AGD Alto User manual

AGD Productions, Inc.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 1 of 24

AGD Productions, Inc.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 2 of 24

AGD Productions, Inc.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 3 of 24
AGD “Alto”Reference Preamplifier
by AGD Productions, Inc.
Operating Manual
Rev.01
Document Date, January 18th, 2022
CAUTION
THE UNIT CONTAINS NO USER SERVICEABLE PARTS.
DO NOT REMOVE THE PANELS OR ANY SCREWS OR CONNECTORS.
DO NOT OPERATE THE UNIT WITHOUT THE GLASS TUBE FULLY INSERTED
IN THE PROPER SOCKET.
DO NOT OPERATE THE UNIT IF WET OR NEAR WATER OR IN
UNCONTROLLED OUTDOOR CONDITIONS.
BE CERTAIN TO INSTALL IT IN A SECURE LOCATION FROM WHICH IT
CANNOT FALL OR TIP OVER.
TIME SPENT FAMILIARIZING YOURSELF WITH THIS MANUAL WILL BE
WELL REWARDED.

AGD Productions, Inc.
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TABLE OF CONTENT
1. About this document .....................................................page 5.
2. Letter from AGD Team...................................................page 6.
3. Important Safety Instructions........................................page 7.
4. Introduction ...................................................................page 8.
5. Main Features ................................................................page 9.
6. Unpacking the AGD ALTO ..............................................page 10.
7. Installation of the AGD ALTO ......................................... page 11.
8. Front Panel Functions and Operation............................ page 13.
9. Back Panel Connectors...................................................page 14.
10. AC Power Entry module.................................................page 16.
11. Operation.......................................................................page 17.
12. Remote Control Operation ............................................page 18.
13. Troubleshooting.............................................................page 19.
14. Specifications .................................................................page 22.
15. CE and FCC Certification.................................................page 23.

AGD Productions, Inc.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 5 of 24
1- ABOUT THIS DOCUMENT
This Owner’s Manual covers unboxing of, familiarization with, and
configuration of your new amplifier. This manual will enable you to
expertly tailor the behavior and performance of your preamplifier to fit
your preferences of your equipment and listening room.
This user manual is integral part of the AGD “ALTO”and must be
available and consulted prior the installation of the equipment.
The AGD “ALTO”is designed to operate indoor and must be utilized
uniquely for the scope of audio signal amplification within the
specifications and conditions defined in the manual.
It is strongly recommended that you follow this manual in the order in
which it is written so that you understand the safety considerations
before configuring the unit.

AGD Productions, Inc.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 6 of 24
Dear Customer,
I have always been driven by my passion to merge perfection and
beauty in the art of Audio reproduction.
After the launch of the AGD “TEMPO” we wanted to create a
perfect companion preamplifier and so, the AGD “ALTO” is our
new compact reference analog preamplifier.
Crafted with the same care and dedication as all AGD products,
the “ALTO”is a superior musical preamplifier that incorporates all
the design features already adopted in the bigger sibling, the AGD
“Andante”.
The Phono stage, a full balanced topology, has superior
performances that will satisfy the most demanding Audiophile.
While The “ALTO” is by design the perfect companion preamplifier
for our “TEMPO”and “Audion”Stereo GaN Amplifier, it will also
deliver the most sublime and purest sound with any audio systems
of any standard.
The AGD Audio Design team is confident the “ALTO”will meet
your expectations and as a team we will always stand in support of
your needs and future requirements.
Sincerely
Alberto Guerra
CEO, AGD Productions, Inc.

AGD Productions, Inc.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 7 of 24
3- IMPORTANT SAFETY INFORMATION
READ ALL INSTRUCTIONS: All the safety and operating instructions of
your AGD ALTO PREAMPLIFIER should be read before power is applied
to the equipment.
RETAIN OWNER'S MANUAL: These safety and operating instructions should be
retained for future reference.
READ WARNING: All warnings on the unit and in the operating instructions should be
adhered to.
FOLLOW INSTRUCTIONS: All operating and use instructions should be followed.
CLEANING: Unplug the unit from the wall outlet and leave for at least 10 min. - make
sure the unit is not hot before you start cleaning. Use dry or damp soft cloth to clean
the surfaces. Do not use corrosive/abrasive spray for cleaning.
VENTILATION: Do not block any ventilation openings. Do not install near any heat
sources such as radiators, heat registers, stoves, or other apparatus (including other
amplifiers). The unit should not be installed in a built-in location such as a bookcase or
rack unless proper ventilation is provided.
GROUNDING: Do not defeat the safety purpose of the grounding-type plug. A
grounding-type plug has two blades and a third grounding prong. The third prong is
provided for your safety. If the provided plug does not fit into your outlet, consult an
electrician for replacement of the obsolete outlet.
POWER CORD PROTECTION: Protect the power cord from being walked on or pinched
particularly at plugs, convenience receptacles, and the point where they exit from the
apparatus.
LIGHTNING: Unplug this apparatus during lightning storms or when unused for long
periods of time.
SERVICING: Refer all servicing to qualified service personnel. Servicing is required
when the apparatus has been damaged in any way, such as if the power-supply cord
or plug is damaged, liquid has been spilled inside the appliance or it has been exposed
to moisture, the appliance does not operate normally, or has been dropped.
DO NOT OPEN THE CABINET: There are no user serviceable components inside this
product. Opening the cabinet may present a shock hazard and any modification to the
product will void your warranty.
WARNING: To reduce the risk of fire or electric shock, do not expose
this apparatus to rain or moisture.

AGD Productions, Inc.
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4- INTRODUCTION
The AGD “ALTO” is a complete audiophile Line and Phono Reference
Preamplifier that delivers a unique set of features and components in a very
compact beautifully crafted single billet aluminum cabinet. With his built-in
fully balanced phono stage (MM & MC), a volume control with the most
thermally stable and high precision resistor ladder circuit, the “ALTO” is by
design the perfect companion preamplifier for our “TEMPO”and “Audion
MkII” power GaN Amplifiers.

AGD Productions, Inc.
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5- MAIN FEATURES
•Fully Balanced Phono preamplifier stage with MM & MC cartridges
support (selection via Menu and Remote control) and with dedicated
ultra-low noise linear power supply and ultra-low noise linear
professional grade amplifiers stage.
•Analog boards fully shielded and separated from digital boards to
deliver the lowest possible noise and prevent any undesired
interference.
•High Dynamic low noise professional grade instrumentational amplifier
stages for the output buffer stage (configurable as bi-amp X-Over upon
request).
•Fully balanced design and full DC coupling (no capacitors in line with
analog signals).
•Three Analog inputs with one input fully balanced (XLR connectors).
•8bit fully balanced passive Ladder volume control.
•Three analog outputs (for multi-amplification solutions.
•1 XLR balanced output (6.4VRMS max)
•2 Single-ended stereo output (low/high pass X-Over customizable)
•Remote control.
•12V output Trigger.

AGD Productions, Inc.
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6- UNPACKING
Unpacking
All AGD products shipping boxes have been specially designed to protect their
contents and special care has been taken to prevent damage under normal
shipping conditions.
When unpacking the product:
•Mishandling should be evident upon inspection of the flight case.
•Carefully remove the component from its packaging and examine it
closely for signs of shipping damage.
•We strongly recommend saving all original packaging to protect the unit
from damage, should you wish to store it or ship it later.
Please check the content of the shipping is complete and all the following
items are included:
1- AGD ALTO Unit
2- Power Cable
3- Remote control
4- Gloves
5- Operating Manual

AGD Productions, Inc.
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7- INSTALLATION
POWER REQUIREMENTS:
The AGD “ALTO” has universal voltage input configuration and can operate
between 90~264VAC 50/60Hz single phase.
A detachable IEC power cable intended for use in the region where the unit is
sold is included.
WARNING: The unit should be operated only at the rated
voltage indicated on the power connector. If you are not sure
what the main voltage supplied to your home is, consult with
your unit dealer.
•Connect the power supply to the power source indicated on the rear panel.
•Avoid power conditioners that float the ground pin.
•ALWAYS connect power cord to component before plugging it into an AC
outlet and make sure that unit's main switch is set to the “OFF” position
before making the final connection.
•For best performance, try to position the power cord away from any input
signal cables if possible.
•Pay close attention to power quality and be aware that different power
cords can alter the sound.
•For initial power-up, operate the main switch located on the back-panel
power entry module.
•BE CERTAIN TO INSTALL THE UNIT IN A SECURE LOCATION FROM WHICH
IT CANNOT FALL OR TIP OVER.
•Do not operate on carpet or any other surface that might block air flow.
•Do not allow the chassis to touch any metal parts, such as the frame of an
equipment rack. This might create a parallel ground path that could
degrade the sound of your system.
•Connect the source's cables to their appropriate inputs.
IMPORTANT: READ THE SECTIONS “BACK PANEL”

AGD Productions, Inc.
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8- FRONT PANEL FUNCTIONS AND OPERATION
All keys of the AGD “ALTO” are touch-sensitive (no mechanical movement)
hence attention to familiarize with their operation is required.
The functions of the left end side switch group are:
Stand-by - Switches the unit from stand-by to operational mode.
Function/Menu selection: sequential rotation of the following:
▪Balance control
▪Selection of the Menu pages
▪Page 1: Phase inverting / Remote control setup / Display
brightness / Phono stage source type - MC or MM
Input Selector
▪Toggles between input sources as follow:
▪PHONO, RCA2, RCA3, XLR
▪Switches back to the home screen if one of the menu pages is
open.

AGD Productions, Inc.
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8- FRONT PANEL FUNCTIONS AND OPERATION
The functions of the right end side switch group are:
Volume up
▪Turn the volume control up by one step
▪Menu navigation (up).
Enter
▪Apply input selection
▪Select highlighted menu item.
Volume Down
▪Turn the volume control Down by one step
▪Menu navigation (down)

AGD Productions, Inc.
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9- BACK PANEL CONNECTORS
ANALOG INPUTS:
The AGD “ALTO” has four different analog inputs.
•All the Analog input connectors are located on the bottom left area of
the back panel.
•Please refers to the above picture to locate their positions and identify
the functionality.
ANALOG INPUTS
•1x Phono Input L-R –Input #1
•2x RCA Single-Ended (Line level) Input # 2 & #3.
•1x XLR balanced level input
Note: A ground screw connection is made available next to the Phono Input
(Analog Input 1). Use this ground binding terminal to secure the
connection of the ground wire from the Turntable.

AGD Productions, Inc.
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9- BACK PANEL CONNECTORS
ANALOG OUTPUTS:
The AGD ALTO has three sets of analog output terminals.
•One pair of XLR (balanced output)
•2 pairs of RCA (single ended outputs).
The ALTO output interface is then capable of driving up to six different
independent amplification channels.
The buffer output stage circuit is designed around a professional grade
operational amplifier ICs with output characteristics capable to drive any
system of amplification thanks to an output impedance of ~50Ωand maximum
voltage swing of 6.4VRMS.
ANALOG OUTPUTS
•1x XLR 1(Balanced Output) Output #1 Full Range
•1x RCA (Single ended output) Output #2 Full Range
•1x RCA (Single ended output) Output #3 HT Pass-Through

AGD Productions, Inc.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 16 of 24
10-AC POWER ENTRY MODULE
AC POWER ENTRY MODULE
AC Power Entry module functions:
The AGD “ALTO” has universal voltage input configuration and can operate
between 90~264VAC 50/60Hz single phase.
A detachable IEC power cable intended for use in the region where the unit is
sold is included.
WARNING: The unit should be operated only at the rated voltage
indicated on the power connector. If you are not sure what the main
voltage supplied to your home is, consult with your unit dealer.
Power
ON-OFF
Switch
Fuse Holder
IEC Power
Cable Input

AGD Productions, Inc.
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11-OPERATION
OPERATION
•After all the connections of the input signals are verified and are correct,
and the power cable is plugged-in, turn the power switch of the back panel
ON. A red light will illuminate. The unit is powered-up.
•Please note that LED lights of the “ALTO” will illuminate the front panel area.
•At this point the unit enters automatically in STAND-By mode.
•To bring the unit in operation mode, touch the “Stand-by” switch.
•Please note it will take 2~3 seconds after turning the main power
on before the front panel touch sensors are operational, including
the stand-by switch.
•Use the “INPUT” selector switch to toggle between input sources
and set the one you will be using by touching the ENTER button.
•The Menu button gives access to the following functions:
Screen 1:
▪Balance control Operation
Screen 2:
▪Output Phase
▪Remote control setup
▪Display brightness
▪Phono stage source select - MC or MM
•BALANCE ADJUSTMENT:
•To shift the Left/Right balance, press Menu once, and use the
navigation keys on the remote or on the front panel to
adjust the balance of the LEFT-RIGHT channels.
•PHONO INPUT
•To select the appropriate setting for the type of the cartridge
mounted on the tonearm (MM - moving magnet or MC - moving
coil), press the MENU function twice to enter the second page of the
menu and select the radio button MM or MC and press ENTER.

AGD Productions, Inc.
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12-REMOTE CONTROL
REMOTE CONTROL FUNCTIONALITIES:
▪All functions of the AGD ALTO are available via Remote control.
▪The “ALTO” is compatible with a standard Apple Remote type, included
with the unit,
▪The Remote control delivered with the unit is already setup to work
with the “ALTO” and does not require any additional setup.
▪By factory settings, the remote keys assignment is as follow:
•The user can reassign each button’s function through the device’s menu as
follow:
▪Touch the Menu button on the front panel twice
▪Select Remote Control Setup and press ENTER
▪Follow the instructions on screen.
▪Once completed, the AGD “ALTO” will restart and apply the new
settings.
▪The Remote control is now re-programmed.

AGD Productions, Inc.
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13-TROUBLESHOOTING
•The unit is designed to prevent damage to itself and associated
components.
•Incorrect operation is sometimes mistaken for malfunction.
•If problems occur, see this section for troubleshooting information.
•If problems persist, contact your authorized AGD Productions’ dealer.
NO POWER
•Examine the power cord to ensure that it is connected to both the AC
mains connector and a working, un-switched, electrical outlet.
•Make sure the nit is powered on with the rear-panel power switch.
Examine the electrical circuit breaker to ensure that power is being
supplied to the electrical outlet to which the amplifier is connected.
•Make sure the light of the ON/OFF switch of the of the AC power
entry module is on.
NO SIGNAL AT THE OUTPUTS
•Examine all audio cables to ensure a solid connection between the
unit and all associated components.
•Examine the speaker cables to ensure a solid connection between the
amplifier and the speakers.
•Make sure that the connected units (CD player, Turntable etc.) are
powered-on.
•Make sure the volume is set to an audible level.
•Make sure every input cable is correctly inserted.
•Make sure the preamp is not muted.
•Make sure all associated components are connected to working
electrical outlets and powered on.

AGD Productions, Inc.
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13-TROUBLESHOOTING
AUDIO HUM
•Disconnect components one at a time to isolate the problem.
•Once the problem is identified, make sure the problematic
component is properly grounded and connected to the same
electrical socket of the AGD “ALTO”.
IF ALL ELSE FAILS…
•Contact your authorized AGD Productions, Inc. dealer and/or
contact AGD Productions Customer Service at
www.AGDproductions.com