ART TUBE MP Studio Microphone Preamp with VU Metering and OPL User Guide

ART TUBE MP Studio Microphone Preamp with VU Metering and OPL

ART TUBE MP STUDIO

Product Information

The ART TUBE MP Studio is a hybrid solid state and tube preamplifier that offers professional-caliber tube preamplification in a compact and flexible package. It features an output protection limiter (OPL) to precisely control output peaks and analog VU metering to aid in setting and maintaining proper signal levels.
The Tube MP Studio can be used in a wide variety of applications including recording, project and home studios, and as a direct box for instrument or line-level sources.

Features

• Hybrid solid state and tube circuit design
• Output protection limiter (OPL)
• Analog VU metering
• Compact and lightweight all-steel enclosure
• External power supply designed to operate at 115 VAC @ 50 to 60 Hz

Specifications

• Frequency Response: 10 Hz – 20 kHz (+0, -1 dB)
• Dynamic Range: >100 dB (20 Hz – 20 kHz)
• Equivalent Input Noise: -129 dBu (‘A’ weighted XLR to XLR)
• Maximum Input Level: +14 dBu (XLR), +22 dBu (TRS)
• Maximum Output Level: +28 dBu (XLR), +22 dBu (TRS)
• Total Harmonic Distortion: <0.05% (typical)

Product Usage Instructions

Installation

The Tube MP Studio is compact and lightweight, so mounting location is not critical. However, for greater reliability, it is recommended that you not place the Tube MP Studio on top of power amps or other sources of heat. The tube circuitry needs about a minute to warm up from a cold power up.

AC Power Hookup

Connect the external power supply to the Tube MP Studio and plug it into a standard electrical outlet. Only use the adapter that came with the Tube MP Studio. If the adapter becomes lost or damaged, contact ART Customer Service for replacement. If you need to purchase one locally, just make sure that you specify 9 Volt AC (not DC), at 800 ma.

Audio Connections

Connect your microphone or instrument to the appropriate input (XLR or TRS) on the Tube MP Studio. Use the gain control to adjust the input level. Connect the output (XLR or TRS) to your recorder or mixer.

Safety Precautions

To avoid the risk of shock or fire, do not expose this unit to moisture. Refer all servicing to qualified personnel. Do not remove the metal cover; there are no user-serviceable parts inside. Only use the power adapter that came with this unit or one obtained from ART’s Customer Service Department.

Warranty Information

The Tube MP Studio comes with a limited warranty. For more information, refer to the user manual.

INTRODUCTION

Thank you for purchasing the Tube MP Studio – and congratulations: You now own one of the most versatile preamplifiers available. Offering a superb level of sound quality, the Tube MP Studio’s hybrid solid state and tube circuit design combined with a straightforward user interface quickly and easily gives you access to all of its features.
The original ART Tube MP put professional-caliber tube preamplification into the hands of thousands of musicians and recordists that wanted great tube tone in a compact and flexible package.
The Tube MP Studio extends the range of applications by adding an output protection limiter (OPL) to precisely control output peaks, and analog VU metering to aid in setting and maintaining proper signal levels.
The Tube MP Studio can be used in a wide variety of applications including recording, project and home studios, where its metering functionality and OPL circuitry really shines. It also functions as a direct box, with impedance matching and preamplification for instrument or line-level sources.

PRODUCT FEATURES

• Built-in analog VU metering
• Built-in OPL (switch selectable)
• Over 60dB of gain
• Hand selected 12AX7A dual triode tube
• Balanced XLR inputs and outputs
• ¼” High impedance Instrument input and ¼” line level output
• +48V Phantom power (switch selectable)
• Phase Reverse Switch
• Gain (+20dB) Switch
• Input Gain Control
• Output Level Control
• Multifunction, dual color LED Power/Clip/Limit indicator
• Fully shielded all steel chassis
• Designed and developed in the USA

INSTALLATION

The Tube MP Studio may be used in a wide variety of applications and environments. Self-contained in an all-steel enclosure, the Tube MP Studio is designed for continuous professional use. Because the unit is compact and lightweight, mounting location is not critical. However, for greater reliability we recommend that you not place the Tube MP Studio on top of power amps or other sources of heat. The tube circuitry needs about a minute to “warm up” from a cold power up.

AC POWER HOOKUP
The Tube MP Studio has an external power supply designed to operate at 115 VAC @ 50 to 60 Hz. Units manufactured for use outside the United States of America have been modified to comply with the required electrical specifications. Only use the adapter that came with the Tube MP Studio. If the adapter becomes lost or damaged, contact ART Customer Service for replacement. If you need to purchase one locally, just make sure that you specify 9 Volt AC (not DC), at 800 ma.

AUDIO CONNECTIONS
Audio connections to and from the Tube MP Studio are balanced XLR (Pin 2 = Hot (+), Pin 3 = Cold (-), Pin 1 = Ground) and unbalanced ¼” (Tip = Hot (+), Sleeve = Ground). We recommend that you switch off the +48V Phantom Power whenever changing connections to the XLR input.

SAFETY PRECAUTIONS

Warning: To avoid the risk of shock or fire, do not expose this unit to moisture. Refer all servicing to qualified personnel. Do not remove the metal cover; there are no user-serviceable parts inside. Only use the power adapter that came with this unit or one obtained from ART’s Customer Service Department.

CONTROLS & INDICATORS

INPUT CONTROL
The Input Control sets the amount of input gain of the Tube MP Studio. Turn the control clockwise to increase gain and counterclockwise to decrease gain. You may control two ranges of gain with this control, +26 to +60dB and +6 to +40dB. Selection of the gain range is made with the +20dB gain switch.

+20DB GAIN SWITCH
Use the +20dB Gain Switch to set the gain range of the input control. When the switch is out, the Tube MP Studio operates in Normal mode. Depressing the switch adds 20dB of gain. This mode is indicated by the labeling in red and corresponds directly to the input control’s red gain range labeling. For microphone applications, where more gain is needed, push the switch in. For hot line level inputs, set the switch in the out position.

PHANTOM POWER +48V SWITCH
The Tube MP Studio can power any microphone needing +48 volts DC Phantom power. Phantom power is supplied to pins 2 and 3 of the XLR Input jack when this switch is depressed. The Tube MP Studio slowly applies and removes the +48volts, to prevent damage to microphones.
Be sure to turn down or mute the output of the Tube MP Studio when engaging or disengaging Phantom power. Additionally, when disengaging, allow 30 to 45 seconds for the power to completely discharge. Most microphones will make a sound like air leaking from a tire when Phantom power is disconnected, but some can make some very nasty low rumbles and whines as well.

Dynamic microphones should not be affected or damaged if they are plugged into a line where Phantom power is present. However, if the mic doesn’t need it, do not use it. Some things are best left untested!

PHASE REVERSE SWITCH
The Phase Reverse switch is provided to reverse the phase of the signal. This switch works on Pins 2 and 3 of the XLR output jack and also reverses the polarity of the ¼” output jack. In the Normal position, the signal is in- phase. In the Reverse (or “in”) position, Pins 2 and 3 are reversed and the signal is changed to 180 degrees out of phase.

In multiple microphone applications, mic placement can affect the phase of the signals. If two microphones pick up the same signal from different locations, the result can be a hollow or frequency “shifted” sound. In some cases it may sound as if an instrument disappears if it happens to be 180 degrees out of phase. Depressing the Phase switch can remedy this. In general, if your sound is “thin” or “out of position”, try reversing the phase to correct the problem.

OPL (PEAK LIMITER) SWITCH
Depressing this switch engages the OPL (Output Protection Limiter) circuitry. This circuit precisely and accurately controls the output peak signal level. This FET (field effect transistor) peak limiter has a fast attack for peaks and slow release time. This helps you to prevent clipping or overload of equipment that follows the Tube MP Studio, such as the A/D converters on a sound card or digital recorder, in-ear monitor systems, or live monitoring system. When engaged, the output signal is limited to approximately 0dBu at the ¼” output jack and +6dBu at the XLR output jack, with the Output control all the way up. The VU Meter and LED indicator reflect the OPL circuit’s action.

POWER/CLIP/LIMIT LED
The bi-color Power/Clip/Limit LED lights green after power is applied and with lower level signals. If OPL is not being used, then the LED will serve as a signal clip indicator. It will light red whenever the signal at the tube’s output is about to clip. If the LED is constantly lit, reduce the signal level with the Input gain control, or Activate the OPL circuitry.
When the OPL circuit is engaged, the LED will turn red whenever the output signal peaks exceed the limiter’s threshold, at which point the limiter will reduce gain automatically, to prevent output clipping.

VU METER
The VU Meter gives an analog representation of the Tube MP Studio’s output signal level. “0dB” on the meter represents +6dBu at the ¼” output jack and +12dBu at the XLR output jack. Besides showing the average analog level, it is sensitive to attack transients. When not using OPL, the VU Meter is a great indicator of how hard you are running the tube. It also helps in setting a consistent level as you change mics and instrument sources.
The VU Meter also reflects the impact of the OPL circuitry on the signal. For example, if the signal is “in the red” on the meter, the meter will reflect the attenuation of the signal when the OPL is activated, and the signal is brought out of the “red” .

OUTPUT CONTROL
The Output Control sets the output level of the Tube MP Studio. When the control is fully counterclockwise, there is no output. Turning the control clockwise increases the level of the output signal. When setting the Output level control, refer to the VU Meter for an accurate level leaving the Tube MP Studio.

CONNECTIONS

Despite the Tube MP Studio’s sophistication, it is easy to interface the unit with a wide variety of equipment. All inputs and outputs, are located on the rear panel. Standard ¼” and XLR inputs and outputs make patching simple.

¼” INPUT JACK
The ¼” Input jack is for instrument and line level inputs. It has a high input impedance to minimize any loading effects on instrument pickups. It can also handle up to +22 dBu signals for line level signals.
Though not normally suggested, both input jacks can be used simultaneously, in a pinch, to sum two signals. The signal present at the XLR jack will tend to attenuate the signal of the ¼” input.

XLR INPUT JACK
The XLR Input jack is primarily intended for microphone input, and as such can furnish Phantom Power when needed. It can handle up to +14 dBu signals, which is the hottest signal you would get out of any microphone. For even hotter input signals, you should use the ¼” input jack. The XLR Input jacks medium input impedance is extremely flat over a wide frequency range, which allows it to be musically neutral to virtually any microphone (one of the Tube MP’s lesser known secrets).

XLR OUTPUT JACK
The XLR Output jack of the Tube MP Studio is active balanced. You may use it in an unbalanced configuration without harm to the output circuitry. The XLR output can provide a hefty signal level (+28dBu) at a low impedance, so make sure that you do not overdrive equipment with sensitive inputs. When using it on the front end of a mixer, go into the mixer’s line in or insert inputs and not necessarily into the mixer’s microphone input, unless the mixer can pad that input’s level.

¼” OUTPUT JACK
The ¼” Output jack is unbalanced and should be used for sending signals to amps, processors, or other unbalanced configurations.
Both balanced and unbalanced output connections may be used simultaneously. This is particularly useful when using the Tube MP Studio as a direct box for instruments or line level signals. Make sure that both pieces of equipment connected to the Tube MP Studio’s outputs are connected to the same earth ground, beforehand, to avoid electrical shock.
If you experience a grounding hum when using both output connectors (one to a console, one to an instrument amp) simultaneously, a ground loop may be the problem. To remedy this problem, disconnect the ground wire (pin 1) from the XLR cable plugged into the Tube MP Studio’s output. This interrupts the ground path and therefore breaks the loop.

POWER JACK
An external 9 Volt AC adapter powers the Tube MP Studio. Plug the adapter into the PWR jack and then into a power outlet. Only use the adapter that came with the Tube MP Studio. If the adapter ever becomes damaged, immediately discontinue use. They can be purchased locally or directly from ART. Just make sure that you specify 9 Volt AC (not DC), at 800 ma.

Fill in the following information for your reference:
Date of purchase
Purchased from
SERIAL NUMBER

OPERATION

The main application of the Tube MP Studio is a microphone preamplifier. Plug any microphone directly into either input and set the input and output controls to provide an appropriate level into the next stage of your system.
Use the Tube MP Studio as an acoustic or piezo pickup preamplifier to run directly into a console, amp, processor, recorder, or sound card.
The Tube MP Studio is ideal for use as a DI box. Plug the instrument into either input and use the XLR or ¼” (or both) outputs to connect to your recorder, board or PA system.

Because of its low noise and excellent tonal qualities, the Tube MP Studio is ideal for running mixes through before recording to DAT or cassette. Used as a mastering device, the Tube MP Studio is capable of adding warmth and gentle tube compression to the signal. Variable Input and Output level controls make the Tube MP Studio ideal for level matching material in postproduction situations.

WARRANTY INFORMATION

Limited Warranty
Applied Research and Technology will provide warranty and service for this unit in accordance with the following warrants:
Applied Research and Technology, (A R T) warrants to the original purchaser that this product and the components thereof will be free from defects in workmanship and materials for a period of three years from the date of purchase. Applied Research and Technology will, without charge, repair or replace, at its option, defective product or component parts upon prepaid delivery to the factory service department or authorized service center, accompanied by proof of purchase date in the form of a valid sales receipt.

Exclusions:
This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs. This warranty is void if the serial number is altered, defaced, or removed.
A R T reserves the right to make changes in design or make additions to or improvements upon this product without any obligation to install the same on products previously manufactured.
A R T shall not be liable for any consequential damages, including without limitation damages resulting from loss of use. Some states do not allow limitations of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific rights and you may have other rights, which vary, from state to state.
For units purchased outside the United States, an authorized distributor of Applied Research and Technology will provide service.

SERVICE

The following information is provided in the unlikely event that your unit requires service.

1. Be sure that the unit is the cause of the problem. Check to make sure the unit has the proper power supplied, all cables are connected correctly, and the cables themselves are in working condition. You may want to consult with your dealer for assistance in troubleshooting or testing your particular configuration.
2. If you believe the ART unit is at fault, go to www.artproaudio.com. You may contact Customer Service for more assistance, or directly request a Return Authorization for service in the “resources” area of the website.
3. If you are returning the unit for service, pack the unit in its original carton or a reasonable substitute. The original packaging may not be suitable as a shipping carton, so consider putting the packaged unit in another box for shipping. Print the RA number clearly on the outside of the shipping box.
4. Include, with your unit, a note with the RA number and your contact information including a daytime phone number, preferably attached to the top of the unit.

Fill in the following information for your reference:
Date of purchase:
Purchased from:
Serial Number:

TUBE MP STUDIO SPECIFICATIONS

• Dimensions 5.0”H x 5.5” W x 2.0”H
• Weight 1.5 lbs.
• Input Connections XLR (balanced), ¼”TS
• Output Connections XLR (balanced), ¼”TS
• Input Impedance XLR, ¼” 2K ohms, 840k ohms
• Output Impedance XLR, ¼” 600 ohms, 300ohms
• Maximum Input Level, XLR +14dBu
• Maximum Input Level, ¼” +22dBu
• Maximum Output Level, XLR +28dBu
• Maximum Output Level, ¼” +22dBu
• CMRR >75dB (typical @ 1kHz)
• Frequency Response 10Hz to 30kHz, +/-.5dB
• Dynamic Range >100dB (20-20kHz) typical
• Total Harmonic Distortion (THD) <0.1% (typical)
• Maximum Gain
  • XLR to XLR 60dB (typical)
  • ¼” to ¼” 44dB (typical)
  • XLR to ¼” 54dB (typical)
  • ¼” to XLR 50dB (typical)
• Equivalent Input Noise (EIN)
  • XLR to XLR -129dBu (A-weighted)
  • ¼” to ¼” -105dBu (A-weighted)
• Tube Type 12AX7A, Dual Triode, Hand Selected
• Power Requirements USA – 9VAC @ .8A (typ.) Export units configured for country of destination

ART maintains a policy of constant product improvement. ART reserves the right to make changes in design or make additions to or improvements upon this product without any obligation to install same on products previously manufactured. Therefore, specifications are subject to change without notice.

Internet http://www.artproaudio.com
E-mail: support@artproaudio.com

TUBE MP STUDIO Tube Microphone Preamp with VU metering and OPL

©2000 Applied Research & Technology

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