Behringer Tube Ultragain T1953 User manual

TUBE ULTRAGAIN T1953
Version 1.2 December 2002
Users Manual
ENGLISH

2
TUBE ULTRAGAIN T1953
This symbo , wherever it appears, a erts
you to important operating and mainte-
nance instructions in the accompanying
iterature. Read the manua .
SAFETY INSTRUCTIONS
CAUTION: To reduce the risk of e ectric shock, do not remove
the cover (or back). No user serviceab e parts inside;
refer servicing to qua ified personne .
WARNING: To reduce the risk of fire or e ectric shock, do not
expose this app iance to rain or moisture.
DETAILED SAFETY INSTRUCTIONS:
A the safety and operation instructions shou d be read before the app iance is operated.
Retain Instructions:
The safety and operating instructions shou d be retained for future reference.
Heed Warnings:
A warnings on the app iance and in the operating instructions shou d be adhered to.
Follo instructions:
A operation and user instructions shou d be fo owed.
Water and Moisture:
The app iance shou d not be used near water (e.g. near a bathtub, washbow , kitchen sink, aundry tub, in a wet
basement, or near a swimming poo etc.).
Ventilation:
The app iance shou d be situated so that its ocation or position does not interfere with its proper venti ation.
For examp e, the app iance shou d not be situated on a bed, sofa, rug, or simi ar surface that may b ock the
venti ation openings, or p aced in a bui t-in insta ation, such as a bookcase or cabinet that may impede the
f ow of air through the venti ation openings.
Heat:
The app iance shou d be situated away from heat sources such as radiators, heat registers, stoves, or other
app iances (inc uding amp ifiers) that produce heat.
Po er Source:
The app iance shou d be connected to a power supp y on y of the type described in the operating instructions
or as marked on the app iance.
Grounding or Polarization:
Precautions shou d be taken so that the grounding or po arization means of an app iance is not defeated.
Po er-Cord Protection:
Power supp y cords shou d be routed so that they are not ike y to be wa ked on or pinched by items p aced
upon or against them, paying particu ar attention to cords and p ugs, convenience receptac es and the point
where they exit from the app iance.
Cleaning:
The app iance shou d be c eaned on y as recommended by the manufacturer.
Non-use Periods:
The power cord of the app iance shou d be unp ugged from the out et when eft unused for a ong period of time.
Debris and Liquid Entry:
Care shou d be taken that debris and/or iquids do not enter the enc osure through openings.
Damage Requiring Service:
The app iance shou d be serviced by qua ified service personne when:
- The power supp y cord or the p ug has been damaged; or
- Debris or iquid has entered the app iance; or
- The app iance has been exposed to rain; or
- The app iance does not appear to operate norma y or exhibits a marked change in performance; or
- The app iance has been dropped, or the enc osure damaged.
Servicing:
The user shou d not attempt to service the app iance beyond that which is described in the operating instruc-
tions. A other servicing shou d be referred to qua ified service personne .
This symbo , wherever it appears,
a erts you to the presence of
uninsu ated dangerous vo tage inside
the enc osurevo tage that may be
sufficient to constitute a risk of shock.

3
TUBE ULTRAGAIN T1953
FOREWORD
Dear Customer,
We thank you for expressing your confidence in BEHRINGER products by purchasing the BEHRINGER
TUBEULTRAGAIN. It is one of my most p easant tasks to write this preface, as our engineering team has
made it possib e to enhance the traditiona tube circuitry design (particu ar y for our VINTAGER series of
products), and adapt it to meet the high sound qua ity and dynamics requirements of modern, pro- eve audio
techno ogy. The fact that we are sti fascinated by antique tube radios and amps as we as the fine and warm
tona character that we usua y associate with them, are the reasons why vacuum tubes have kept their ground
even in state-of-the-art circuit topo ogies used especia y in professiona audio techno ogy or high-end devices.
We are particu ar y proud that we have found an extreme y effective symbiosis between so id-state and tube
techno ogies making them affordab e to anybody interested in audio techno ogy. As a ways, our top-priority
concern when deve oping this device was the demanding end user, in other words: you. It was our major goa
to meet your demands. Sure, it meant a ot of hard work to deve op such a product, but the fun has made it a
worthwhi e. The shine in the eyes of the many interested musicians at the Music Fair 1997, when they saw our
VINTAGER mode s for the first time, was a asting incentive driving our deve opment efforts.
It is our phi osophy to share our joy with you, because you are the most important member of the BEHRINGER
fami y. With your high y competent suggestions for new products youve great y contributed to shaping our
company and making it successfu . In return, we guarantee you uncompromising qua ity (manufactured under
ISO9000 certified management system) as we as exce ent technica and audio properties at an extreme y
favorab e price. A of this wi enab e you to fu y unfo d your creativity without being hampered by budget
constraints.
We are often asked how we can make it to produce such high-grade devices at such unbe ievab y ow prices.
The answer is quite simp e: its you, our customers! Many satisfied customers means arge sa es vo umes
enab ing us to get better conditions of purchase for components, etc. Isnt it on y fair to pass this benefit back
to you? Because we know that your success is our success, too!
I wou d ike to thank a peop e whose he p on Project TUBEULTRAGAIN has made it a possib e. Everybody
has made very persona contributions, starting from the designers of the unit via the many staff members in our
company to you, the user of BEHRINGER products.
My friends, its been worth the troub e!
Thank you very much,
U i Behringer

4
TUBE ULTRAGAIN T1953
T1953
TUBEULTRAGAIN
Tube Microphone/Line Preamplifier
sU tra ow-noise discrete microphone/ ine preamp ifier with se ected 12AX7 tubes
sULTRA-TUBE circuitry (UTC) adds desired amount of warmth without additiona noise
s Mic input stages are based on high qua ity, discrete conjugate transistor pair circuitry
s U tra-wide bandwidth from 18 Hz to 30 kHz for open sound
sWarmth contro a ows precise dosage of desired tube effect
sComp ete y versati e DI-Box due to servo-ba anced inputs and outputs
sLeve converter from -10 dBV to +4 dBu
sSoft mute +48 V phantom power to avoid switch-on thumps
sFu y tunab e and switchab e 12dB high-pass fi ter
sSwitchab e phase reverse to correct phase prob ems
sU tra ow-noise 4580 audio operationa amp ifiers offer outstanding sound performance
sHigh y accurate metering with true RMS eve detection
sServo-ba anced go d-p ated XLR and 1/4" TRS inputs and outputs
sHigh-qua ity detented potentiometers and switches with vintage-sty e knobs
sHuge back- it ana og VU meters and sty ish retro design
sBEHRINGERs high-performance OT-1 output transformer retrofitab e
sManufactured under ISO9000 certified management system

5
TUBE ULTRAGAIN T1953
TABLE OF CONTENTS
1. INTRODUCTION..................................................................................................................... 6
1.1 The concept .................................................................................................................................... 6
1.2 Before you get started ..................................................................................................................... 7
1.3 Contro e ements ............................................................................................................................. 7
2. OPERATION .......................................................................................................................... 10
3. APPLICATIONS ..................................................................................................................... 11
3.1 The TUBEULTRAGAIN as a microphone preamp ........................................................................... 11
3.2 The TUBEULTRAGAIN as a eve converter ................................................................................... 12
3.3 The TUBEULTRAGAIN as a direct injection box ........................................................................... 12
3.4 The TUBEULTRAGAIN as tube interface ...................................................................................... 12
4. TECHNICAL BACKGROUND .............................................................................................. 12
4.1 Audio dynamics ............................................................................................................................ 13
4.1.1 Noise as a physica phenomenon ....................................................................................... 13
4.1.2 What are audio dynamics? ................................................................................................. 14
4.2 The tubes used in the TUBEULTRAGAIN ..................................................................................... 15
4.3 Tube history .................................................................................................................................. 15
4.4 Design and functiona princip e of tubes ........................................................................................ 16
4.5 Properties of tubes ........................................................................................................................ 17
4.6 The best of both wor ds ................................................................................................................. 18
4.7 UTC circuit .................................................................................................................................... 18
4.8 Studio app ications ........................................................................................................................ 18
4.9 Phantom power ............................................................................................................................. 19
5. INSTALLATION ..................................................................................................................... 20
5.1 Rack mounting .............................................................................................................................. 20
5.2 Mains connection .......................................................................................................................... 20
5.3 Audio connections ........................................................................................................................ 21
5.4 Transformer-ba anced output (option) ............................................................................................ 21
6. SPECIFICATIONS ................................................................................................................. 22
7. WARRANTY ........................................................................................................................... 23

6
TUBE ULTRAGAIN T1953
1. INTRODUCTION
With the TUBEULTRAGAIN you have purchased an extreme y musica and f exib e microphone preamp ifier.
Our ULTRAGAIN range of devices has been a hit ever since we introduced our first mode some 5 years ago.
This high-end microphone preamp is based on many years of experience and findings in amp ifier techno ogy
and is used throughout the wor d in renowned studios, sound reinforcement systems as we as in broadcast
and te evision studios. Improving the egendary ULTRAGAIN even further was a rea cha enge, and we are
proud of our success. The BEHRINGER TUBEULTRAGAIN meets highest and no-compromise requirements
in terms of operation, sound, specifications and workmanship.
Even at the conception of the TUBEULTRAGAIN it was c ear that we had to combine the outstanding technica
specifications of our ULTRAGAIN with a warm tube sound. We are therefore proud to be ab e to present the
TUBE ULTRAGAIN, a device featuring our new y deve oped UTC vacuum tube circuit combined with a
no-compromise approach.
The heart of the TUBEULTRAGAIN is an extreme y ow-noise microphone preamp circuit that uses discrete
components to produce a high y transparent sound. In combination with our BEHRINGER tube techno ogy, the
operationa amp ifiers 4580 and a sophisticated circuit topo ogy, the TUBEULTRAGAIN yie ds exce ent noise
and distortion properties! The switchab e +48 V phantom power supp y a ows for connecting a most any kind
of microphone and suppresses power-up thumps with its soft mute function.
Our engineering team has made it possib e to enhance the traditiona tube circuitry (particu ar y for our
TUBEULTRAGAIN) and adapt it to meet the high sound qua ity and dynamics requirements of modern,
pro- eve audio techno ogy. The fact that we are sti fascinated by antique tube radios and amps as we as
the fine and warm tona character that we usua y associate with them, are the reasons why vacuum tubes
have kept their ground even in state-of-the-art circuit topo ogies used especia y in professiona audio
techno ogy or high-end devices. We are particu ar y proud that we have found a high y effective symbiosis
between so id-state and tube techno ogies making them affordab e to a most anybody in audio techno ogy.
With the exception of 2 12AX7/ECC83 tubes, the TUBEULTRAGAIN T1953 is based on SMD techno ogy
(Surface Mounted Device). These subminiature components known from aerospace app ications ensure both
extreme packing density and greater re iabi ity.
Speaking of re iabi ity: qua ity assurance p ays an ever important ro e in todays production methods. To
guarantee even greater operationa re iabi ity, our products are manufactured under one of the most stringent
industria qua ity assurance systems: ISO9000. This European certification is granted exc usive y to
companies whose manufacturing processes are in fu comp iance with this accurate standard.
1.1 The concept
The phi osophy behind BEHRINGER products guarantees a no-compromise circuit design and emp oys the
best choice of components. The op-amps, type 4580, used in the TUBEULTRAGAIN are chosen for their
superior signa -to-noise ratio, ow distortion and inear performance. Additiona y, the TUBE ULTRAGAIN uses
high qua ity resistors and capacitors with very tight to erances, high-grade switches as we other se ected
components.
The TUBEULTRAGAIN uses 12AX7 / ECC83 tubes. These triodes are capab e of hand ing a arge dynamic
range with itt e microphony. Add to this their re ative ruggedness and above average ife span and you can see
why its one of the most popu ar and re iab e pre-amp tubes on the market. These features a so ensure you
their avai abi ity for many years to come.
Balanced inputs and outputs
As standard, the BEHRINGER TUBE ULTRAGAIN is insta ed with e ectronica y servo-ba anced inputs and
outputs. The new circuit design features automatic hum and noise reduction for ba anced signa s and thus
a ows for troub e-free operation, even at high operating eve s. Externa y induced mains hum etc. wi be
effective y suppressed. The automatic servo-function recognizes the presence of unba anced connectors and
adjusts the nomina eve interna y to avoid eve differences between the input and output signa s
(correction 6dB).
Transformer-balanced outputs (optional)
In contrast to e ectronic ba ancing, the use of transformer-ba anced outputs offers the advantage of ga vanic
separation between units. E ectrica potentia differences and ground oops in audio insta ations do not
1. INTRODUCTION

7
TUBE ULTRAGAIN T1953
therefore impair the performance of the units. The transformer-ba anced outputs, common y used in radio and
TV engineering, can a so be fitted retrospective y upon request. The BEHRINGER transformer OT-1 is
designed to the highest exacting standards and is avai ab e as an accessory.
1.2 Before you get started
Your BEHRINGER TUBEULTRAGAIN was carefu y packed in the factory and the packaging was designed to
protect the unit from rough hand ing. Neverthe ess, we recommend that you carefu y examine the packaging
and its contents for any signs of physica damage, which may have occurred in transit.
+If the unit is damaged, please do not return it to us, but notify your dealer and the shipping
company immediately, other ise claims for damage or replacement may not be granted.
Shipping claims must be made by the consignee.
The BEHRINGER TUBEULTRAGAIN fits into two standard 19" rack units of space (3 1/2" / 89.5 mm). P ease
a ow at east an additiona 4" depth for the connectors on the back pane .
+Be sure that there is enough space around the unit for cooling and please do not place the
TUBEULTRAGAIN on high temperature devices such as po er amplifiers etc. to avoid
overheating.
The mains connection of the TUBEULTRAGAIN is made by using the supp ied cab e. It meets a of the
internationa safety certification requirements. P ease make sure that a units have a proper ground
connection.
+Before you connect your TUBEULTRAGAIN to the mains, please make sure that your local
voltage matches the voltage required by the unit!
As a standard the audio inputs and outputs on the BEHRINGER TUBEULTRAGAIN are fu y ba anced. If
possib e, connect the unit to other devices in a ba anced configuration to a ow for maximum interference
immunity. The automatic servo function detects unba anced connections and compensates the eve difference
automatica y (6dB correction).
1.3 Control elements
Fig. 1.1: Front panel of the TUBEULTRAGAIN
The front pane of the BEHRINGERTUBEULTRAGAIN consists of two identica channe s with four switches,
four rotary contro s and 4 ana og meters.
1. INTRODUCTION

8
TUBE ULTRAGAIN T1953
Fig. 1.2: Control element on the front panel
1Use the MIC/LINE switch to togg e between MIC and LINE modes. When the switch in up position, the
unit works in MIC mode (now you can activate the +48 V switch if required; in LINE mode this function
is disab ed). The new y deve oped UTC circuitry is active in both modes.
+Please note that the input phone jack is disabled in MIC mode, i.e. you must use the XLR
connector to access the microphone amp.
2This +48 V switch activates the +48 V phantom power circuit that uses the signa eads to supp y
condenser microphones with the required operating vo tage.
+Please check the connected signal source for matching specifications before you s itch
phantom po er on, so as to avoid damage to the microphone, etc.
3The CLIP LED signa s that a eve of at east +18dBu is present after the microphone amp stage. With
too high a eve the CLIP LED warns you to reduce the gain with the MIC TRIM contro , so as to avoid
distortion caused by over oading. During norma operation, the LED shou d not ight up at a .
4The MIC TRIM contro is enab ed in MIC mode on y and a ows for app ying gain from 10 to 60dB to the
input signa . In view of the extreme y high gain eve s that can be app ied, you shou d verify that the gain
contro is proper y set before you power up the unit. In case of doubt, set the contro fu y counter-
c ockwise, and start from there s ow y raising the gain. High gain settings and the resu ting eve s can
damage subsequent devices.
5With the PHASE REVERSE switch the input signa is reversed in phase by 180°. This function is
avai ab e both in MIC and LINE modes.
6When the high pass fi ter is in high position, the FREQUENCY contro defines the fi ters cut-off
frequency. With a setting range from 12 to 350Hz the fi ters main task is to e iminate bottom-end
rumb e noise, etc.
7The HIGH PASS switch activates/deactivates the fi ter.
1. INTRODUCTION

9
TUBE ULTRAGAIN T1953
Fig. 1.3: Tube ection of the TUBEULTRAGAIN
8Use the LEVEL contro to set the signa gain at the input of the tube stage. The gain can be set from
-20 to +20dB, i.e. the signa can be attenuated or amp ified by 20dB. When the contro is at its center
position, the eve is una tered. This contro is active in both MICROPHONE as we as LINE mode. Use
this contro to adapt the TUBE ULTRAGAIN to either home-recording eve (-10dBV) or professiona
eve (+4dBu). When this eve is too ow the tube effect becomes ess audib e and the signa -to-noise
ratio deteriorates.
9The PEAK LED above the LEVEL contro warns you of over oad of the unit. The LED shou d not ight up
during norma use. If the LED ights up frequent y, reduce the eve with the LEVEL contro to avoid distortion.
10 The VU meter disp ays the output eve if the TUBE ULTRAGAIN in a range from -20to +2dB. The 0dB
marker corresponds to the studio reference eve of +4dBu. Set the LEVEL contro so that the eve
meter just touches the red zone. A ways try to optimize the signa -to-noise ratio using this meter.
11 With the WARMTH contro you can set the amount of harmonics that are added to the origina signa .
This contro s the tube sound.
12 The WARMTH meter disp ays the amount of added harmonics. With this meter you can easi y reach an
optimum setting for the WARMTH contro .
13 With the POWER switch the TUBEULTRAGAIN is turned off and on. You shou d a ways make sure
that the POWER switch is in the Off position when initia y connecting the unit to the mains.
+Please note that the POWER s itch does not completely disconnect the device from the mains.
If the device is not in use for a long period of time, please disconnect it from the mains by
unplugging the po er cord from the po er socket.
15 17
1614
Fig 1.4: Back panel of the TUBE ULTRAGAIN
1. INTRODUCTION

10
TUBE ULTRAGAIN T1953
14 SERIAL NUMBER. P ease comp ete and return the warranty card within 14 days of the date of
purchase. Otherwise, you wi ose your right to the extended warranty. A ternative y, you can register
on ine at our website under www.behringer.com.
15 FUSE HOLDER / VOLTAGE SELECTION. Before connecting the T1953, confirm that the vo tage
disp ay matches your oca mains vo tage. When rep acing the fuse, you must a ways use the same
type. In many units the fuse ho der can be insta ed in one of two positions, a owing you to switch
between 230 V and 120 V. If you wish to operate a unit outside Europe at 120 V, then a stronger fuse
must be used (see chapter 6 SPECIFICATIONS). The mains connection is made via the IEC
receptac e. An appropriate mains cab e is inc uded.
16 AUDIO IN. These are the audio inputs of your TUBE ULTRAGAIN, avai ab e both as ba anced 1/4" TRS
and XLR connectors. The XLR connector is the common mic/ ine input. Both the XLR and the jack
connector accept unba anced as we as ba anced signa s. See chapter 5 INSTALLATION when wiring
unba anced.
17 AUDIO OUT. These are the audio outputs of your TUBEULTRAGAIN. Matching 1/4" TRS and XLR
connectors are wired in para e . The nomina eve is +4dBu. The maximum output eve is +16dBu.
2. OPERATION
Before you can use the BEHRINGER TUBEULTRAGAIN as a preamp, we recommend that you study the
various functions of the device. The high gain factors provided by the microphone preamp can produce extreme
eve s on the output side, which may damage subsequent devices. So, you shou d start with the fo owing basic
setting:
&RQWROHOHPHQW 6HWWLQ
J
+48 V switch OFF
MIC TRIM control 10 dB
MICROPHONE/LINE switch LINE
PHASE REVERSE switch OFF
HIGH PASS switch OFF
LEVEL control 0 dB
Tab. 2.1: Ba ic etup of the TUBEULTRAGAIN
Reduce the vo ume eve of the subsequent audio system to a minimum, and connect a microphone to the XLR
input connector on the BEHRINGER TUBEULTRAGAIN. Use either the 1/4" TRS or XLR output connectors to
connect the audio system. Owing to its output-side servo-ba ancing circuit, the TUBEULTRAGAIN detects
whether you use a ba anced or unba anced configuration and adjusts the eve interna y.
Now, power up the entire equipment and press the MIC/LINE switch upwards to activate the microphone
preamp. If you wish to use a condenser mic requiring +48 V phantom power, p ease press the +48 V switch.
+Please make sure that you are using an appropriate microphone before you s itch on the
+48 V supply. Read the operating instructions accompanying the microphone. Some condenser
mics might need another type of po er supply, older dynamic microphones could be
damaged by the +48 V voltage, and unbalanced microphones should never be operated in
combination ith a +48 V po er supply.
Configure the equipment according to the app ication on hand, speak into the microphone and turn the GAIN
contro c ockwise unti the 0dB LED ights up. If your DAT recorder, mixing conso e or other subsequent
devices have high-precision eve meters, you can use these to verify the correct eve setting.
The maximum output eve depends on the device that fo ows next in the audio chain, and must therefore be
set specifica y. The high-precision eve meter on the TUBEULTRAGAIN indicates the current operating eve .
The CLIP LED ights up at a eve of +18dBu signa ing that you have an additiona headroom of 5dB avai ab e,
before the microphone preamp starts over oading. If distortion/over oading occurs at high vo ume eve s, you
shou d reduce the gain with the MIC TRIM contro .
2. OPERATION