Dan DAgoslino Relentless Preamplifier Preamp Owner’s Manual

: June 6, 2024
: Dan DAgoslino

Table of Contents

Dan DAgoslino Relentless Preamplifier Preamp
UNPACKING AND INSTALLATION
Installation requirements
OPERATION
DIGITAL STREAMING MODULE (DSM)
DIGITAL INPUT SELECTION FROM THE FRONT PANEL
MAINTENANCE
TROUBLESHOOTING
WARRANTY
SPECIFICATIONS
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Dan DAgoslino Relentless Preamplifier Preamp

A NOTE FROM DAN D’AGOSTINO
Founder and Chief Designer of Dan D’Agostino Master Audio Systems Sincere thanks for your purchase of the Relentless Preamplifier. We design and build Relentless level components for the truly discriminating listener. Incorporating the most sophisticated circuit topology and in a boldly elegant yet functional structure, the Relentless Preamplifier is an all-out assault on the preamplifier category.

The preamplifier plays a critical role in musical playback: the point in the reproduction stage when the music signal is particularly susceptible to compromise through noise and distortion. The use of three separate chassis in the design of the Relentless Preamplifier—a dedicated audio chassis for each channel separated by a power supply/control section—addresses these challenges and brings other benefits besides. This larger footprint provides the space required to fully exploit the FET-style front end pioneered in the Momentum HD Preamplifier. This new circuitry stage as executed in the Relentless Preamplifier reveals a level of detail and musicality not previously achieved.

Operationally, the Relentless Preamplifier is our first two-source/two-zone preamplifier, allowing two different sources to be played simultaneously in different parts of your home. The Relentless Preamplifier is also the first D’Agostino preamplifier to offer an optional Digital Streaming Module (DSM), housed in the power supply/control chassis and completely isolated from the analog circuitry.

As a part of the digital streaming capabilities, Tidal, Qobuz, and Spotify subscription services are available. With appropriately encoded music files, MQA decoding is standard. Customized apps for iOS devices provide easy control of music collections, streaming content, and unit control. Roon Music Management is also available as an alternative music management program.

Importantly, the Relentless Preamplifier builds on decades of experience designing and manufacturing the highest-performing audio products, combining the very finest and most advanced parts with the same labor-intensive, hand- crafted construction we have used since the company’s inception. Our staff of dedicated craftsmen and technicians work diligently to guarantee that every Relentless Preamplifier tests and meets the stringent specifications my engineering team have set for electrical, mechanical, and finish criteria.

I hope you find that your Relentless Preamplifier delivers the most spectacular sound quality you’ve ever experienced in your home. And I hope your eyes enjoy its singular, elegant design and impeccable craftsmanship as much as your ears enjoy hearing it.
Sincerely,

LEGAL NOTIFICATIONS
Dan D’Agostino Master Audio Systems is a registered trademark of Dan D’Agostino Master Audio Systems, LLC. The information in this owner’s manual is subject to change without notice. Current Version 1.0 of this manual was produced by the Dan D’Agostino Master Audio Systems, LLC engineering, sales, and marketing departments.

The information in this manual is the sole property of Dan D’Agostino Master Audio Systems, LLC. Any reproduction in whole or part without the expressed written permission of Dan D’Agostino Master Audio Systems, LLC is prohibited. No material herein may be transmitted in any way including either electronic or mechanical methods for any purpose without expressed written permission of Dan D’Agostino Master Audio Systems, LLC.

WARNING
Do not expose this amplifier to moisture or excessive humidity, and do not use it outdoors. Fire hazard may result.

The lightning flash with arrowhead, 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 sufficient magnitude to constitute a risk of electrical shock to persons.
The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating maintenance (servicing) instructions in the literature accompanying the appliance.

CAUTION
No user-serviceable parts inside. Do not open the amplifier’s chassis or remove any of its fasteners. Contact Dan D’Agostino Master Audio Systems, LLC or your dealer if you have service needs.

UNPACKING AND INSTALLATION

Package contents
If any of the following items are missing, please contact your dealer:

1 Relentless Preamplifier encased in protective static-cling vinyl
1 remote control
1 wireless remote control charging pad with USB cable
1 Bluetooth® antenna
1 Wi-Fi antenna if equipped with Digital Streaming Module
1 owner’s manual
1 pair of white lifting gloves
1 microfiber cleaning cloth
1 AC power cord

Unpacking the Relentless Preamplifier from its case
While the preamplifier is still in its crate, please move it to a location near the place where it will be installed. Remove all jewellery including watches, rings, and belts from your person to avoid damage to the exterior of the preamplifier during the removal and installation. We recommend that two people lift the Relentless Preamplifier.

The finish of the Relentless Preamplifier is durable, but it can be damaged if care is not taken. To maintain the preamplifier’s pristine surface, we strongly suggest wearing the supplied white lifting gloves when handling to avoid abrasion, fingerprints caused by oils from the skin, etc. See “Maintenance” for instructions on cleaning.

Installation requirements

The Relentless Preamplifier’s three metal chassis make it much heavier than the average preamplifier. Make sure the surface that will support the Relentless Preamplifier can safely hold its weight.
Adequate ventilation must be provided for the preamplifier. There should be two inches of clearance at the top, and the bottom vents must not be obstructed by thick carpet, dust, etc. We recommend that the preamplifier be installed in an open equipment rack to ensure proper ventilation. The preamplifier may be installed in a closed cabinet or an equipment closet, but the cabinet or closet must be designed with substantial ventilation at the top and bottom; active ventilation (i.e., powered fans) is preferred. Do not place the preamplifier directly on a carpeted surface.

If plugging the Relentless Preamplifier into a power strip or power conditioner, make sure it
is a high-quality unit that does not alter ground connections or insert current limiting elements in series with the AC mains signal.

The Relentless Preamplifier transmits power and control signals through specially made connectors mounted in the feet of each chassis. To assemble the preamplifier, place the audio chassis labelled Relentless Preamplifier Audio Chassis—Right Channel Bottom at the preamplifier’s final location. Place the chassis labelled Relentless Preamplifier Power Supply on top of the bottom audio chassis. Carefully ensure that the bottom plate connector makes solid contact with the audio chassis top plate connector. Place the remaining audio chassis labelled Relentless Preamplifier Audio Chassis—Left Channel Top on top of the power supply chassis. Carefully ensure that the bottom plate connector makes solid contact with the power supply chassis top plate connector.

Audio Chassis and Power Supply (front)

Standby/Power On button
Mute button
Polarity button
Zone 1 button
Zone 2 button
Volume control knob
Volume setting indicator
Source selector buttons

Audio Chassis and Power Supply (rear)

XLR input jacks
RS-232 control connector
Optional Digital Streaming Module
Access for preamplifier control programming
Access for DSM programming
12-volt trigger outputs
Zone 1 XLR output jacks
Zone 2 XLR output jack
Bluetooth® antenna
IEC power cord connector
Main power switch
Power supply DC output x 2 (for future products)

Remote Control

Wireless Charging Pad
Control touch panel
Standby button
Back button
Mute button
Selector arrows
Touch panel volume control
Display

MAKING CONNECTIONS TO THE RELENTLESS PREAMPLIFIER

Interconnect cables
We recommend the use of high-quality balanced XLR audio interconnect cables with the Relentless Preamplifier. If you have a source device that does not offer XLR connections, use high-quality XLR-to-RCA adapters.

First connect the source devices (phono preamplifier, CD player, etc.) to the appropriate inputs. Be sure to connect each XLR cable (or XLR-to-RCA adapter) to the appropriate XLR jack by pushing the plug into the jack. To release the plug, push on the small tab atop the jack and gently detach the plug. Never grasp interconnect cables by the cable itself—you could damage the cable. Use the top chassis for left channel connections and the bottom chassis for right channel connections.

Note: The Relentless Preamplifier does not incorporate a phono stage section; you must add an external phono stage to use the Relentless Preamplifier with a turntable. We recommend the Momentum Phonostage for use with the Relentless Preamplifier.

Connect the cables of the Relentless Preamplifier’s Zone 1 outputs to your amplifier(s). Use the top chassis for left channel outputs and the bottom chassis for right channel outputs.

Note : Each Relentless Preamplifier audio chassis includes two Zone 1 outputs. These are identical and can be used interchangeably. The most common use for the second set of Zone 1 outputs is for use with subwoofers.
Additionally, each Relentless Preamplifier audio chassis includes a Zone 2 output. Please see the Zone 2 operation section of this Owner’s Manual.

AC cord

The Relentless Preamplifier is supplied with a high-quality AC cord tipped with a 15-amp IEC connector at the preamplifier end and a three-conductor AC plug at the other end. You may use a different power cord with the Relentless Preamplifier if you wish, as long as it is tipped with a 15-amp IEC connector and a three-conductor AC plug.
After the speaker, interconnect cables, and power supply connector cable are connected, push the IEC connector on the power cord into the IEC jack on the Relentless Preamplifier.
If plugging the Relentless Preamplifier into a power strip or power conditioner, make sure it is a high-quality unit that does not alter ground connections or insert current limiting elements in series with the AC mains signal.

Remote Control operation
The Relentless Preamplifier remote control uses Bluetooth® 1.6 technology rather than typical IR operation. Bluetooth® 5.0 offers operational feedback and great improvement in usable range and does not require line of sight for proper operation. Please attach the included Bluetooth® antenna to the threaded antenna input on the rear panel.

12-volt trigger outputs
These 3.5mm jacks output a 12-volt DC control signal when the preamplifier is on. You can connect them to any device that accepts a 12-volt DC control input, such as an amplifier.

RS-232 input
This DB9-type input allows the Relentless Preamplifier to be controlled by home automation systems that use RS-232 protocol. Consult your D’Agostino Master Audio Systems dealer for more information.

OPERATION

Initial power-up of the preamplifier
To power up the Relentless Preamplifier, two switches are used. One is located on the back of the power supply; this switch turns the AC power on so the power supply will be active. The other is the Standby button located on the front of the preamplifier power supply chassis.

First, flip the switch on the back of the power supply to the On position. The Standby button
will illuminate. Press the Standby button on the front of the preamplifier. This will power up the preamplifier, turn off the Standby button LED, and illuminate the volume indicators.

After power is switched on, the Relentless Preamplifier requires approximately 30 minutes to reach optimal operating temperature. Although the preamplifier will sound excellent upon initial listening, the sound quality will improve as it warms up to operating temperature.

Basic operation—Zone 1 operation
The Relentless Preamplifier front panel offers basic functions: Standby, Mute, Polarity, Zone 1 and 2 selection, volume, and source selection. The remote control adds additional controls detailed in the
“Remote Control” section.

Front panel control

Standby: The Standby button is located on the front panel of the preamplifier. When the preamplifier is in standby (off) mode, the LED in the middle of the button will be lit. Push the button to turn the unit on. When power is on, the LED in the middle of the button will go off and the volume indicator will illuminate. Push the button once more to turn the unit off. The light for the volume indicator will go out and the LED in the middle of the Standby button will light up. The Relentless Preamplifier defaults to Zone 1 and the Zone 1 LED will also illuminate upon initial turn on.
Mute: The Mute control disables the preamplifier output temporarily. Press it once to mute, and again to restore the volume. When the sound is muted, the light in the volume indicator will flash. Mute is independent for each zone when Zone 2 is also active.
Polarity : The Polarity control inverts the polarity of the entire system. While the Relentless Preamplifier does not invert polarity, many source devices do, and many recordings are produced with inverted polarity. Because there is no way of knowing what the proper polarity is, this must be set by ear. Push the Polarity button on the front panel to invert the polarity. The lights on the preamplifier’s front dial will turn from green to red when the polarity is inverted. Try listening with the polarity normal or inverted, and use whichever setting sounds better. Depending on the recording, the effects of polarity inversion are often subtle and sometimes even inaudible.

Zone 1 and Zone 2 operation
The Relentless Preamplifier is a two-source/two-zone preamplifier. This means that two different sources can play simultaneously. The Relentless Preamplifier defaults to Zone 1 operation when the unit is powered up from standby. The active input will only play in Zone 1.

Zone 1 and Zone 2 system example: In this system example, the Momentum Phonostage is the source for Zone 1 with the Relentless Amplifiers powering the Zone 1 loudspeakers. Simultaneously, a streaming source is the Zone 2 source using the Optional Digital Streaming Module with the Momentum M400 amplifiers powering the Zone 2 loudspeakers.

To play the same source in Zone 1 and Zone 2 simultaneously: Press the Zone 2 button and press the same input button that is active for Zone 1. The top chassis volume control functions as the Zone 1 volume control and the meter illumination remains green. The bottom chassis volume control now functions as the Zone 2 volume control and the meter is illuminated in a lighter green.

To play a different source in Zone 1 and Zone 2: Press the Zone 2 button and press a different input button for Zone 2. The Zone 2 input button will be green. The top chassis volume control functions as the Zone 1 volume control and the meter illumination remains green. The bottom chassis volume control now functions as the Zone 2 volume control and the meter is illuminated in a lighter green.

To return to Zone 1 playback only, press the Zone 2 button until the bottom chassis illumination returns to the same lighter green as in the top audio chassis. This will cancel the Zone 2 operation.

Volume: The Relentless Preamplifier features volume controls on both audio chassis. Either volume control may be used to adjust Zone 1 volume. They are synchronized and the needles will move together when either control is used. Turn the ring around the volume indicator clockwise to raise the volume and counterclockwise to lower it. The needle indicators will move toward the right as you increase the volume and to the left as you decrease it. For more precise volume indication, the Relentless Preamplifier includes a numeric volume in the middle of the power supply chassis. This display defaults to illuminated but may turned off from the remote control. The Relentless Preamplifier reverts to volume setting zero when returned to the standby mode or when changing inputs.

Source selection : Push the front panel button that corresponds to the desired source. The LED in the middle of the front panel button (red for Zone 1, green for Zone 2) for the active source will illuminate.
Theater Bypass: Input Three can be set for use as a Theater Bypass input. This feature makes it easy to include the Relentless Preamplifier in a multichannel home theatre audio system. To set Input Three for this operation, press and hold the Input Three button until the numeric display briefly flashes 70. To use this feature, connect the left- and right-channel outputs of the surround-sound processor to the Relentless Preamplifier’s Input Three. When listening/viewing a home theatre source, select Input Three. In this mode, the Relentless Preamplifier’s volume control is bypassed and volume control for the Zone 1 left and right speakers is controlled by the connected surround-sound processor. To return Input Three to standard input, press and hold the Input Three button until the numeric display flashes 00.

Note: When Input Three is set for Theater Bypass, this input cannot be selected for Zone 2 operation.

Remote Control operation

The Relentless Preamplifier Bluetooth® remote control is bidirectional and uses touchpad technology to operate the preamplifier. All front panel operations except activating the Theater Bypass mode are duplicated on the remote control. The remote control also has additional features detailed below.
The preamplifier will automatically pair with the remote control after the initial powering up of the preamplifier. There are no additional steps required. A timer returns the remote control to its sleep mode after one minute of inactivity.
Internal rechargeable batteries power the remote control. To charge the battery, place the remote control on the included wireless charging pad.
A combination of menu and direct buttons guide the operation of the remote control.

Direct buttons
Standby: When the preamplifier is in standby (off) mode, the LED in the middle of the button will be lit. Push the standby button on the touch panel to turn the unit on. When power is on, the LED in the middle of the button will go off and the volume indicator will illuminate. Push the button once more to turn the unit off. The light for the volume indicator will go out and the LED in the middle of the Standby button will light up. The Relentless Preamplifier defaults to Zone 1 and the Zone 1 LED will also illuminate upon initial turn on.

Mute: The Mute control disables the preamplifier output temporarily. Press it once to mute, and again to restore the volume. When the sound is muted, the light in the volume indicator will flash. Mute is independent for each zone when Zone 2 is also active.
Back: The Back button returns the remote to the previous menu screen.
Enter: The Enter button confirms a selection within the menu options.
Right and Left arrows: The arrow buttons move the cursor to the left or right within the menu or operating system.
Volume control: The red ring functions as the volume control on the remote control. Using a finger, circle the ring clockwise to raise the volume and counterclockwise to lower it.
Remote Control only settings
Balance: The Balance control lets you shift the stereo balance to right or left. To activate it, navigate to the Balance button on the remote. The volume indicator on the face of the preamplifier will swing to show the current balance setting. Use the arrow keys or the volume ring to change the balance setting. If the needle points straight up, the balance is even between left and right. If the needle points to right or left, the balance is shifted to that side. To return the balance to the centre, hold down the Balance button for two seconds. The meter backlight will flash to indicate the reset, and the needles will return to the centre.
Gain adjustment: The Relentless Preamplifier can be set for +8 dB or +14 dB gain. The extra volume provided by the latter setting may be needed to achieve a sufficient output level with a power amplifier that has a relatively low gain. The default setting is +8 dB. To switch to +14 dB gain, navigate to the more button and then the menu option that says gain and press enter. Use one of the arrow keys to toggle between +8 and +14 dB. The numeric display will briefly show LO or HI when a gain adjustment is made.
Dark Mode: Dark Mode blanks out the volume control meters and LEDs after 15 seconds of illumination. To engage the Dark Mode, navigate to the More button, press enter and then navigate
to the Dark Mode button. Select the desired option and press enter. The numeric display will briefly show DM when placed into this mode.
Numeric display: The numeric volume display in the middle of the power supply chassis provides a precise display of volume shown in the meter displays. This display defaults to the illuminated mode. If desired, this display can be turned off. To change the setting, press the More button, navigate to the display button and select the setting to the desired option.

DIGITAL STREAMING MODULE (DSM)

Network connection
The Relentless Preamplifier needs to be connected to a router with internet connectivity using a wired or wireless connection to take advantage of all the features of the Dan D’Agostino Relentless Preamplifier app. Through the app, access to your NAS-stored music files and streaming services including Spotify, Tidal, and Qobuz may be accessed.

To link the Relentless Preamplifier to a network, connect the network cables from the router to the RJ45 connector on the back of the Relentless Preamplifier. The Dan D’Agostino App will now recognize the Relentless Preamplifier and provide access to all network-connected drives as well as the included online streaming services. We recommend using the hard-wired Ethernet connection, though it is
not required.
For systems that do not have access to a wired connection, Wi-Fi operation is available. To connect, ensure the Wi-Fi antenna included in the Relentless Preamplifier shipping case is connected.
Press and hold the Mute button on the front panel of the unit for 5 seconds or until the Relentless Preamplifier appears as a Wi-Fi network on your iOS device. Additionally, the numeric display will briefly show n, the abbreviation for network. Select this network—the password is password. Open the Relentless Preamplifier app and select device setup under the gear ( ) icon. Select the Relentless Preamplifier and then the Wi-Fi Network Selection. Choose the home network, enter the password, and join the connected network. After entering the password for the home network, a message will appear on the screen, indicating a pending connection to the home network. The Relentless Preamplifier will now appear on the Play To screen. Select the Relentless
Preamplifier and music will now be sent to the Relentless Preamplifier for playback.
Note: The Network input must be selected on the Control Screen ( ) for streaming internet, cloud, or network music. The Relentless Preamplifier will automatically switch to the Network input when the play button is pressed on streaming, cloud, or network music.

Basic setup for use with Digital Streaming Module

While you can use the Relentless Preamplifier on its own for use with analog sources, an iOS device is required to take advantage of the digital functionality. Download the free Dan D’Agostino app, Relentless Preamplifier from the Apple Store. Once the app is installed, you can launch it from the phone or tablet by tapping on the Dan D’Agostino Master Audio System’s icon.
The settings page is accessed via the upper left gear icon ( ). Network, cloud, and app setup are available in this area. In the upper right corner is a 3-slider icon ( ) which opens the control page to select source inputs and additional preamplifier functions.
Press the gear button on the upper left to access the settings page. If using a Wi-Fi connection, it will only be necessary to select the network and enter a password. This step is not required if using a hard-wired Ethernet connection.

DIGITAL INPUT SELECTION FROM THE FRONT PANEL

Upon installing the optional Digital Streaming Module in the Relentless Preamplifier, Input 5 serves as the control for digital inputs. A single press of the Input 5 button maintains the selection of the balanced analog input. For activating the digital inputs, press and hold the Input 5 button. This action results in the illumination of Inputs 1-3 in red and Input 4 in green, signifying the active network input. To revert to analog operation, press and hold the Input 5 button once again.

Press the Input 1 button to select the Optical Digital input.
The numeric display will briefly show O, the abbreviation for an optical input.
Press the Input 2 button to select the coaxial digital input.
The numeric display will briefly show C, the abbreviation for the coaxial input.
Press the Input 3 button to select the coaxial digital input.
The numeric display will briefly show U, the abbreviation for the USB input.
Press the Input 4 button to select the network digital input.
The numeric display will briefly show S, the abbreviation for the streaming input.
Press and hold the Input 5 button again to return to the analog Input 5 source The numeric display will briefly show A, the abbreviation for the analog input.

If an analog input is then selected, the next time the Input 5 button is pressed and held, the network input, Input 4, will be activated.
Note: All digital inputs are directly accessible when using the iOS Relentless Preamplifier App or Remote Control.

Using the Relentless Preamplifier with Roon
The Relentless Preamplifier is Roon-ready. You will need a Roon account and the Roon Core installed on your NAS or connected computer. Being Roon Ready means that the Relentless Preamplifier uses Roon streaming technology, for an incredible user interface, simple setup, rock-solid daily reliability, and the highest levels of audio performance, without compromise. The Roon remote can now be used to manage your network, Tidal, and Qobuz music playback. See Roonlabs.com for more information.

Operating the Relentless Preamplifier via the app
The app allows control of all the basic and advanced functions of the unit.

Player screen
When you enter the app, the player screen will appear. The player page includes music transport controls, standby, balance, and access to other screens. Cover art replaces the D’Agostino logo when a music file is selected.

Volume: To adjust the Relentless Preamplifier’s volume, move the slider to the right to raise the volume, or left to lower the volume.

Control screen
Press the ( ) button to access the Control screen.

Standby: This button changes the unit for the power on to standby and the reverse.

Zone 1 and Zone 2 : The Relentless Preamplifier defaults to Zone 1 and the Zone 1 button will illuminate on the app. To control Zone 2, press the Zone 2 button and then all unit controls will be for Zone 2 operation. Press the Zone 1 button to return to Zone 1 control.

Balance: Move the slider to the left to adjust the balance to the left and move the slider to the right to move the balance to the right. Press the word balance to restore centre balance.

Source Selection : Press one of the input buttons (Analog inputs 1-5, Coaxial, Optical, USB, or Network) to select these sources. For network-based and internet listening, first select the Network input. Press the Stream button to access network-based and Internet sources, such as Spotify, Tidal, Qobuz, and NAS drives.

Optical: Press this to use the Toslink optical digital input on the back of the Relentless Preamplifier.

Coaxial: Press this to use the SPDIF coaxial digital input on the back of the Relentless Preamplifier.

USB: Computers can be connected using a USB-A male-to-USB-B male cable. The USB-A connector is connected to the computer’s USB jack and the USB-B connector is plugged into the USB input. The USB input is selected by pressing the USB input selector button on the app. Operation is automatic when connecting Apple computers running macOS to the digital module. When using a computer running Windows OS, bridging software and Windows driver software will need to be installed. A simple solution when using a Windows PC is to install the Roon Labs music player software (subscription required) and the digital module’s Windows driver. JRiver software is also a good option when using a Windows PC. Please visit the Relentless Preamplifier product page at www.dandagostino.com for additional information on connecting a Windows PC to the Relentless Preamplifier and to download the required Windows driver.

Polarity: Press the Normal or Inverted button to flip the system’s absolute polarity. There is no “right” setting; it varies from recording to recording. Use the setting that sounds better on the recording currently playing.

Dark Mode: These buttons dim the Relentless Preamplifier’s front meters after some time for listeners who prefer a dark environment.
The bottom row of the Player page includes queue control, favourites selections, stream options, and play-to choices. The stream option opens the page that reveals the Internet streaming sources, cloud and network drives that the Relentless Preamplifier can access in the connected system (see below).

Stream screen
The Stream screen is divided into three sections. The items on this screen will reflect the makeup of a particular system.

Internet Music: Accesses the various Internet-based and wireless sources that the Relentless Preamplifier can access. Subscriptions are required for these services.

Cloud: This section displays the cloud-based locations that have been configured for music storage. For more information, please contact your dealer.

Local Server: Displays local networked computers and hard drives through
DLNA. For more information, please contact your dealer.

Note: The network input will automatically be selected when any of the streaming sources and music is selected for playback, and has to be selected first on the Control Screen before selecting one of the streaming sources on the Stream Screen.

Play To screen
Once a network source is chosen, press the Play To button and select the Relentless Preamplifier from the list presented. The items on this screen will reflect the makeup of a particular system.

Queue and favourites screens

Queue lists the current music selection being played from network storage locations.
Favorites allows you to organize your network stored music into favorite folders and playlists.
Streaming music services have their own specific queue and playlist functions.

MAINTENANCE

The Relentless Preamplifier requires no user maintenance other than to keep it clean and ensure that the vents remain unobstructed.
The Relentless Preamplifier has a fine, highly polished finish that can be easily damaged. To clean the preamplifier, spray a small amount of distilled water onto the supplied microfiber cloth and gently wipe the preamplifier’s surface along the direction of the metal grain, with light pressure only. Never use a circular motion or heavy pressure, as this can permanently scratch the machined surfaces. Do not rub the surface with the cloth, and do not spray any liquid directly onto the preamplifier.
If dust or other contaminants or objects collect around the vents at the top and bottom of the preamplifier, remove small objects by hand and use a shop vacuum or hand vacuum to remove the dust. Use a brush attachment on the vacuum to avoid scratching the preamplifier’s surface.
If you should need to transport or ship the preamplifier, be sure to use the original packing materials. Allow the preamplifier to cool down for at least one hour before you wrap and package it.

TROUBLESHOOTING

The preamplifier will not power up
If the front meters are not illuminated, follow the procedure outlined below. If one step succeeds in activating the power, stop there and ignore the other steps.

If the LED in the middle of the Standby button on the front of the preamplifier is lit, push the button to turn the preamplifier on.
If the LED in the middle of the Standby button is not lit, check to make sure the AC cord is plugged into the wall outlet.
Check at the back of the power supply to make sure the 15-amp IEC connector is pushed into the jack on the back of the power supply.
Check to make sure the three units are securely connected via their locking feet.
Open the fuse connector integrated into the power switch on the back of the power supply. Check to see if the fuse is blown. (The conductor inside the fuse will be severed and you may see burn marks on the fuse.) Be sure to replace the 10A fuse with one of the proper values. Consult your dealer or Dan D’Agostino Master Audio Systems, LLC.
Check your household electrical box to make sure the circuit breaker has not been tripped. If it has, flip the breaker back on.
If the breaker trips again, check the speaker cable connection on your amplifier and the speaker to make sure that the terminals are not shorted and check the entire length of the cable to ensure there has been no damage to it.
If all of these steps fail to return power to the preamplifier, consult your dealer for service.

Front indicators are illuminated but you hear no sound
Follow these steps in order. If one step succeeds in restoring the sound, stop there and ignore the other steps.

Check your amplifier and source device to make sure they are both turned on.
Check the source device to make sure it is playing, and that the correct input is selected on the preamplifier.
M ake sure the preamplifier is not muted. If the displays are flashing, the preamplifier is muted. If the displays are flashing, the preamplifier is muted. Press the front panel or remote control mute button to disengage the remote.
Check the line-level connections between the source device and the preamplifier
and between the preamplifier and the amplifiers. Reconnect any cables that may have become disconnected.
Check the cables between the amplifiers and the speakers to make sure they are properly connected and that the cables have not become damaged.
Substitute an alternative set of interconnect cables between the source device and the preamplifier and between the preamplifier and the amplifier. If this restores sound, replace the defective cables.
If all of these steps fail to restore sound, consult your dealer for service.

Sound comes from only one channel
Follow the below steps in order. If one of these steps succeeds in restoring the sound, stop there and ignore the other steps.

Push the Balance button on the remote to see what the balanced setting is. If the needles on the front dials are moved to one side or the other, hold the Balance button on the remote down for 2 seconds. The needle will return to the center as will the sound.
Check the interconnect connections between the source device and the preamplifier and between the amp and preamplifier to make sure all cables (and XLR-to-RCA adapters, if you’re using them) are securely connected.
Check speaker cable connections for the malfunctioning channel. Reconnect any cables that may have become disconnected. Inspect the cable to make sure it has not been damaged. If it has been damaged, replace it.
If you are using monoblock amplifiers, such as the Relentless Amplifier, make sure both amplifiers are turned on.
Swap the left-channel interconnect cable from the preamplifier to the amplifier with the right-channel interconnect cable. If the malfunctioning channel now works but the other channel does not replace the defective interconnect cable with one of the same types. You may have to replace both right and left cables to make sure they match.
Swap the left-channel interconnect cable from the source device to the preamplifier with the right-channel interconnect cable. If the malfunctioning channel now works but the other channel does not replace the defective interconnect cable with one of the same types. You may have to replace both the right and left cables to make sure they match.
Try using a different source device. If the alternate source device delivers sound in both channels, it is likely the source device is defective. Consult the manufacturer of that source device or your dealer for further information.
If possible, try using a different amplifier. If the alternate amplifier delivers sound in both channels, it is likely the original amplifier is defective. Consult the manufacturer of the amplifier or your dealer for further information.
If all of these steps fail to restore sound, consult your dealer for service.

Preamplifier functions but the remote control does not
Follow these steps in order. If one step succeeds in restoring the operation of the remote, stop there and ignore the other steps.

Make sure the Relentless Preamplifier remote is charged. Place the remote on the included wireless charger to recharge the batteries.
Check to make sure the Bluetooth® antenna is securely fastened to the back of the Relentless Preamplifier.
If these steps fail to restore the operation of the remote, consult your dealer.

WARRANTY

RELENTLESS PREAMPLIFIER LIMITED WARRANTY
Dan D’Agostino Master Audio Systems, LLC warrants the Relentless Preamplifier against manufacturing defects and defects in materials for five years from the date of purchase or six years from the original date of shipment from Dan D’Agostino Master Audio Systems, LLC from an authorized Dan D’Agostino Master Audio Systems dealer, subject to the conditions listed below:

The warranty covers only new products purchased from an authorized Dan D’Agostino Master Audio Systems, LLC dealer.
The warranty is non-transferable and is valid only for the original purchaser.
The warranty is valid only if the product has been used according to the instructions in the owner’s manual. Damage due to accidents or owner abuse or neglect is not covered under this warranty.
All service must be performed by an authorized Dan D’Agostino Master Audio Systems dealer. Damage resulting from service by other parties is not covered under this warranty.
All products returned for service must be packaged in the original container and must include a photocopy of the original purchase receipt. If the original container has been lost or discarded, contact Dan D’Agostino Master Audio Systems, LLC for a replacement.
If the product must be shipped back to Dan D’Agostino Master Audio Systems, LLC for warranty service, the customer shall pay shipping costs. Dan D’Agostino Master Audio Systems, LLC will pay for return shipping.
Before shipping the product to Dan D’Agostino Master Audio Systems, LLC for service, the customer must first obtain a Return Authorization (RA) number by calling Dan D’Agostino Master Audio Systems, LLC. The RA number must be marked clearly on the side of the package.
This warranty covers only defects in products made by Dan D’Agostino Master Audio Systems, LLC. It does not cover incidental or consequential damages, or damages to other products resulting from defects in Dan D’Agostino Master Audio Systems, LLC products.
U.S. residents: Depending on which state you live in, you may have other rights not elaborated in this document. For further information, contact Dan D’Agostino Master Audio Systems, LLC.
Residents of other countries: Your authorized importer or dealer bears the direct responsibility for warranty coverage of your preamplifier. Please contact your importer or dealer with requests for service under warranty. Dan D’Agostino Master Audio Systems, LLC will work with your importer or dealer to ensure that the terms of the warranty are fulfilled.

For questions on warranty and service matters, contact Dan D’Agostino Master Audio Systems, LLC at:
+1.480.575.3069 or service@dandagostino.com

SPECIFICATIONS

Frequency response 0.1 Hz to 120 kHz, +/- 0dB : Distortion <0.006%, 20 Hz to 20 kHz
Signal-to-noise ratio: -105 dB, unweighted-100 dB, weighted
Gain: +8 or +14 dB, switchable
Inputs : 5 balanced XLR stereo
Outputs: Zone 12 pairs balanced XLR stereo: Zone 2 1 pr balanced XLR stereo
Dimensions (audio chassis) 17 x 3.9 x 17 in (whd) 43.2 x 9.9 x 43.2 cm (whd)
Dimensions (power supply) 17 x 3.9 x 17 in (whd) 43.2 x 9.9 x 43.2 cm (whd)
Dimensions (stacked) 17 x 13.75 x 17 inches (whd) 43.2 x 34.9 x 43.2 cm (whd)
Total weight (combined): 132 lb/60 kg