Version 1.1 October 2001 TUBE COMPOSER® www.behringer.
TUBE COMPOSER T1952 SAFETY INSTRUCTIONS CAUTION: To reduce the risk of electric shock, do not remove the cover (or back). No user serviceable parts inside; refer servicing to qualified personnel. WARNING: To reduce the risk of fire or electric shock, do not expose this appliance to rain or moisture. This symbol, wherever it appears, alerts you to the presence of uninsulated dangerous voltage inside the enclosurevoltage that may be sufficient to constitute a risk of shock.
TUBE COMPOSER T1952 FOREWORD Dear Customer, We thank you for expressing your confidence in BEHRINGER products by purchasing the BEHRINGER TUBE COMPOSER. It is one of my most pleasant tasks to write this preface, as our engineering team has made it possible to enhance the traditional tube circuitry design (particularly for our VINTAGER series of products), and adapt it to meet the high sound quality and dynamics requirements of modern, pro-level audio technology.
TUBE COMPOSER T1952 TUBE COMPOSER® Interactive Tube Dynamic Processor T1952 4
TUBE COMPOSER T1952 TABLE OF CONTENTS 1. INTRODUCTION .....................................................................................................................6 1.1 The concept .................................................................................................................................... 6 1.2 Before you get started ..................................................................................................................... 7 1.3 Control elements ...................
TUBE COMPOSER T1952 1. INTRODUCTION In purchasing the new TUBE COMPOSER T1952, you have acquired an extremely efficient and universal dynamics processor, which combines the precision of the solid state technology with the warmth and liveliness of tube technology. The most commonly used dynamic functions are all present. Every channel has its own independent compressor/limiter, an expander/gate and a peak limiter complemented by an extremely low-noise tube stage.
TUBE COMPOSER T1952 expander/gate section can be used as an independent unit to eradicate noise offering almost limitless possibilities within this application. IGC (Interactive Gain Control) peak limiter A further remarkable feature of the BEHRINGER TUBE COMPOSER is the IGC (Interactive Gain Control) limiter, an intelligent combination of a clipper and a program limiter. Above an adjustable threshold the peak limiter begins to function and restricts signal peaks radically (clipper).
TUBE COMPOSER T1952 1.3 Control elements Fig. 1.1: Front of the TUBE COMPOSER The BEHRINGER TUBE COMPOSER has two identical channels. Each channel is equipped with 7 toggle switches, 9 rotary controls, 6 LEDs and 2 VU meters. The CH 1 MASTER switch is for stereo operation: Fig. 1.2: Expander/gate- and compressor section 8 1 The TUBE COMPOSER converts to stereo mode by engaging the CH 1 MASTER switch, where the left channel assumes the control of both audio channels, i.e.
TUBE COMPOSER T1952 6 The THRESHOLD control sets the threshold point for the Compressor section. It has a range of -40 to +20 dB. The Soft Knee characteristic is applied to the signal exceeding the threshold point by a maximum of 10 dB. Above 10 dB, the signal would experience Hard Knee compression. The THRESHOLD LEDs show the actual state of the input signal relative to the THRESHOLD setting. The IKA-Soft Knee range is indicated by the middle yellow LED.
TUBE COMPOSER T1952 Fig. 1.3: Control elements of the peak limiter and tube sections 17 The VU METER can display three levels: the actual gain reduction of the compressor, the input or the output level. Gain reduction is displayed in a range of 1 to 30 dB, the input or output level is displayed in a range of -30 to +10 dB. The nominal level the display is switchable between -10 dBV or +4 dBu with the OPERATING LEVEL switch.
TUBE COMPOSER T1952 25 27 29 31 26 28 30 Fig. 1.4: Back panel of the TUBE COMPOSER 25 SERIAL NUMBER. Please complete and return the warranty card within 14 days of the date of purchase. Otherwise, you will lose your right to the extended warranty. Alternatively, you can register online at our website under www.behringer.com. 26 FUSE HOLDER / VOLTAGE SELECTION. Before connecting the T1952, confirm that the voltage display matches your local mains voltage.
TUBE COMPOSER T1952 2.1 Compression/levelling/limiting/clipping Now that the functions of the individual sections have been clearly explained, we would like to acquaint you with more terms and relationships of the dynamics process. Compression A compressor converts a large dynamic level into a restricted range. The extent of the resulting dynamic level is dependent on the threshold, attack, release and ratio settings.
TUBE COMPOSER T1952 Output Gain 0 dB Threshold IRC-Curve Expander, 1:8 Noise Gate, 1:oo Input Fig. 2.1: IRC curve characteristic of the expander The result is expansion, which is less critical to adjust and which is more tolerant of useable signals, whose level is slightly above that of the noise floor. Expansion therefore occurs extremely soft with low ratio settings, while the known negative effects of expansion are inaudible.
TUBE COMPOSER T1952 If the controls are set correctly, the drum sounds will be dry, sharp and clearly defined. If you do not have enough mics (or TUBE COMPOSER channels!) to record each instrument separately, try to create subgroups: put the snare and mid-toms together, and group the side-toms, bass drum and cymbals together with the help of a mixing console.
TUBE COMPOSER T1952 Control element IN/OUT switch SC EXT switch SC MON switch INTERACTIVE/HARD KNEE switch SC FILTER switch THRESHOLD control of the compressor section RATIO control AUTO switch OUTPUT control LIMITER control GAIN RED./LEVEL switch WARMTH control Setting IN OFF OFF INTERACTIVE OFF +20 dB 3:1 AUTO 0 dB OFF GAIN RED. COLD Tab. 2.
TUBE COMPOSER T1952 Peak Limiting Level Program Limiting Release Threshold Input Output 5 ms 10 20 approx. 1 s 20 ms t/ms 30 Fig. 2.3: IGC characteristic of the limiter section The diagram illustrates the functioning of the IGC limiter. The solid graph represents the output signal, while the dashed graph above shows the input signal response. The areas between the graphs represent the amount of gain reduction (bright areas are clipping areas, i.e.
TUBE COMPOSER T1952 2.6 The vacuum tube of the TUBE COMPOSER Our engineering team has made it possible to enhance the traditional tube circuitry (particularly for our TUBE COMPOSER) and adapt it to meet the high sound quality and dynamics requirements of modern, pro-level audio technology.
TUBE COMPOSER T1952 3.1.3 The TUBE COMPOSER in digital recording and sampling In an analog recording, too low recording levels lead to an increased noise level, whereas too high levels will cause a compressed and squashed sound. In extreme cases, it will cause distortion due to tape saturation.
TUBE COMPOSER T1952 as the last link in the chain preceding the power amp. Thus, you can effectively avoid damage to the midrange/ tweeter range caused by clipping of the high-energy bass signals. This statement, as paradoxical as it may seem at first, can be explained with the fact that especially low-frequency signals with high amplitudes can overload the power supply in the amplifier(s).
TUBE COMPOSER T1952 3.3 The TUBE COMPOSER as a sound effects unit In the early 1960s, musicians began looking at the recording process as a way to create new sounds. The pumping effect which had been avoided by earlier engineers suddenly became fashionable and was utilized as a creative tool, laying the groundwork for many of the sounds which are now considered indispensable in contemporary music.
TUBE COMPOSER T1952 3.6 Side chain 3.6.1 The TUBE COMPOSER as De-Esser De-essing is a special application of frequency selective compression. A problem often encountered in recording, is the sibilant (Ssss) sound of the human voice. High frequency, sibilant sounds and pops can produce very high energy levels which can sometimes cause an otherwise normal and undistorted voice to sound very harsh, shrill and sometimes unintelligible. The solution is frequency selective compression or limiting.
TUBE COMPOSER T1952 3.6.3 Suppressing instruments during recording Another function of the BEHRINGER TUBE COMPOSER allows helpful correction of previously recorded material. If, for example, an excessively loud bass drum needs to be suppressed, reduce all the equalizers frequency bands above 150 Hz. This setting causes frequency specific compression, which reacts as soon as increased energy is detected in this band.
TUBE COMPOSER T1952 Jet Engine 160 140 Sound-Pressure Level (dB SPL) Threshold Of Pain Power Drill 120 Machinery Hall 100 "Loud" Office 80 Normal Conversation 60 40 Quiet Apartment Recording Studio 20 Falling Leaves 0 Threshold Of Audibility Fig. 4.1: Dynamic range of human hearing The range of sound pressure levels or the dynamic range of human hearing encompasses a factor of 10,000,000.
TUBE COMPOSER T1952 frequencies are equally affected, we term this white noise. It is fairly obvious that electronics cannot function without components. Even if special low-noise components are used, a certain degree of basic noise cannot be avoided. This effect is similar when replaying a tape. The non-directional magnetic particles passing the replay head can also cause uncontrolled currents and voltages. The resulting sound of the various frequencies is heard as noise.
TUBE COMPOSER T1952 Fig. 4.3: The interactive relationship between the operating level and the headroom The need therefore arises for a fast acting automatic gain control system which will constantly monitor the signals and which will always adjust the gain to maximize the signal-to-noise ratio without incurring signal distortion. This device is called a compressor or limiter. 4.1.
TUBE COMPOSER T1952 level of noise, hum or other ambient background hiss, which can disturb the quality of the program material. Normally these noises are inaudible if the level of the desired signal lies significantly above the level of the noise. This perception by the ear is based on the masking effect: noise will be masked and thus becomes inaudible as soon as considerably louder sound signals in the same frequency band are added.
TUBE COMPOSER T1952 processing meant the beginning of a new era of recording media that provided plenty of dynamic response and allowed for loss-free copying of audio signals. As digital media were enhanced, however, many people began to miss the warmth, power and liveliness they knew from analog recordings. This is why purists still today consider digital recordings as sterile in sound. 4.
TUBE COMPOSER T1952 Fig. 4.6: Pentode In a triode the capacitance between grid and anode is a problem with regard to high frequencies and large amplification factors. For this reason, the pentode has a positively charged screen grid between the control grid and the anode. However, the positive charge of the screen grid attracts electrons emitted from the anode plate when it is hit by arriving electrons.
TUBE COMPOSER T1952 4.6 The best of both worlds Despite many efforts neither manufacturers nor developers have succeeded so far in simulating these positive properties of the tube by means of other devices. Additionally, the natural capabilities of the tube to act as a soft limiter can only be mimicked with highly sophisticated circuitry. Todays studio technology requirements are therefore met by a combination of both high-grade semiconductor and tube technologies.
TUBE COMPOSER T1952 dB 100 analog Mixing console Compact Disc Analog tape Analog records FM Radio 25 Video tape 50 Digital tape (16 Bit) 75 Fig. 4.8: Dynamic range of various media 5. INSTALLATION 5.1 Rack mounting The BEHRINGER TUBE COMPOSER fits into one standard 19" rack unit of space (3 1/2" / 89.5 mm). Please allow at least an additional 4" depth for the connectors on the back panel.
TUBE COMPOSER T1952 for trouble-free operation, even at high operating levels. Externally induced mains hum etc. will be effectively suppressed. The automatic servo-function recognizes the presence of unbalanced connectors and adjusts the nominal level internally to avoid level differences between the input and output signals (correction 6 dB). + Please ensure that only qualified persons install and operate the TUBE COMPOSER.
TUBE COMPOSER T1952 6. SPECIFICATIONS Audio input Connectors Type Impedance Nominal operating level Max. input level CMRR Audio output Connectors Type XLR and 1/4" TRS RF filtered, servo-balanced input 50 kOhm balanced, 25 kOhm unbalanced +4 dBu/-10 dBV switchable +21 dBu balanced and unbalanced typ. 40 dB, >55 dB @ 1 kHz Impedance Max.
TUBE COMPOSER T1952 Peak Limiter section Type Threshold Ratio Stage 1 limiter type Attack Release Stage 2 limiter type Attack Release Function switches SC extern SC mon Interactive Auto IGC (Interactive Gain Control) peak limiter variable (+4 dB to OFF (+22 dBu)) oo:1 Clipper zero zero program limiter program dependent, typ. < 5 ms program dependent, typ.
TUBE COMPOSER T1952 7. WARRANTY § 1 WARRANTY CARD/ONLINE REGISTRATION To be protected by the extended warranty, the buyer must complete and return the enclosed warranty card within 14 days of the date of purchase to BEHRINGER Spezielle Studiotechnik GmbH, in accordance with the conditions stipulated in § 3. Failure to return the card in due time (date as per postmark) will void any extended warranty claims.
