 and 1200 ohms, which makes it possible to affect the tone of most microphones. There is also phase switch and an simple 4-step LED signal level meter.

The output level control makes it possible to make fine gain adjustments and also to overload the main gain stage for more character and then lower the signal to a suitable level before the output stage.

The Mk2 update consists of:
- An unbalanced insert jack (nominal level about 18 dBu) added on the back panel for inserting units like the coming GAP EQ-73, a three band eq.
-  LED meter levels adjusted.
- 600 Ohm termination resistor and jumper added to power supply board (accessible from the inside of the unit).
- Revised Gain switch, turning the know clockwise now increase the gain.
- Reduced noise at high gains by a change to the power supply grounding scheme.

The PRE-73 MKIII is a one-channel vintage style microphone-, line- and instrument preamplifier. The signal path uses only discrete components like resistors, capacitors and transistors. The in- and output is transformer balanced, using two different transformers, each one optimized for its purpose. This is the way audio components were built before integrated circuits became available.

The circuit used in the PRE-73 MKIII is similar to the preamp section in the classical 1073 module with a corresponding sound character that is warm, punchy, sweet and musical. These classic characteristics have been heard on countless recordings through the years and it is a versatile sound that works very well on most sound sources and in most genres.
The essence of this sound is now available at a surprisingly low cost, making it available to nearly everyone.

Features  :

• Vintage Style electronics. No intergrated circuits in the signal path.

• Maximum gain in MIC mode is 80 dB, enough to handle passive ribbon mics with quiet sound sources.

• GAIN switch range 20 - 80 dB. GAIN/LINE mode switch, gain is reduced by 30 dB in LINE mode.

• Selectable two position high frequency AIR boost eq, 3 or 6 dB @ 30 kHz.

• Selectable 6 dB/octave two frequency high pass filter at around 40 (HP1) and 170 Hz (HP2).

• Tantalum capacitors in the signal path.

• Switchable impedance in MIC mode, 1200 or 300 Ohms, will change the tone of most mics. The input impedance in LINE mode is 10 kohm.

• Switchable phantom power and absolute phase.

• A high-impedance instrument input for any sound module, electric guitar or bass.

• A simple but effective 4-step LED output level meter.

• The output level control makes it possible to make fine gain adjustments and also to overload the main gain stage(s) for more character and then lower the signal to a suitable level before the output stage.

• Combo XLR/TRS input jack and separate output XLR and TRS jacks for flexible connections.

• Insert jack for inserting EQ´s and other units.

• Selectable 600 ohm output termination.

• The pcb is prepared for the Carnhill input transformer.

• External power supply to avoid interaction with the audio circuits and transformers.

• A solid build quality that will last many years of normal use.

The MKIII has the following new features compared to the MKII:

• Tantalum capacitors in the signal path.

• Selectable two position high frequency AIR boost eq, 3 or 6 dB @ 30 kHz.

• Selectable two frequency high pass filter, 6 dB/octave at 40 or 170Hz.

• The pcb is prepared for the Carnhill input transformer.

• Revised and less complicated GAIN switch with a separate switch for MIC/LINE selection.

• All GAIN settings can also be used in LINE mode .