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.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 4 of 24
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.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 8 of 24
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.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 9 of 24
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.
AGD ALTO REFERENCE ANALOG LINE AND PHONO PREAMPLIFIER Operating Manual Page. 10 of 24
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