TUBE PAC PROFESSIONAL TUBE PREAMPLIFIER/COMPRESSOR USER’S GUIDE
TABLE OF CONTENTS Introduction Registration Features Overview Setting Up Unpacking AC Power Hookup Audio Connections Installation Safety Precautions Powering Up Front Panel Controls and Indicators Gain Control Gain Switch Phantom Power Switch Tube Drive/ Gain Reduction Display Threshold Control Slope Switch Speed Switch Phase Switch Output Level Control Bypass Switch Rear Panel Connections Power Switch Input Output Applications Tube Replacement Specifications On-line Information Warranty Information Service
Introduction Thank you for purchasing Applied Research and Technology’s Tube PAC. You’ve undoubtably noticed that the Tube PAC is as cool sounding as it looks. After getting familiar with the Tube PAC, you’ll realize what a great investment you’ve just made. The Tube PAC may be used everywhere! Anywhere you need level adjustments (gain or attenuation), and anywhere you need compression - you’ll be using the Tube PAC.
Features The Tube PAC is a unique product. It contains two independent award-winning circuit designs - one of the finest tube microphone preamplifiers available and one of the finest optical tube compressors available. Developed in partnership with studio and live sound engineers, the Tube PAC possesses a “sound” that is not available from any other product on the market - at any price! The Tube PAC was designed and constructed with the best components, assuring a lifetime of quiet, reliable performance.
OVERVIEW The Tube PAC (PreAmplifier/Compressor) is a multi-purpose tool for audio engineering and recording. Enclosed in a table-top (and 1/2 rack-able) chassis are two independent circuits featuring a tube-based analog preamplifier and a VCA-less, tube-based compressor with optical gain reduction control. Used as a mic/line preamp or as a DI (direct) box, the Tube PAC is designed to work seamlessly with any recording, sound-reinforcement, or electronic instrument setup.
pression without hearing the compressor. SETTING UP Unpacking Your Tube PAC was packed with care at the factory. The shipping carton was designed to protect it during initial shipment. Please retain this carton for use in transporting the Tube PAC, or in the unlikely event that you need to return your Tube PAC for servicing. AC Power Hookup The Tube PAC has an internal power supply designed to operate at 100 to 125VAC, 50 to 60Hz.
SAFETY PRECAUTIONS Warning: To avoid the risk of shock or fire, do not expose this unit to moisture. Do not remove metal panels from chassis parts. Removing the chassis from its cabinet parts exposes dangerous high voltages. There are no user-serviceable parts inside. Refer all servicing to qualified personnel. Note: If your power cord becomes damaged and must be replaced, always replace it with the proper type (3 prong.
to decrease gain. Selection of the gain range is made with the +20dB gain switch. You may control two ranges of gain with this control, +26 to +60dB and +6 to +40dB. When setting the Gain control, refer to the 4 segment Tube Drive Array for a visual reference to the Tube PAC’s internal signal levels (applied gain). Hint: the “sweet” spot for the Tube PAC is when the second warm LED in the Tube Drive array is lit. Gain Switch Use the Gain switch to set the range of the Gain control.
Tube Drive/Gain Reduction Display Four LEDs display how the tube gain is affecting the input signal. These LEDs are calibrated with the tube circuitry to give you an Note: these accurate representation of the tube’s output signal (N LEDs measure the signal level before the output level control). Use this meter as a visual for setting the Gain level. The first LED is labeled “Cln”. The tube is producing a clean output when this LED is lit. The next two LEDs are labeled “warm.
The easiest way to set the threshold control is to start with the control fully clockwise. After setting the Gain control, slowly turn the Threshold control counter-clockwise (lowering threshold) until you see the yellow (0dB) Threshold LED light. Now adjust the control (either lower or higher) until you have the amount of compression you desire. Use the Gain Reduction meter as a visual guide to the amount of compression applied.
switch also reverses the polarity of the 1/4” output jack. In the Normal (out) position, the signal is in-phase. In the Reverse (in) position, Pins 2 and 3 are reversed as the signal is changed to 180 degrees out of phase. In multiple microphone applications, the placement of the microphones can affect the phase of a signal. If two microphones pick up the same signal from different locations, the result can be a hollow or frequency “shifted” sound.
REAR PANEL CONNECTIONS Power The Power switch supplies and removes power from the unit. The Tube PAC should be turned “on” only when all monitor levels are turned down, or off, to protect against any “thumping” caused by high gain settings. Likewise, the Tube PAC should be turned “off” after turning all monitor levels down. Input and Output Connections The Tube PAC’s XLR connectors follow the AES standard: Pin 1 = Ground, Pin 2 = Hot (+), Pin 3 = Cold (-).
plugged into the Tube PAC’s output (or use a ground-lifted audio cable). This interrupts the ground path and therefore breaks the loop. APPLICATIONS The main application of the Tube PAC is as a microphone preamplifier and compressor. To use the Tube PAC as a mic or line preamplifier only, simply press the Bypass switch to bypass the compression circuitry. 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.
nect the XLR output jack of the Tube PAC to the XLR input of your mixer, however most affordable mixers do not allow you to bypass their internal preamp when using the XLR jack. You will cause no harm to either unit when doing this but you will probably experience slightly higher noise. This is due to the fact that you are now preamplifing your mixer’s preamp.
worse. The choice is yours. Please realize that unauthorized alterations to the Tube PAC will result in voiding the warranty. A R T Tube PAC SPECIFICATIONS Dimensions 5.25"D x 8.5"W x 1.65"H Weight 6.0 lbs Maximum Gain XLR to XLR 70dB 1/4” to 1/4” 67dB Phantom Power +48v DC (switchable) Compression Ratio 2.3:1 (comp)/ 6:1 (lim) Attack Time 6.5ms Release Time 200ms (fast), 70ms-1sec (auto) Equivalent Input Noise -129dBu (XLR to XLR, ‘A’ weighted) Dynamic Range >90dB (no weighting) Input Impedance 1.
WE’RE ON-LINE! For Product information, questions, applications, tips, answers and general discussion with A R T employees look for A R T on the Internet.. Look for the A R T folder on America Online in Craig Anderton’s Stage Studio and Sound (keyword “SSS”) under the Manufacturer Supported Forums. Email us at artroch@aol.com Look for the A R T supported area in the MIDI Forum B area on CompuServe (Go MIDI). CompuServe address: 76702,3700. Email us at artroch@cis.compuserve.
WARRANTY AND SERVICE INFORMATION Limited Warranty Warranty service for this unit will be provided by Applied Research and Technology, Inc. in accordance with the following warranty statement. Applied Research and Technology, Inc. (A R T) warrants to the original purchaser that this product is free from defects in workmanship and materials for a period of one year from the date of purchase.
5) Include with your unit: a return shipping address (we cannot ship to a P.O. Box), a copy of your purchase receipt, a daytime phone number and the description of the problem. 6) Ship the unit to: Applied Research and Technology, Inc. 215 Tremont Street Rochester, NY 14608 Atten: Repair Department R.A.# _______________ 7) Contact our Customer Service department at (716) 436-2720 for your Return Authorization number or questions regarding your repair.
