Margules SF220-20th User manual

SF220-20th
Audio
preamplifier

IMPORTANT SAFETY INSTRUCTIONS
CAUTION: To reduce the risk of electric shock, do not
remove the cover. There are no user-serviceable parts
inside; it is recommended that only qualified personnel
service this component.
1. OWNER’S MANUAL: Before powering up the
equipment, read all safety and operating instructions and
follow them as instructed. Retain the safety and operating
instructions for future reference.
2. ATTACHMENTS: Use only those attachments
recommended by the unit manufacturer, as others may
cause hazards.
3. ACCESSORIES: Do not place the unit on an unstable
cart, stand, tripod, bracket, or table. The unit may fall,
causing injury to a person or damage to the unit. Mount
the unit according to the manufacturer’s instructions with
the suggested mounting accessory.
4. WALL OR CEILING MOUNTING: Mount the unit to a
wall or ceiling only in the manner recommended by the
manufacturer.
5. WATER AND MOISTURE: Do not use the unit near
water (for example, near a swimming pool, bath tub,
wash bowl, kitchen sink, or laundry tub) or in a damp
environment (like a basement or outside in the rain).
6. OBJECT AND LIQUID ENTRY: Do not push objects of
any kind into the unit through openings as they could
touch dangerous voltage points and short-out parts,
possibly resulting in a fire or electric shock. Avoid spilling
liquid of any kind on the unit. If water or any metal object
(such as a paper clip, coin, or staple) accidentally falls
inside the unit, disconnect it from the AC power source
immediately and contact Margules Audio for further
instructions.
7. HEAT: Position the unit away from heat sources such
as radiators, heat registers, stoves, or other units
(including amplifiers) that produce heat.
8. VENTILATION: Slots and openings in the cabinet
create ventilation to protect the component from
overheating. Allow at least 6 inches (16cm) of clearance
above the unit and an opening behind the unit for airflow.
Do not place the unit on a bed, sofa, rug, built-in
bookcase, or rack without adequate ventilation.

9. GROUNDING OR POLARIZATION: As a safety
feature, the unit may be equipped with a polarized
alternating current line plug in which one blade is wider
than the other. This plug will fit into the power outlet only
one way. If you cannot insert the plug fully into the outlet,
try reversing the plug. If the plug still will not fit, contact a
licensed electrician to update your obsolete outlet. Do not
defeat the safety purpose of the polarized plug.
10. POWER SOURCES: Operate the unit only from the
power source indicated on the marking label. If you are
unsure of the type of power supplied to your home,
consult your unit dealer or local power company.
11. POWER CORD PROTECTION: Arrange power
supply cords so that they do not suffer from foot traffic or
pinching by items placed on or against them. Pay close
attention to cords where plug enter the AC outlet and
where they exit from the unit.
12. LIGHTNING: For added protection during a lightning
storm or when the component is idle for long periods of
time, unplug the unit from the wall outlet and disconnect
the antenna or cable system. This will help protect the
unit from lightning and power line surge damage.
13. POWER LINES: Do not locate an outside antenna
system in the vicinity of overhead power lines or other
electric light or power circuits. When installing an outside
antenna system, take extreme care to avoid touching the
power lines or circuits; contact with them could be fatal.
14. OVERLOADING: Do not overload wall outlets,
extension cords, or integral convenience receptacles as
this increases the risk of fire or electric shock
15. REPLACEMENT PARTS: When replacement parts
are required, be sure the service technician has used
replacement parts specified by the manufacturer or those
having the same characteristics as the original parts.
Unauthorized substitutions may result in fire, electric
shock or other hazards.
16. SAFETY CHECK: Upon completion of any service or
repairs to the unit, ask the service technician to perform
safety checks to ensure the unit is in proper operating
condition.
17. IMPORTANT SAFETY NOTE:
• Before connecting a new product such as the SF220 to
your audio or home theater system, turn off all other
equipment (preferably unplugging them from the AC
power source). Many audio components feature
automatic turn-on circuits that may activate during an
installation, potentially causing damage to electronic
components and/or speakers. This type of damage is not

covered by product warranties, and Margules Audio
specifically disclaims responsibility for any such damage.
• Power Cord: The removable power cord provided with
your player was specifically designed for use with this
product, but other AC cords may be used. Consult your
dealer for advice on AC power cords and high quality wire
in your system.
• AC Fuse: The fuse is located inside the
chassis and is not user serviceable. If the
unit does not power up, contact an
authorized service representative
• Wiring: Cables running inside walls should have the
appropriate markings to indicate compliance and listing
by the UL, CSA or other standards required by the UL,
CSA, NEC or your local building code. Questions about
cables inside of walls should be referred to a qualified
custom installer, a licensed electrician, or low-voltage
contractor.
18. RECORDING COPYRIGHT: Recording of
copyrighted material for other than personal use is illegal
without permission of the copyright holder.
19. NOTE TO CATV SYSTEM INSTALLER: This
reminder is provided to call the CATV system installer's
attention to article 820-40 of the NEC, ANSI/NFPA 70,
which provides guidelines for proper grounding and, in
particular, specifies that the cable ground shall be
connected to the grounding system of the building as
close to the point of cable entry as practical.
20. FCC INFORMATION FOR USER:
• CAUTION: Any changes or
modifications not expressly approved
by Margules Audio could void the
user's authority to operate the equipment.
• NOTE: This equipment has been tested and found to
comply with the limits for a Class B digital device
pursuant to Part 15 of the FCC Rules.
• These limits are designed to provide reasonable
protection against harmful interference in a residential
installation. This equipment generates and can radiate
radio frequency energy, and if not installed and used in
accordance with the instructions it may cause harmful
interference to radio communications. However, there is
no guarantee that interference will not occur in a
particular installation. If this equipment does cause
harmful interference to radio or television reception,
which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the
interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and
receiver.
• Connect the equipment into an outlet on a circuit
different from where the receiver is connected.
21. OUTDOOR ANTENNA INSTALLATION/SAFE
ANTENNA AND CABLE CONNECTION:
• If an outside antenna or cable system is connected to
the equipment, be sure the antenna or cable system is
grounded in order to provide protection against built-up
static charges and voltage surges. Article 810 of the
National Electrical Code, ANSI/NFPA 70 (in Canada, Part
1 of the Canadian Electrical Code) provides information
regarding proper grounding of the mast and supporting
structure, grounding of the lead-in wire to an antenna
discharge unit, size of grounding conductors, location of
antenna discharge unit, connection to grounding
electrodes and requirements for the grounding electrode.
• Outside antenna system should be located well away
from power lines, electric light or power circuits and
where it will never come into contact with these power
sources if it should happen to fall. When installing an
outside antenna, extreme care should be taken to avoid
touching power lines, circuits or other power sources as
this could be fatal. Because of the hazards involved,
antenna installation should be left to a professional.

INTRODUCTION
Congratulations!
You have purchased a legendary audio product that
brings you both the superior sound of vacuum tubes and
state of the art technology; learned over the past 20+
years of product development. The SF220 will bring you
long hours of listening enjoyment. A truly TANGIBLE
MUSICAL EXPERIENCE.
Vacuum tube preamplifier SF220
The Margules SF220 series combines the superior sound
of vacuum tubes with innovative circuitry that pushes
design boundaries. The result is exceptionally good
sound and unusual versatility.
Low impedance
The SF220's output stage is a very-low-impedance
design that can drive virtually any cable or power
amplifier without audible interaction or loss of sound
quality. The SF220's wide frequency response is
maintained even with long cable runs, so there is no
softening or loss of detail.
The SF220's advanced design is complemented by the
use of premium components. The PC board is silver-
plated for maximum conductivity.
The SF220 is clean and effortless-sounding that it brings
out the best in any power amplifier, even solid-state
models that sound constricted or edgy with other
preamplifiers.
Shunt Regulated Power Supply
The power supply is located in a separate chamber within
the chassis of the preamplifier to avoid noise induction.
On board the SF220 there is SHUNT power supply for its
high voltage circuits. Shunt technology provides a
dramatic improvement in Q damping, the key factor in
regulating voltage for those stages. Good regulation
reduces the loss of signal integrity that occurs when the
signal itself shifts the amplifier’s operating point. Damping
is critical to overall performance including smoother
transient response and overall staging. Further
improvements in quickness, dynamics and the overall life-
like listening experience result.
Our new Power Supply is virtually indestructible due to
specially designed regulation technology that protects the
amp from major tube failures.
The filament supply is DC (not AC) for minimum hum. It is
fully regulated as well.

Active filament damping
To minimize the microphonics effect produced by the
tubes, the SF220 has a circuit that actively damps the
filament.
Remote control
The SF220 has a microprocessor controlled remote
control that with RS232 connection can be controlled by
any automation system. This connection is an optional
feature.
All the functions of the SF220 on the RS232 port are
discreet, including the ON and OFF.
The supplied IR remote control has discrete functions
except the ON/OFF, which is toggle.
Connections
IMPORTANT: The AC Power supply should be the last
connection made.
The SF220 is a preamplifier with unbalanced inputs and
outputs. All its inputs have the same impedance and gain,
and any line level signal (.6 to 5 Volts) can be connected
into as required (4). For the interconnections between
your audio inputs, the preamplifier and the amplifier see
the figure 2.
The SF220 has a direct input. This connection bypasses
the volume control, so the SF220 can be controlled by an
external processor or preamplifier. The SF220 along with
a 5 channel system then integrates a High End two
channel preamplifier with a surround system (3).
The two outputs of the SF220 are in parallel so any set
can be used. For example, they can be used by the main
amplifier and the subwoofer (1).
The direct output is not “pre-amplified”; it does not go
through the SF220. The output is set by the input
selection made in the preamplifier. Therefore its volume
is not controlled, if a low impedance device is connected
into it.
Be advised, the level and sound characteristics of the
SF220 can change if a low input impendence device is
connected to it.

The AC outlet is a high current output (600 Watts) and is
energized when the preamplifier is ON. This outlet is
designed so the remote control can turn the unit ON and
OFF. In addition, a line noises suppressor (like the
Magenta QR1 or QR2) or any device that wants to be
switched ON and OFF with the remote control, can utilize
this function. This is ideal for integrated systems (6). If
you have a line noise suppressor and you want to do this
configuration, go to figure 3.
When the SF220 is connected to AC supply the filaments
will light on and will remain lighted until is disconnected.
This is to extend the tube life expectancy avoiding
applying the high voltage to the tube while the cathode is
cold.
Having the filaments on is the standby mode.
Controls
The SF220 is designed to be easy to navigate; all the
main functions can be activated by the remote control or
the buttons and knob in the unit.
All the main discreet functionality is accessible from the
remote control unit.
On the front panel the SF220 has a big volume knob and
the IR sensor (8). On the rear panel there are two
buttons; one is a toggle ON/OFF switch and the other is a
sequential input selector (5).
Connecting the SF220 to an automation system
In the rear part there is a serial RS232 connection port
with 2 way communication. This feature is for integrating
the SF220 to an automation system.
If you want to control it by itself it, can be connected to a
web server (not included).
The RS232 Code are:
Selection: !1ENT01 !1ENT02 !1ENT03 !1ENT04
Direct input: !1ENT05
Mute: !1ENT06
Volume change
UP !1VOL99
Down ! 1VOL55
Power OFF ! 1PWR0
Power ON !1PWR1
Toggle ! 1POW2

Figure 1. Front and back of the SF220

Figure 2. Interconnection
between the SF220 and U280
Figure 3. Integrated system with line noise suppressor

Characteristics:
Frequency response: 5-400 khz
Total harmonic distortion: <0.014% max
Maximum output level: 30 V
Signal to noise ration: >80db
Gain: 6 dB
Raise time: 6 micro sec.
Fall time: 6 micro sec.
Power consumption (max): 55 w
Weight: 14kg
Dimensions (height, width, depth):
13.6 cm x 44cm x 3 cm
WARNING
Electrical hazard! Misuse or failure to follow
instructions properly may result in personal
injury or death!
CAUTION
No risk or personal injury; however, misuse
or failure to follow instructions may result
in damage to equipment.
NOTE
No risk or personal injury or equipment
damage; however, misuse or failure to
follow instructions may prevent proper
performance of the equipment.

LIMITED WARRANTY
What is covered and what is Not Covered
Except as specified below, this warranty covers parts and
labor to correct all defects in materials and workmanship.
The following are not covered by the warranty:
1. Damage, deterioration, malfunction or failure to meet
performance specifications resulting from:
a. Accident, acts of nature, misuse, abuse, neglect
or unauthorized product modifications
b. Improper installation, removal or maintenance,
or failure to follow instructions supplied with the
product.
c. Repair or attempted repair by anyone not
authorized by Margules Audio to repair the
product.
d. Any shipment of the product (claims must be
presented to the carrier).
e. Any cause other than a product defect.
2. Cleaning, initial set-up, check-ups with no defects
found, or charges incurred for installation, removal or
reinstallation of the product.
3. Any product, on which the serial number has been
defaced, modified or removed.
4. Accessories, including but not limited to, batteries,
cables, mounting hardware and brackets, cleaning
accessories, antenna and detachable power cords.
5. Warranty is void if purchase was made from anyone
other than an authorized Margules Audio dealer.
Who May Enforce the Warranty?
This warranty extends to products purchased directly
from Margules Audio or an authorized Margules Audio
dealer. Purchasers should inquire of the dealer regarding
the nature and extent of the dealer’s warranty, if any.
What Will We Pay For?
We will pay for all labor and material expenses for items
covered by the warranty. Payment of shipping charges is
discussed in the next section of this warranty
How You Can Get Service?
In the event that the owner needs to return the unit to
Margules Audio for service or repair of a possible defect,
he must do the following:
Contact Margules Audio at [phone] in Mexico or
at 707-5811830 in USA and ask for technical support.

Or visit Margules Audio at the address in the end
of this manual with your product. If you want to
send it the cost is on your account.
Limitation of Implied Warranties
All implied warranties, including warranties of
merchantability and fitness for particular purchase, are
limited in duration to the length of this warranty.
Exclusion of Damages
Margules Audio’s liability for any defective product is
limited to repair or replacement of the product at
Margules Audio’s option. Margules Audio shall not be
liable for damage to other products caused by any
defects in Margules Audio products, damages based
upon inconvenience or loss of use of the product, or any
other damages, whether incidental, consequential, or
otherwise.
How State Law Relates to the Warranty
Some states do not allow limitations on how long an
implied warranty lasts and/or do not allow the 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.
MARGULES GROUP MEXICO SA DE CV
Uruapan #17-4, Col. Roma
Mexico D.F. 06700
Mexico.
Tel. [phone]
Toll free 1-888-538 8605
FAX [phone]
Email: [e-mail]
MARGULES USA
820 Elm Drive/div. PetalumaCA, 94952
Phone number:
707-5811830
Collect USA & Canada:
1-888-538 8605
Fax number: 707-5811830
Visit our home page in internet:
http://www.margules.com