Theta Digital Dreadnaught User manual

THETA DIGITAL
Dreadnaught D
Owner’s Manual

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PREFACE CONGRATULATIONS
The Dreadnaught D modular amplifier is among the most advanced available. By combining high-power
linear power supplies and the Class D, N-Core NC-1200 amplifier modules, Theta Digital’s has delivered an
amplifier that closely approaches the theoretical ideal: a straight wire with gain.
IMPORTANT
Save all packaging in a dry place away from fire hazards. Your Dreadnaught D is a precision electronic
instrument and should be properly packaged any time shipment is made. In the unlikely event that you
have to return your Dreadnaught D to the factory for service, or if you send it to us for updating, the
original packaging will best protect the unit from shipping damage.
In order to achieve the fullest flexibility and enjoyment from your Dreadnaught D, we at Theta recommend
that you read this manual in full before connecting the unit to your audio/video system.
Note: It is imperative that the Dreadnaught D be operated in a well-ventilated environment and the
immediate external temperature be maintained as specified. External cooling fans may be required in some
cases. Do not stack any equipment directly above or below the Dreadnaught D to protect it from
overheating, as well as the continued functionality of any equipment near and around it.
©2002-2015 Theta Digital. All rights reserved.
This manual is also available for download as a PDF file at Theta Digital’s website.
http://www.thetadigital.com
No part of this publication may be reproduced or transmitted in any form or by any means, electronic or
mechanical, for any purpose, without the express written permission of Theta Digital.

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The lightning flash with arrowhead symbol, within an equilateral
triangle, is intended to alert the user to the presence of uninsulated
“dangerous voltage” within the product’s enclosure that may be of
significant magnitude to constitute a risk of electric shock to
persons.
The exclamation point within an equilateral triangle is intended to
alert the user to the presence of important operating and
maintenance (servicing) instructions in the literature accompanying
the product.
WARNING TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS PRODUCT TO RAIN OR MOISTURE
CAUTION: TO PREVENT ELECTRIC SHOCK, DO NOT USE THE AC (POLARIZED) PLUG WITH AN EXTENSION
CORD, RECEPTACLE OR OTHER OUTLET UNLESS THE BLADES CAN BE FULLY INSERTED TO PREVENT BLADE
EXPOSURE.
Extension cords are not recommended for use with this product.

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Dreadnaught D Identification Record
This information is for your records and for future identification of the Dreadnaught D. Please take a
moment to fill out all pertinent data now, and as upgrades and/or options are installed. Whenever
upgrades, inquiries and/or changes are requested, the serial number will be required.
SERIALNUMBER
DATEPURCHASED
DEALER’SNAME
DEALER’SADDRESS/PHONE
INSTALLEDCARDS/OPTIONS
(Dateofinstallation)
(Dateofinstallation)
(Dateofinstallation)
(Dateofinstallation)
(Dateofinstallation)
(Dateofinstallation)
(Dateofinstallation)

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SAFETY PRECAUTIONS
Please carefully read each item of the operating instructions and safety precautions before installing and
using this product. Use extra care to follow the warnings written on the product itself and/or in the
operating instructions. Keep the operating instructions and safety precautions for future reference.
CAUTION: TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE ANY OF THE COVER PANELS.
NO USER-SERVICEABLE PARTS INSIDE. REFER ALL SERVICING TO QUALIFIED SERVICE PERSONNEL ONLY.
TO PREVENT FIRE OR SHOCK HAZARD, DO NOT ALLOW LIQUIDS TO SPILL OR OBJECTS TO FALL INTO
ANY OPENINGS OF THE PRODUCT.
THIS UNIT IS SUPPLIED WITH A TWO 3 PIN GROUNDED AC PLUGS. ALWAYS INSERT THE AC PLUG INTO A
GROUNDED OUTLET. DO NOT REMOVE THE GROUND PIN OR DISABLE THE GROUND FOR ANY PURPOSE.
BEFORE MAKING ANY CONNECTIONS TO THE DREADNAUGHT D, FIRST TURN OFF THE POWER AND THEN
DISCONNECT THE AC POWER CORD.
WHEN INSTALLING THE DREADNAUGHT D IN YOUR SYSTEM, MAKE CERTAIN TO ALLOW A MINIMUM OF ½
INCH OF VENTILATION ON EACH SIDE OF THE UNIT. ALSO ALLOW AT LEAST 3 INCHES OF VENTILATION
SPACE ABOVE THE UNIT. IMPROPER VENTILATION OF THE UNIT MAY CAUSE OVERHEATING, WHICH MAY
DAMAGE THE UNIT AND CAUSE A FIRE. PLACE THE UNIT ON A SOLID SURFACE ONLY. I.E. NOT ON
CARPET, ETC.
DO NOT PLACE THE DREADNAUGHT D NEAR HEAT SOURCES SUCH AS DIRECT SUNLIGHT, STOVES, HEAT
REGISTERS, RADIATORS OR OTHER HEAT PRODUCING EQUIPMENT.
TO PREVENT DAMAGE TO THE ANALOG OUTPUT CIRCUITRY, BE CERTAIN NOT TO SHORT THE OUTPUT
SIGNAL TO GROUND. ENSURE THAT YOUR AUDIO OUTPUT CABLES DO NOT HAVE ANY INTERNAL
SHORTS BEFORE CONNECTING THEM TO THE DREADNAUGHT D.
IF REPLACEMENT OF THE AC LINE FUSE AND/OR ANY INTERNAL FUSE BECOMES NECESSARY, REPLACE
ONLY WITH SAME VALUE AND TYPE OF FUSE. NEVER BYPASS THE FUSE.
IF THE AC CORD BECOMES DAMAGED, DO NOT USE IT. IMMEDIATELY REPLACE IT WITH A NEW ONE OF
THE SAME OR BETTER RATING.
IT IS IMPERATIVE THAT THE DREADNAUGHT D BE OPERATED IN A WELL VENTILATED ENVIRONMENT AND
THE IMMEDIATE EXTERNAL TEMPERATURE BE MAINTAINED AS SPECIFIED. EXTERNAL COOLING FANS
MAY BE REQUIRED IN SOME CASES. DO NOT STACK ANY EQUIPMENT DIRECTLY ABOVE OR BELOW THE
DREADNAUGHT D AS TO PROTECT IT FROM OVERHEATING, AS WELL AS THE CONTINUED
FUNCTIONALITY OF ANY EQUIPMENT NEAR AND AROUND IT.
AFTERMARKET and THIRD PARTY MODIFICATIONS
Please note that any aftermarket and/or third party modifications will void the warranty. In the case of
changing the feet on a unit, in order to prevent any damage (which will also not be covered under
warranty), please verify that the screws being used to secure non-Theta feet do not screw any deeper into
the chassis than the original ones. The original screw is 1/4-20 by 1/2 and goes into the chassis 1/4 inch.

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Table of Contents
PREFACE...................................................................................................................... ii
WARNING................................................................................................................. iii
Dreadnaught D Identification Record .................................................................................iv
SAFETY PRECAUTIONS ....................................................................................................v
INTRODUCTION .............................................................................................................. 1
Getting to know your Dreadnaught D ................................................................................. 1
Burn-In Time .............................................................................................................. 1
Reference Manual Conventions......................................................................................... 1
IMPORTANT NOTICE..................................................................................................... 2
Front Panel Layout....................................................................................................... 3
Front Panel Layout – Rackmount Option.............................................................................. 4
Rear Panel Layout........................................................................................................ 5
OPERATION................................................................................................................... 7
Single and Two channel Modules....................................................................................... 7
Remote Triggers.......................................................................................................... 7
Appendix A Troubleshooting Guide ............................................................................... 8
Appendix B Specifications.......................................................................................... 9

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INTRODUCTION
Getting to know your Dreadnaught D
This Dreadnaught D has been put through a rigorous and unique testing procedure that ensures that it will
last for many years with minimal service requirements. This procedure includes the following:
• All assembled circuit boards are given a thorough visual inspection and are then tested in a bench-
reference Dreadnaught D.
• The tested, assembled circuit boards are then installed in a new Dreadnaught D and the whole unit
is tested for every function and parameter.
• The unit is put on a burn-in torture rack to test for any possible component failures.
• It is then tested on an audio analyzer for all pertinent parameters.
• The unit has all remaining chassis components installed and then undergoes a complete visual
inspection, which assures that all Dreadnaught D’s meet visual specifications.
• The Dreadnaught D then undergoes a critical listening and functional test.
Burn-In Time
While the Dreadnaught D amplifier will sound wonderful without any burn-in time, users may experience
small sonic improvements during the first week or so of operation.
Reference Manual Conventions
For clarity purposes, references to buttons and LED’s will be shown in bold capital letters.

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IMPORTANT NOTICE
I. It is imperative that the Dreadnaught D be connected to a ground via its three wire AC power
cord. It is important that the AC power outlet, which the Dreadnaught D is plugged into, is
actually grounded. Failure to do so will severely compromise the performance, reliability and
safety of use of the Dreadnaught D.
III. Ventilation is an important issue when placing the Dreadnaught D in a system. Make certain that
the Dreadnaught D is placed in a well-ventilated area or rack unit.
IIII. Please take note that some powerline conditioners defeat the AC power ground on their outlets.
If the intention is to plug the Dreadnaught D into a line conditioner, check with your dealer to
make certain that the particular conditioner that is intended for use DOES NOT DEFEAT THE AC
GROUND on its AC outlets. Only the highest powered line conditioners should be considered for
use with the Dreadnaught D. Otherwise, the amplifier’s power output may be compromised.
IV. DO NOT remove any cover panels from the Dreadnaught D, as there are no user serviceable
components inside. Refer servicing and updating to qualified service personnel only.
V. Endcaps on all unused RCA inputs will improve the sound quality and may reduce the susceptibility
to RF induced anomalies.
VI. It is imperative that the Dreadnaught D be operated in a well ventilated environment and the
immediate external temperature be maintained as specified in Appendix B of this manual.
External cooling fans may be required in some cases. Do not stack any equipment directly above
or below the Dreadnaught D, to protect it from overheating, as well as the continued functionality
of any equipment near and around it.

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Front Panel Layout
Figure 1a - Front Panel Layout
1. STANDBY button. After the left-hand (when viewed from the front of the amplifier) rear-panel POWER
switch is turned on, press the front panel STANDBY button to exit the standby mode. The channels in the
two left most slots (when viewed from the front of the amplifier) will come out of standby. The channels in
the two right-hand slots (when viewed from the front of the amplifier) are controlled by the right-hand
rear-panel POWER switch. If both rear-panel POWER switches are turned on, the STANDBY button will
control all 4 rear-panel amplifier slots.
2. STANDBY LED. Illuminates RED when the amplifier enters the Standby mode. Illuminates GREEN when the
amplifier is in the turn-on sequence. Illuminates BLUE when the amplifier is ready for normal operation.
3. PROTECT LED. Illuminates if the unit enters the protection mode. This can be caused by a short circuit in
any of the channels or by an over-temperature operating condition.
1
3
2

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Front Panel Layout – Rackmount Option
Figure 1b – Rackmount Front Panel Layout
1. STANDBY button. After the left-hand (when viewed from the front of the amplifier) rear-panel POWER
switch is turned on, press the front panel STANDBY button to exit the standby mode. The channels in the
two left most slots (when viewed from the front of the amplifier) will come out of standby. The channels in
the two right-hand slots (when viewed from the front of the amplifier) are controlled by the right-hand
rear-panel POWER switch. If both rear-panel POWER switches are turned on, the STANDBY button will
control all 4 rear-panel amplifier slots.
2. STANDBY LED. Illuminates RED when the amplifier enters the Standby mode. Illuminates GREEN when the
amplifier is in the turn-on sequence. Illuminates BLUE when the amplifier is ready for normal operation.
3. PROTECT LED. Illuminates if the unit enters the protection mode. This can be caused by a short circuit in
any of the channels or by an over-temperature operating condition.

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Rear Panel Layout
2 – Rear Panel Layout showing both single and two channel modules installed
1 & 17. MAIN POWER Switches. (#17 is the Master Power Switch. Neither side of the amplifier will operate if
this switch is set to off.) #1 controls the left-hand amplifier slots and disconnects AC to all circuits. It is
recommended that this be left ON at all times during regular use with the exception of whenever cables are
connected/disconnected or when the unit will to be used for an extended period of time.
2 & 18. Rear panel FUSE. If necessary to replace, use same type and rating only.
3 & 19 IEC POWER INLETS. Attach supplied line cord to these receptacles.
4. SINGLE ENDED (RCA) INPUT JACK
5. INPUT SELECTOR SWITCH. Selects the single ended (RCA) or the balanced (XLR input).
6. BALANCED (XLR) INPUT JACK.
7. POSITIVE BINDING POST. Connects to the + (plus) speaker connector. The binding posts can accept spade
lugs, banana plugs or bare wire.
8. NEGATIVE BINDING POST. Connects to the – (minus) speaker connector
9. MONO AMPLIFIER MODULE. There are two single channel amplifier modules available for the Dreadnaught
D. One has a single NC-1200 N-Core amplifier card installed. The other offers bridged mono performance
using two NC-1200 N-Core cards. Please see items 10 and 11 for markings as to which is installed in your
Dreadnaught D.
10. BRIDGED MONO AMPLIFIER INDICATOR. A green mark here indicates the use of a bridged mono amplifier
module.
11. SINGLE MONO AMPLIFIER INDICATOR. A green mark here indicates the use of a mono amplifier module.
12. BLANK COVER PLATE. Used when no amplifier module is installed in the amplifier slot.
13. 120V INDICATOR. A green mark here denotes the amplifier is ready for 120 V operation.

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14. 220 – 240V INDICATOR. A green mark here denotes the amplifier is ready for 220 to 240 V operation.
15. GROUNDING LUG. Used to interconnect chassis of associated components if necessary.
16. REMOTE TRIGGER.
17. MASTER POWER SWITCH. Disconnects AC to all circuits. If power switch 1 is set to OFF, controls the right
hand amplifier slots only. It is recommended that this be left ON at all times during regular use with the
exception of whenever cables are connected/disconnected or when the unit will not be used for an
extended period of time.
18. Rear panel FUSE. If necessary to replace, use same type and rating only.
19. IEC POWER INLET. For the right-hand power supply. Attach supplied line cord to this receptacle.
.

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OPERATION
Before turning on the Dreadnaught D, ensure that all precautions and warnings have been carefully
reviewed and adhered to. Damage to the Dreadnaught D caused by improper operation, wiring and/or
ventilation will not be covered under warranty and Theta will not be liable for any consequential damage
or loss.
After the main rear power switches are turned on, the amp goes into Standby. The amplifier is completely
off, save for a very small (and low power) supply to power the soft start circuit. When the Standby button
is pressed, the soft start sequence begins and the LED turns green. Several relay clicks may be heard
while the amplifier readies itself for operation. When the turn-on sequence is complete the LED will
illuminate blue and the amp will be fully on. Pressing the Standby button again takes the amp directly into
the standby mode.
Single and Two channel Modules
The 4 slots of the Dreadnaught D can be loaded with any combination of 4 modules. Those available are
single (mono), two channel (stereo) and bridged (mono). Each module can be inserted into any of the four
rear-panel slots.
Note: The speaker output polarity on the single channel modules is identical to the polarity of the stereo
module. The maximum spade lug thickness for any module is 1/16”
Remote Triggers
Use the remote trigger to connect to a compatible preamplifier, source device or other product with 5 to
12 VDC output. When so interconnected, the Dreadnaught D will turn on and off in response to the signals
received from the source device. The trigger circuit requires a steady-state signal. Units that send a pulse
signal for turn-on and turn-off will not work with the Dreadnaught D.

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Appendix A Troubleshooting Guide
If the Dreadnaught D should function abnormally during operation, please review the items in the
following checklist. Please be sure to thoroughly check all other connected components such as speakers,
preamplifiers, as well as cables.
Symptom Possible Cause(s)
Remedy
No power or front panel
lights and no sound. Power cable is not inserted 100% into AC input connector. Ensure that the AC cord is inserted all the way into the Dreadnaught D and that the
wall outlet is active.
Rear panel fuse is open. Replace with same type and rating ONLY.
Circuit breaker is open (AC outlet). Check the AC outlet circuit breaker and
reset, if necessary, or contact your dealer.
No audio output. Overheating If the front panel PROTECT LED illuminates,
this could indicate overheating. Shut down
the Dreadnaught D until in cools. This should
be a very rare occurrence. If it does happen,
an external fan may be required

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Appendix B Specifications
Analog Audio Inputs 1 Single-ended RCA jack per channel.
1 Balanced (XLR) jack per channel
Input Impedance 47 kOhms. Single-ended or Balanced for each phase
Input Sensitivity (Single-Ended) 1.825 V RMS input for 225W into 8 ohms
(Balanced) 1.825V RMS input for 225W into 8 ohms
Gain (Single-Ended or Balanced) 27.8 dB
Polarity (Single-Ended) Non-Inverting
(Balanced) Pin-2 = Positive, Pin-3 = Negative for Non-Inverting Output
Analog Audio Outputs One balanced output with 5-way binding posts per channel
Modes /Process Standby: Amplifier is ready to be turned on via front panel switch or remote
trigger.
Overcurrent, D.C., and/or thermal protection: Amplifier will cycle.
Catastrophic D.C. or output stage failure: Amplifier will shut down.
Power Output
Mono or Stereo Module 8 ohms: 225W RMS per channel with less than 0.05% THD from 20 Hz to 20 kHz
4 ohms: 375W RMS per channel with less than 0.05% THD from 20 Hz to 20 kHZ
2 ohms: 500W RMS per channel with less than 0.05% THD from 20 Hz to 20 kHz
Mono Bridged Module 8 ohms: 500W RMS per channel with less than 0.05% THD from 20 Hz to 20 kHz
4 ohms: 800W RMS per channel with less than 0.05% THD from 20 Hz to 20 kHz
Not recommended for operation below 3 ohms.
Frequency Response +0, -.5 dB 0 Hz to 20 kHz, load independent
Damping factor >6000 at 100 Hz; >2000 at any frequency up to and including 20 kHz
Signal to noise ratio 120 dB referenced to rated output (A-Weighted)
Crosstalk > 85 dB
Power Requirements 117V AC, 15A Slo Blo main fuse; 230V AC 8A Slo Blo main fuse; 50/60 Hz
Power Consumption Less than 1W at Standby; <80W at idle; 1500W maximum x 2 when fully loaded
Trigger Input 5-12 VDC; Steady State
Dimensions (W x H x D) 17 5/8” x 7 15/16” x 19 ¾”; 448 mm x 202mm x 502 mm
Weight (fully loaded) 98.5 lbs; 44.8 kG

90 DAY LIMITED WARRANTY TERMS AND CONDITIONS
(5 Year optional extended service contract)
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1. Theta Digital, henceforth referred to as Theta, warrants the product designated herein to be free of manufacturing
defects in material and workmanship, subject to the conditions set forth herein, for a period of 90 days from the
date of purchase by the original purchaser, henceforth referred to as purchaser. If the purchaser registers the unit
with Theta by mailing in the warranty card, together with a copy of the bill of sale, within 14 days of the date of
purchase, said purchaser will be registered for an extended service contract. Product registration may also be
completed by going to Theta Digital’s website at http://www.thetadigital.com/product_registration.asp The
extended service contract extends the 90 days to a period of 5 years from the date of purchase by the original
purchaser or no later than 7 years from the date of shipment to the authorized Theta dealer, whichever comes first.
2. CONDITIONS
This warranty is subject to the following conditions and limitations. The warranty is void and inapplicable if the
product has been used or handled other than in accordance with the instructions in the owner's manual, abused or
misused, damaged by accident or neglect or in being transported, or if the defect is due to the product being
repaired or tampered with or modified by anyone other than Theta or an authorized Theta repair center. In the
unlikely event that the unit requires service, contact Theta for an RA (Return Authorization) number. The product
must be packed and returned to Theta or an authorized Theta repair center by the customer at his or her sole
expense. Theta will pay return freight of its choice. A returned product must be accompanied by a written
description of the defect, a photocopy of the original purchase receipt, and a daytime phone number where the
owner can be reached. The unaltered receipt must clearly list model and serial number, the date of purchase, the
name and address of the purchaser and authorized dealer and the purchase price. Theta reserves the right to
modify the design of any product without obligation to purchasers of previously manufactured products and to
change the prices or specifications of any product without notice or obligation to any person.
3. REMEDY
In the event the above product fails to meet the warranty, and the above conditions have been met, the purchaser's
sole remedy under the limited warranty shall be to obtain an RA number and return the product to Theta or an
authorized Theta repair center where the defect will be rectified without charge for parts or labor.
4. LIMITED TO ORIGINAL PURCHASER
This warranty is for the sole benefit of the original purchaser of the covered product and shall not be transferred to
a subsequent purchaser of the product.
5. DURATION OF WARRANTY
This warranty expires 90 days after the date of original purchase. If Theta receives the completed warranty
registration card within 14 days of original purchase, this period is extended to the fifth anniversary of the original
date of purchase or no later that the seventh anniversary of the shipment to the authorized Theta dealer, whichever
comes first.
6. MISCELLANEOUS
ANY IMPLIED WARRANTIES RELATING TO THE ABOVE PRODUCT SHALL BE LIMITED TO THE DURATION OF THIS
WARRANTY. THE WARRANTY DOES NOT EXTEND TO ANY INCIDENTAL OR CONSEQUENTIAL COSTS OR DAMAGES
TO THE PURCHASER. Some states do not allow limitations on how long an implied warranty lasts or an exclusion or
limitation of incidental or consequential damages, so the above limitations or exclusions may not apply to you. This
warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
7. WARRANTOR
Inquiries regarding the above limited warranty may be sent to the following address:
Theta Digital
1749 Chapin Road
Montebello CA 90640 USA
WARRANTY OUTSIDE THE USA and Canada
Theta has formal distribution in many of the countries of the free world, in each country the Theta Importer has
contractually accepted the responsibility for product warranty. Warranty service should normally be obtained from
the importing dealer or distributor from whom you obtained your product.
WARNINGS
1. To prevent fire or shock hazard, do not expose your Theta product to rain or moisture.
2. This unit contains voltages which can cause serious injury or death. Do not operate with covers removed. Refer all
servicing to your authorized Theta dealer.
3. For continued protection against fire hazard, replace fuses only with the same type and rating of fuses as specified.