Features .......................................................................................................................................................... 4
AC Power Hookup ..................................................................................................................................... 5
Analog Audio Connections ........................................................................................................................ 5
Controls and Indicators .................................................................................................................................6
Input Control ............................................................................................................................................... 6
+20 dB Gain Switch ................................................................................................................................... 6
Input Impedance Control ........................................................................................................................... 6
Front Panel Controls (picture) ................................................................................................................... 7
Phantom Power +48V Switch .................................................................................................................... 7
V3 Variable Valve Voicing Control ......................................................................................................... 8
LED Input Meter ......................................................................................................................................... 8
VU Meter .................................................................................................................................................... 9
Output Control ............................................................................................................................................ 9
Digital Controls and Indicators .....................................................................................................................9
Digital Level Knobs..................................................................................................................................... 9
Digital Controls (picture) ......................................................................................................................... 10
Using V3 ....................................................................................................................................................... 16
Warranty Information ................................................................................................................................. 17
Service ......................................................................................................................................................... 18
Thank you for purchasing an ART DPS II (DI/O Preamp System II) - and
congratulations: You now own one of the most versatile preamplifiers available.
Offering a superb level of sound quality, the DPS II hybrid tube and solid state circuit
design, combined with a straightforward user interface, quickly and easily gives you
access to all of its features - and moves you forward into the digital recording domain.
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 ART DPS II is a tube microphone
preamplification system designed with recording musicians in mind. It has been
carefully designed, engineered and manufactured to provide you with years of great
sound and reliable service.
The DPS II extends the range of applications by adding V3 (Variable Valve
Voicing) which will help you to quickly and easily record a variety of instruments –
including drums, keyboards, acoustic and electric guitars, and more. We also feature
our OPL (Output Protection Limiter) to make V3 even more powerful. The DPS II
also functions as a direct box, with impedance matching and preamplification for
instrument or line-level sources.
A versatile insert loop on each channel provides access for additional signal
processing or direct access to our high quality A/D converter. Separate gain controls
on analog and digital outputs allow you to optimize the unit for simultaneous
applications.
Digital outputs include S/PDIF, TOSLINK or ADAT (front panel selectable). The A/D is
front panel adjustable from 44.1KHz-96KHz or syncs to ADAT or external word clock
(32KHz-100KHz). You can patch into any ADAT stream and select which pair (or ALL)
of channels the DPS II transmits.
The DI/O Preamp System II also features ART Analog to Digital conversion system
and ART Tube Technology similar to that of the ART D/IO. This ensures that when you
are going from the analog preamplification to digital, your signal will be as warm and
musical as you decide it to be.
DPS II FEATURES:
• Dual Analog VU metering
• Dual LED input metering
• V3 (Variable Valve Voicing) with OPL (switch selectable)
• Over 75 dB of gain
• Adjustable input impedance
• Hand selected 12AX7A dual triode tube
• Balanced XLR inputs and outputs
• 1/4” High impedance Instrument input and _” line level output
• Automatic instrument input switching
• +48V Phantom Power (switch selectable)
• Phase Reverse Switch
• Gain (+20dB) Switch
• Input Gain Control
• Output Level Control
• ART A/D Conversion
• Lower Noise At Low Gains
• ADAT, S/PDIF, TOSLINK Digital Interfaces
• 24-bit/96 KHz Operation
• Fully shielded all-steel chassis
• Designed and developed in the USA
INSTALLATION
The DPS II may be used in a wide variety of applications and environments. In a
rack-mountable, all-steel enclosure, the unit is designed for continuous professional
use. Mounting location is not critical. However, for greater reliability we recommend
that you not place the units 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 DPS II has an internal 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.
Analog Audio Connections
Audio connections to and from the DPS II are balanced XLR (Pin 2 = Hot (+), Pin 3 =
Cold (-), Pin 1 = Ground) and unbalanced _” (Tip = Hot (+), Sleeve = Ground). We
recommend that you switch off the +48V Phantom Power whenever changing
connections to the XLR input. The front mounted jacks can act as both a balanced XLR
connection, and an unbalanced _” connection.
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 userserviceable parts inside. When applicable, only use the power adapter that came with
this unit or one obtained from the ART Customer Service Department.
CONTROLS & INDICATORS
Input Control
The Input Control sets the amount of input gain of the DPS II. Turn the control
clockwise to increase gain and counterclockwise to decrease gain. You may
control two ranges of gain with this control, +20 to +68dB and +0 to +48dB.
Selection of the gain range is made with the +20dB gain switch.
NOTE: This control, along with the +20 dB Switch, is responsible for any
saturation of the tube. To change the tube character, utilize these 2 controls.
+20db Gain Switch
Use the +20dB Gain Switch to set the gain range of the input control. When the
switch is out, the unit operates in Normal mode. Depressing the switch adds
20dB of gain. For microphone applications, where more gain is needed, push the
switch in. For hot line level inputs, set the switch in the out position.
This switch also affects the tube circuit. When selecting +20dB of gain, the tube
is driven harder and becomes the dominant source of gain and overload
character.
Input Impedance Control
The same microphone can sound different on various pre-amps. One reason is
that every pre-amp presents a different load to on its’ input, some even change
as gain is changed! Our third generation discrete front end was designed to be
absolutely transparent. Every nuance of the microphone is maintained providing
detail masked by inferior pre-amps. The Input Impedance control is one key
element in providing new versatility in voicing microphones.
NOTE: the Input impedance control only affects the cannon connector inputs.
The 1/4” instrument input on the front panel is NOT affected by this control in any
way. The instrument input impedance is ALWAYS >1M Ohm.
Dynamic microphones are affected as much as phantom powered units.
DPS II™ Front Panel Features – pictured above
Phantom Power +48v Switch
The DPS II 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 DPS II circuitry slowly applies and removes the +48volts, to
prevent damage to microphones.
Be sure to turn down or mute the output of the DPS II 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 1/4” 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.
V3 – Variable Valve Voicing Control
The DPS II features ART’s proprietary V3 technology. V3 (which stands for
Variable Valve Voicing), provides optimized reference points to begin the
recording process for guitars, bass guitars, synths, acoustic instruments,
percussion and more.
ART engineers ran our preamplification circuit through a battery of tests and real
life studio conditions. Our goal was to create a processor that would allow a user
to have presets that were optimized for specific recording applications. We set
out to create a preamp that would be nimble enough to handle both violins and
kick drums, and everything in between.
We wanted to take the guessing out of the equation – and that is how we
developed V3™. It’s simple, easy and it works really well.
For example, if you are recording an acoustic guitar, V3™ has a preset that has
been optimized for that instrument. Once the preset is chosen, the user can even
fine tune the signal – which shows the true power of V3™ technology…it’s
tweakable. V3™ even features a multi setting, which is useful for a wide variety
of applications – like overhead micing, broadcast and field recording.
This means that it is now quicker and easier than ever to make great recordings!
Musicians want to play, not waste time adjusting knobs. No other microphone
preamp is as user-friendly as the DPS II.
LED Input Meter
The Input Meter displays the output level of the discrete mic pre-amp, before the
tube gain circuit. This peak-weighted meter allows you to get the best noise
performance out of the unit and prevent input clipping.
The signal level should average –6 to 0 dB on the meter, occasionally hitting the
clip light on the highest peaks. When the meter is in this range, you are getting
the lowest noise and distortion out of the pre-amp stage.
Adjust the Input control to keep the meter in this range. The +20dB switch does
not affect the meter, as it is part of the tube gain stage.
VU Meter
The VU Meter gives an analog representation of the DPS II tube signal level.
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 DPS II. 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 preamp. The marking on the output control determines the meter
calibration to output level. If the Output control is set to –10, then the output of
the unit is –10dBu when the meter reads 0 VU. For +4 (pro) systems, set the
Output control to +4 and the meter will be calibrated to your system levels.
DIGITAL CONTROLS
Digital Level Knobs
The digital level knobs control the input gain to the digital converters of the DPS
II™. The purpose of the digital level control is to get the loudest possible signal
into the converters before clipping starts to occur. The front mounted clip lights
easily notify the user before digital clipping occurs. For the optimal input signal,
raise the gain until the digital clip lights just start to flicker, then back off on the
digital level by a hair until the clip lights go out. One should most likely test this
using the hottest signal they will be using (or use the OPL™ feature on the V3™
setting to get your levels just right.)
There are several paths in which audio can reach the digital signal converters.
One is the using the analog inputs of the DPS II™. When used in said manner,
the analog signals of both channels in the DPS II™ automatically go into the
digital converters.
On the back of the DPS II™ there is a side chain. One can either send out the
signals to an effects processor, such as an ART Dual Levelar for additional
compression, and return it to the DPS II™ using the rear TRS jacks on the back.
One could also patch directly into the returns off the side chain, and patch
something directly to the A/D converters.
Sample Rate Control
This button controls the current sampling rate the DPS II™ is working at. By
cycling through the various settings, displayed by the upper LED row, one can
use a variety of sampling rates. When the ADAT setting is used, the DPS II™
syncs to incoming ADAT clock on the ADAT input. If the ADAT LED is blinking,
the DPS™ has failed to find a valid ADAT clock. When the LED is solidly lit, it
has found an acceptable ADAT clock signal. When EXT is selected, the DPS II™
looks to the Word Clock input and synchronizes itself to that. If no word clock
signal is present, the LED will blink informing you of that no valid word clock
signal is present.
Typically, the higher the sample rate, the more accurate the digital conversion is but frequently, one is limited by the digital recording system being used. Make
sure that, when selecting your sampling rate, the digital recording system you are
working with is operating at the same rate.
ADAT Channel Control
This button controls the current ADAT channel the DPS II™ is transmitting over.
The DPS™ only transmits over ADAT when the sample rate is set to 44.1KHz,
48KHz (ADAT master clock mode), ADAT (ADAT Slave Clock mode), or EXT
(Word Clock Sync mode). By toggling through, one can select to transmit over
channels 1-2, 3-4, 5-6, 7-8, or all 8 of them at once. When no lights are on, this
means all incoming ADAT channels are bypassed. This is frequently used when
the DPS II™ is in an ADAT chain, but not currently being used.
CONNECTIONS
It is easy to interface the unit with a wide variety of equipment. The
front panel houses 2 dual-purpose 1/4” / XLR input jacks, and the rear
houses balanced XLR ins and outs as well as unbalanced 1/4” outs.
Standard 1/4” and XLR inputs and outputs make patching simple.
ANALOG CONNECTIONS:
Dual Purpose Input Jacks (Front)
The front mounted, dual-purpose jacks act as both balanced XLR jacks, and
unbalanced 1/4” jacks.
The XLR Input jacks are primarily intended for microphone input, and as such,
can furnish Phantom Power when needed. They can handle up to +19 dBu
signals, which is the hottest signal you would get out of any microphone. For
even hotter input signals, you should use the 1/4” input jack. The XLR Input jack’s
variable input impedance is extremely flat over a wide frequency range, which
allows it to be voiced to virtually any microphone (one of the lesser known
secrets – it’s why the unit will always sound good!).
The 1/4” Input jacks are for instrument and line level inputs. They have high input
impedance to minimize any loading effects on instrument pickups. They can also
handle up to +22 dBu signals for line level signals.
When a device is plugged into the 1/4” input jack, the mic pre-amp is bypassed.
This allows you to keep the rear cannon input connected and override the mic
input when you plug into the front panel instrument input. The Instrument input is
NOT affected by the input Impedance control, it is always a high-Z input.
Rear Input Jacks
The rear XLR and 1/4” input jacks are directly wired together. The 1/4” jack being
wired TRS balanced (Tip = HOT, Ring = COLD, Sleeve = GROUND). The rear
panel 1/4” jack is intended for low level line inputs. The input impedance of these
jacks varies with the Input Impedance control from 150 to 3000 Ohms.
Use the front panel 1/4” input for instruments and unbalanced line level signals.
If the front 1/4” input is in use, the DPS II will use the instrument input and ignore
the rear panel inputs.
XLR Output Jacks (Rear)
The XLR Output jacks of the DPS II are active balanced. You may use them in
an unbalanced configuration without harm to the output circuitry. The XLR
outputs 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 the
DPS II™ 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.
1/4” Output Jacks (Rear)
The 1/4” Output jacks are 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 DPS II as a direct box for instruments
or line level signals. Make sure that both pieces of equipment connected to the
preamp’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 preamp’s output. This interrupts the ground path, and
therefore breaks the loop.
DIGITAL CONNECTIONS
S/PDIF COAX Out (Rear)
The digital coax output jack on the DPS II™ is an RCA type that outputs S/PDIF
stereo signals over a coaxial shielded cable. The data format is S/PDIF stereo 24
bit data at up to 100KHz sampling rate.
Due to the wide bandwidth, A R T recommends the use of high quality, low loss,
fully shielded cabling for the S/PDIF Coax connection. Note that the S/PDIF out
must act as a master. On the digital system you are connecting the S/PDIF cable
to make sure the device is set to sync to the incoming S/PDIF signal to ensure a
high quality transmission.
OPTICAL ADAT Input (Rear)
The optical input of the DPS II™ allows the user to use the DPS II™ within an
ADAT chain. The DPS II™, when set to ADAT mode, synchronizes its sample
rate with that of incoming ADAT clock signals. When in ADAT mode or EXT
mode, the DPS II™ can transmit on channels 1-2, 3-4, 5-6, 7-8, all channels, or
merely act as an ADAT through. When the DPS II™ is acting on 44.1 or 48 KHz
sampling rate, it acts as an ADAT master, and it can only pass through ADAT
channels if the source ADAT is in sync with the DPS II™.
OPTICAL ADAT Output/TOSLINK (Rear)
The optical inputs are used for both TOSLINK and ADAT transmission. To
transmit ADAT digital audio, the unit must be in 44.1KHz, 48 KHz, ADAT, or EXT
mode. When in 44.1 or 48 KHz mode, the DPS™ acts as an ADAT master clock,
when in ADAT mode the DPS™ syncs to incoming ADAT clock, and when in
EXT, the DPS™ syncs to incoming Word Clock. In all 3 of these modes, one may
set the ADAT transmission channels. When the output is set to S/PDIF, the
DPS™ uses TOSLINK instead of ADAT transmission over the optical connection.
WORD CLOCK Input (Rear)
The BNC connection on the back of the DPS II™ is used to synchronize the unit
with an incoming Word Clock signal. To allow the DPS™ to sync up with the
Word Clock input, set the Sample Rate to EXT. If no valid Word Clock signal is
present, the EXT light will blink, notifying the user that it was unable to
synchronize.
1/4” Inserts (Rear)
The DPS II™ has 2 channel inserts that are routed just before the digital
converters. The 2 female TRS jacks can be used to send the DPS II analog
signal to an external processing device, and then return the effected signal to the
digital converters. The RING of the TRS is used to send the signal out, and the
TIP is routed to the digital converters. One could also simply plug the output of a
device directly into the insert jacks to directly go into the converters.
DPS II™ SIGNAL FLOW DIAGRAM
The above diagram outlines the signal flow of the DPS II™. It provides for a handy
optical reference for what is occurring to the signal, and the various features of the
DPS II™, and their location and interaction with the signal.
OPERATION
The DPS II is one of the most versatile preamplification systems available.
Through use of the V3 technology, the DPS II™ can process numerous
instruments. Simply mic the instrument (if acoustic), amp, speaker, or plug the
instrument directly in to take full advantage of V3™ technology.
V3
Settings and their applications when processing:
When observing the V3 dial from a clockwise perspective, the following
settings are:
Neutral Settings:
These are useful for uncolored, natural reproduction of sound.
6:00 - Neutral Flat
6:45 – Neutral Vocal (Microphone)
7:30 – Neutral Guitar Amplifier
8:15 – Neutral Bass Guitar
Warm Settings:
These are useful when warming a signal is desired.
9:00 – Warm Electronic Keyboard
9:45 – Warm Electric Guitar
10:30 – Warm Vocal Microphone
11:15 – Warm Valve
Warm Settings with OPL:
These are useful with high sound pressure levels, close proximity micing, and
spiky transients, as well as warming the signal.
12:00 – Warm OPL Multiple Applications
12:45 – Warm OPL Vocal
1:30 – Warm OPL Acoustic Guitar
2:15 – Warm OPL Piano
Neutral Settings with OPL:
These are useful with high spl’s, close micing and spiky transients, as well as
maintaining clarity.
3:00 – Neutral OPL Bass Guitar
3:45 – Neutral OPL Acoustic Guitar
4:30 – Neutral OPL Percussion
5:15 – Neutral OPL Limit
Using V3
The V3 presets have been voiced with the intent of being a starting point for the
recording process.
The key to good recordings is to consider all the variables you will encounter during the
process.
For example…which microphone are you using? Are you recording a particularly bright
guitar into a very trebly guitar amplifier? Are the strings on your acoustic made of metal
or nylon? Is the room live or flat?
We mention this because V3 is intended as a reference, not a hard-and-fast
absolute. For your particular applications, your bass guitar may sound better through a
non-bass preset.
If you need to, give it a twist…you’ll find the setting for the tone you are searching for!
The DPS is ideal for use as a DI box. Plug the instrument into either input and use
the XLR or 1/4” (or both) outputs to connect to your recorder, board or PA system.
Because of its low noise, excellent tonal qualities, and high quality digital converters,
the DPS is ideal for running mixes through before recording to DAT, ADAT, DAW, or
even into your computer. Used as a mastering device, the preamps are capable of
adding warmth and gentle tube compression to the signal. Variable Input and Output
level controls make the preamps in the DPS ideal for level matching material in post
production situations…an extremely valuable use!
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.
2) If you find the unit to be at fault, write down a complete description of the problem,
including how and when the problem occurs. Please write down a description of your
complete setup before calling Customer Service.
3) Contact our Customer Service Department at (585) 436-2720 for your Return
Authorization number or questions regarding technical assistance or repairs. Customer
Service hours are 9:00 AM to 5:00 PM Eastern Time, Monday through Friday.
4) Pack the unit in its original carton or a reasonable substitute. The packing box is not
recommended as a shipping carton. Put the packaged unit in another box for shipping.
Print the RA number clearly on the outside of the shipping box. Print your return
shipping address on the outside of the box.
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 a description of the
problem.
6) Ship your unit (keep your manual!) to:
APPLIED RESEARCH AND TECHNOLOGY
215 TREMONT STREET
ROCHESTER, NEW YORK 14608
RA# ____________________
Fill in the following information for your reference:
Date of purchase ___________________
Purchased from ___________________
Serial number___________________
DPS II SPECIFICATIONS
Dimensions1.75”H x 19”W x 6.5”D
Weight5.5 lbs.
Analog Input ConnectionsFront: XLR (balanced)
Analog Output Connections XLR (balanced), 1/4” TS,
Digital Input ConnectionsADAT Optical, Word Clock BNC
Digital Output ConnectionsADAT Optical/TOSLINK, S/PDIF RCA
Analog Input Impedance XLR, 1/4” 150-3K Ohms, 1M ohm
Analog Output Impedance XLR, 1/4” 300 ohms,150ohms
Word Clock SpecificationsBNC jack, 5V max.,
Digital Level -∞ to +10dB
Digital Output SpecificationsS/PDIF RCA 75 ohms, 0.5 Volt
Maximum Input Level +19dBu
Maximum Output Level, XLR+28dBu
Maximum Output Level, 1/4” +22dBu
CMRR>75dB (typical @ 1KHz)
Frequency Response5Hz to 50KHz, +/-.1dB
Dynamic Range>100dB
Total Harmonic Distortion<0.01% (clean), <0.1%(warm)
Maximum Gain
XLR to XLR80dB
Inst. to 1/4” 68dB
XLR to 1/4" 74dB
Inst. to XLR74dB
Equivalent Input Noise (EIN)
XLR to XLR-129dBu (A weighted)
Inst. to 1/4” -105dBu (A weighted)
Tube Type12AX7A, Dual Triode, Hand Selected
Power RequirementsUSA – 110-125V AC / 50-60hz/ 16W export
Rear: Switchable XLR (bal.)/ 1/4” TS,
Ext. sync mode source
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.