A-Selector Switch - This knob is turned to select an Input (P)
through (S). The Selector Switch is bypassed when the SFL-1 is in
the Direct mode as selected by the Direct/Normal Switch (B).
B-Direct/Normal Switch - When in the DIRECT position, this
toggle switch selects the Direct Input (O) from a preferred
source, allowing the source signal to bypass all unnecessary
control functions. The signal is only affected by the Mute (G),
the Volume Control (H), and the gain stage of the SFL-1. When
in the NORMAL position, all regular functions are in use and
the source is chosen through use of the Selector Switch (A).
C-Tape/Source Switch - When in the SOURCE position, this
toggle switch routes the signal from the Inputs (P) through (S) as selected by the Selector Switch (A) - to the Tape Outputs (M).
Recording is only possible when the toggle is in the SOURCE
position. In the TAPE position, only the Tape Input jacks (N) are
operational, and the tape is then handled as a selected source.
D-Balance Control - This knob controls the relative balance of
the left and right channels to compensate for any discrepancies
caused by speaker placement, source imbalance, etc. The
Balance Control is bypassed when the SFL-1 is in the Direct
mode as selected by the Direct/Normal Switch (B).
E- Power Indicator LED - This LED lights when the Preamplifier
is receiving power from an AC source. It will flash at one second intervals during warmup delay and muting. After a 45
second warmup delay, the LED glows steadily green, the relay
circuit is no longer muted, and the preamplifier is ready for
F- Mono/Stereo Switch - When in the MONO position, this
switch combines the left and right signals to produce a mono
signal, which is useful for system troubleshooting when problems are suspected. When in the STEREO position, normal left
and right channel signals are processed.
G-Mute/Operate Switch - When in the MUTE position, this
toggle switch cuts off the signal to the SFL-1 Outputs (L), muting
the system (the LED (E) flashes as a reminder). When in the
OPERATE mode, the Outputs (L) are electrically connected,
allowing the signal to be passed to the next component (i.e.
a power amplifier or electronic crossover).
H-Volume Control - This knob allows variable control over the
SFL-1 output level. Turn it clockwise to increase the volume.
I- Power Switch - When in the ON position, this switch
allows the SFL-1 to receive power, rendering the SFL-1 operational, as indicated by the Power Indicator LED (E). When in
the OFF position, the SFL-1 is not receiving power and is not
Back view of the Signature version with Kimber jacks.
J- Detachable Power Cord Socket - Plug the Detachable
Power Cord into this socket (see Figure 1). The SFL-1 is factory
set for the correct operating voltage for the area in which it is
sold (see shipping box for voltage setting). If a different operating voltage is required, please contact an authorized Sonic
Frontiers dealer, distributor or the factory directly.
K-AC Line Fuse - This is the AC fuse socket. The fuse may be
accessed with a small flat-bladed screwdriver by turning the
fuse cap a 1/2 turn counterclockwise to unlock a spring that
ejects the fuse holder out. The unit is factory installed with
“fast-blo” .5 Amp 250V (0.25” x 1.25”) for 100-120V use
or .25 Amp 250V (0.25” x 1.25”) for 200-240V use.
L- Sets 1 & 2 of Left and Right RCA Single-Ended
Main Outputs - These outputs should be used when connecting to the single-ended RCA inputs on other units, such as
a power amplifier or crossover unit; connect left channel to left
channel and right channel to right channel. The two sets of outputs allow for easier biamping and greater flexibility over a single set of output jacks when dealing with components such as
electronic crossovers, powered subwoofers, etc.
M-Left and Right RCA Single-Ended Tape Output - This
output connects to the single-ended RCA input of a tape deck;
left channel to left channel and right channel to right channel.
These outputs are not operational when the Direct/Normal
Switch (B) is in the DIRECT mode, or when the Tape/Source
Switch (C) is in the TAPE mode.
N-Left and Right RCA Single-Ended Tape Input - This
input accepts a single-ended RCA input connection from a
tape source; left channel to left channel and right channel to
right channel.
O-Left and Right RCA Single-Ended Direct Input - This
input accepts a single-ended RCA input connection from a preferred line level source to achieve the highest possible sonic performance, bypassing unnecessary control functions; left channel to left
channel and right channel to right channel. This input is selected by
placing the Direct/Normal Switch (B) in the DIRECT position.
P- Left and Right RCA Single-Ended Auxiliary 2 Input
- This input accepts a single-ended RCA input connection from
any line level signal source; left channel to left channel and
right channel to right channel. It is selected via the Source
Selector Switch (A).
Q-Left and Right RCA Single-Ended Auxiliary 1 Input
- This input accepts a single-ended RCA input connection from
any line level signal source; left channel to left channel and
right channel to right channel. It is selected via the Source
Selector Switch (A).
R-Left and Right RCA Single-Ended Tuner Input - This
input accepts a single-ended RCA connection from a tuner
source; left channel to left channel and right channel to right
channel. It is selected via the Source Selector Switch (A).
S-Left and Right RCA Single-Ended CD Input - This
input accepts a single-ended RCA connection from a Compact
Disc Player or Digital-to-Analogue Converter; left channel to left
channel and right channel to right channel. It is selected via the
Source Selector Switch (A).
Figure 1 - Align socket pins to corresponding holes and push together firmly.
The SFL-1 comes with a 12AT7A (Ei) tube and the Signature
model with a CV4024/M8162 tube, individually boxed and
bagged along with a cotton glove, screwdriver, and screws for
fastening the SFL-1 cover. If desired, replacement of the tube
may be done to suit the listener’s preference. The following tube
types will work under the same technical parameters as the supplied tube and require no circuitry modification to function:
• 6201 • ECC81
Before plugging in the SFL-1, check to see that the unit is configured for the correct AC line voltage for country of use. The operating AC line voltage is indicated on the side of the shipping box. If
the SFL-1 Preamplifier is set incorrectly for the country in which it is
to be operated, contact the dealer or distributor in your area. If
the unit is configured properly, continue with operation.
Please read and follow these instructions carefully for initial
tube insertion or tube replacement.
DISCONNECTED from the SFL-1 before removing the chassis
2. Using the screwdriver supplied, remove the cover of the
SFL-1. For your convenience, only two of the screws are
installed at the factory.
3. When handling the tube, it is recommended that the cotton
gloves provided be worn to prevent skin oils from depositing
on the glass surface and possibly causing the tube to become
prematurely “gassy”, thereby shortening the tube’s useful operating life.
4. Take the tube and inspect the pins, noting the larger space
between two of the pins. This space will align with the same
larger space between two of the pin holes on the socket. Insert
the tube into the tube socket, making sure all pins and pin
holes are aligned (see Figure 2). Do not force the tube into the
socket. “Rock” the tube gently while pushing slowly until the
tube is firmly seated.
The SFL-1 Signature comes with a PearlTM Tube Cooler, for
extended life of the CV4024/M8162 tube. Install the cooler
at this point by placing the metal sinks around the glass envelope of the tube, keeping the bottom edge away from the the
top surface of the tube socket. Next install the 2 rubber “O”rings, spacing them evenly 1/3 from the bottom and 1/3
from the top to clamp the cooler firmly around the tube.
5. Replace the cover and fasten it with the screws provided.
The SFL-1 is now ready for operation.
Note the larger space
between two of the pins and
holes for proper alignment
of tube and socket.
Figure 2 - Tube pin alignment with the socket.
WARNING-DISCONNECT the AC Detachable Power Cord from
the SFL-1 and wait 5 minutes before removing the chassis cover.
Connect the Detachable Power Cord to the SFL-1 chassis (see
Figure 1) and plug your SFL-1 into the AC power source.
All remaining connections are made with co-axial cable and
RCA connectors to or from other single-ended units.
Connect source units to the Inputs of the SFL-1 (O through S);
left channel to left channel and right channel to right channel. It
is recommended that the preferred or most listened-to source be
connected to the Direct Input (O), to achieve the highest possible sonic performance (see Figure 3).
If a tape or other line level recording device is being implemented,
connect the left and right audio output of the unit to the corresponding left and right Tape Input (N) of the SFL-1. Also connect the left
and right Tape Outputs (M) on the SFL-1 to the corresponding left
and right audio inputs of the recording device (see Figure 3).
Connect Set 1 of the Main Outputs (L) on the SFL-1 to a stereo
amplifier or two mono amplifiers; left channel to left channel and
right channel to right channel (see Figure 3). Set 2 of the Main
Outputs (L) may be used under different situations and in combination with Set 1. These situations include biamping, the use of
active crossovers, powered subwoofers and other equipment, all
being unique and system dependent. Refer to the instruction
manuals provided with the other equipment before using the
second set of Outputs.
The SFL-1 Preamplifier is now ready for operation. Power the
Preamplifier by placing the Power Switch (I) in the ON position.
The Power Indicator LED (E) will flash on and off for approximately 45 seconds. During this time, the signal outputs are muted
while the tube is warming up and stabilizing. As soon as the
Power Indicator LED stops flashing the SFL-1 is ready to play.
Select a ready source through the Selector Switch (A) or by placing the Direct/Normal Switch (B) in the DIRECT position (if the
Direct Inputs (O) are connected to a ready source) to bypass the
Selector Switch, Balance Control (D), Tape/Source Switch (C)
and the Mono/Stereo Switch (F) for optimum performance.
Balance is adjusted through use of the Balance Control (D); turning it left and right will adjust the left and right levels respectively.
The centre “detent” is an indicator for equal or balanced left and
right levels.
Volume is adjusted through use of the Volume Control (H). Turning this control clockwise increases the volume level. Be sure the
level is sufficiently low when turning the unit ON, or returning to
the OPERATE mode after MUTING, to prevent damage to speakers, amplifiers or the SFL-1 itself.
To record from a source, place the Tape/Source Switch (C) in the
SOURCE position and commence recording. To play back a tape
recording, place the Tape Source Switch in the TAPE position.
Muting the SFL-1 Preamplifier is achieved by placing the
Mute/Operate Switch (G) in the MUTE position; the output signal is then cut off. To resume listening place the switch in the
OPERATE position.
The mono/stereo function is controlled by Mono/Stereo Switch
(F). When this switch is placed in the MONO position the left
and right stereo signal is combined and the SFL-1 will send an
identical mono signal to the left and right Main Outputs (L). In the
STEREO position, normal stereo playback is produced.
check that:
• A “fast-blo” fuse, with a rating of .5 Amp/250 V (.25 Amp/250 V
for European and Asian versions), is installed in the cylindrical tube
next to the AC power socket.
• The AC power fuse is intact and has not blown. If the fuse has
blown the thin metal conductor will have melted and the glass may
appear “smoked”. If the fuse has blown, replace with a fuse of the
same rating (.5 Amp/250V fast-blo for 100 to 120 volt countries and
.25 Amp/250V fast-blo for 200 to 240 volt countries).
NOTE: Under no circumstances should you replace the AC power
fuse with one of a higher current rating! Doing so may cause further
damage to the SFL-1 and will also void the warranty. In addition, your
continued protection from risk of fire or shock would be seriously compromised.
If at any time the SFL-1 Preamplifier fails to work properly, consult this
4. DISCONNECT THE AC POWER CORD, wait 5 minutes, remove
the chassis cover and ensure the tube is plugged firmly into its socket
as described in “INSERTION OF THE TUBE”.
1. Check that the AC Detachable Power Cord is plugged into the
SFL-1 Detachable Power Cord Socket (J) and is connected to a live
source of AC power. For instance, if using a power bar, check that
the bar is turned on.
5. Be sure the rest of the system is functioning properly (i.e. source unit,
power amplifiers, cables and connections, etc.).
2. Ensure that all Input and Output connections are secure for
a proper electrical contact.
6. Check that both the front panel Power Indicator LED (E) is lighted
(glowing light green). If all of the above troubleshooting steps have
been followed and the LED is not lighted (remains dark green), contact
your dealer or distributor for assistance.
Figure 3 - Single-Ended RCA Input and Output connections made to the SFL-1 Preamplifier.
Allow at least 4” (15 cm) of clear space above the SFL-1 chassis for proper ventilation, making sure the air vent slots in the
chassis cover remain unobstructed. Also, be sure that the SFL-1
Preamplifier is placed on a secure, hard, and level surface.
Sonic Frontiers, Inc. warrants to the purchaser that each SFL-1
Preamplifier is free of manufacturing defects for a period of five
(5) years from the date of purchase. This five (5) year limited
non-transferable warranty excludes all vacuum tubes, which we
warrant for a period of twelve (12) months. To receive this warranty, the original purchaser must complete and mail to Sonic
Frontiers, within thirty (30) days from the date of purchase, the
enclosed Warranty Registration Card. Sonic Frontiers, Inc. will
then validate the warranty to the original purchaser. This warranty is subject to the following conditions and limitations:
1. Ventilation - Although your SFL-1 Preamplifier generates only
nominal heat in use, be sure that the ventilation slots in the top
cover have at least 4” of unobstructed air space above them.
2. Water and Moisture - This product should not be used near
water. To prevent fire or shock hazard, do not expose this
product to rain or moisture.
3. Heat - This product should be situated away from heat
sources such as radiators, heat registers, stoves, or other appliances which produce heat.
4. Power Sources - This product should be connected to an AC
power source of the proper rated voltage. The original shipping containers will stipulate the AC voltage this unit can operate with correctly.
5. Cleaning - A regular dusting with a soft, non-abrasive cloth
will generally keep the finish of the faceplate and chassis looking like new. At no time should you allow any liquid to come in
contact with the SFL-1 Preamplifier; it may run into the electronic circuitry and cause damage which will not be covered under
your warranty.
6. Servicing - Do not open this product. No user serviceable
parts inside. Refer servicing to an authorized service technician.
7. Non-Use Periods - The power cord of this product should be
unplugged from the outlet when left unused for an extended
period of time.
8. Do not remove the SFL-1 chassis cover while the unit is “on”,
or connected to an AC power source. Cover screws could fall
through the ventilation slots and cause electrical damage to the
We recommend that you retain all of the packing material and
shipping boxes for your SFL-1 Preamplifier. They are custom
designed to prevent shipping damage from occurring. Sonic
Frontiers, Inc. will accept no responsibility for any damage
occurring to an SFL-1 Preamplifier that is shipped in packing
material other than the original Sonic Frontiers packing material.
1. Warranty applies only to the original purchaser.
2. This warranty is void and inapplicable if the product has
been handled other than in accordance with the instructions in
this Owner’s Manual, abused or misused, damaged by accident or neglect or in being transported, or the defect is due to
the product being tampered with, modified or repaired by anyone other than Sonic Frontiers, Inc. or an authorized Sonic
Frontiers repair depot.
3. Warranty does not cover normal maintenance.
4. Sonic Frontiers, Inc. shall not be responsible in any way for
consequential or indirect damages or liabilities resulting from
the use and operation of the product covered herein or resulting from any breach of this warranty or any implied warranty
relating to said product.
During this period, Sonic Frontiers, Inc. will repair or replace
any defective components free of charge. A Return Authorization Number (RA Number) is required before any product is
returned to our factory for any reason. This number must be visible on the exterior of the shipping container(s) for Sonic
Frontiers to accept the return.
Units shipped to us without a Return Authorization Number or
without a visible RA Number on the exterior of the shipping
container(s) will be returned to the sender, freight collect.
Units to be repaired by Sonic Frontiers, Inc. must be sent shipping and insurance prepaid by the original purchaser in the
original packing material. A returned product should be accompanied by a written description of the defect. Repaired units
will be returned by Sonic Frontiers, Inc. shipping and insurance
Under no circumstances does Sonic Frontiers, Inc. assume liability or responsibility for injury or damages sustained in the use
or operation of this equipment or for damages to any other
equipment connected to it.
Sonic Frontiers, Inc. reserves the right to make design changes
or improvements without the obligation to revise prior versions.
All specifications are subject to change without notice.
All other warranties or conditions either written or implied
are void.
Note: In foreign markets (anywhere outside of Canada and the
USA), the warranty is supplied by the authorized International
Distributor. Exact terms and conditions may vary.
Frequency Response
(100K load)
2 Hz to 100 kHz ±0.5 dB
> 200 kHz -0.3 dB
(@ 1 V output)
< 0.1% from 20 Hz to 20 kHz
typically < 0.05% @ 1 kHz
20 dB @ 1 kHz
180 uV unweighted
(volume control @ 12 o’clock)
-85 dB below @ 2 Volt R.M.S. output
< 0.3%, @ 2 V output
Input Impedance
45 K ohms (Direct input)
90 K ohms (Normal inputs)
Output Impedance
320 ohms @ 1 kHz
Minimum Recommended Load Impedance 10 K ohms
Output Voltage
Maximum 25 V R.M.S.
Maximum Input
2.5 V R.M.S. (Volume control fully clock-
Stereo Separation
60 dB @ 1 kHz (Crosstalk)
Power Requirements
20 VA 160 mA A.C./120V A.C.
20 VA 80 mA A.C./240V A.C.
Fuse Requirements (2)
0.5 Amp 250 V fast-blo
(100 V to 120 V Countries)
0.25 Amp 250 V fast-blo
(200 V to 240 V Countries)
Tube Complement
1 - 12AT7A (Ei)
1 - CV4024/M8162 (Signature Version)
19” Wide x 11.5” Deep x 4.5” High
(48 cm x 29.25 cm x 11.5 cm)
22 lbs (10 kg) - unpacked
5 years parts and labour
1 year on the tubes
This symbol 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 electric shock to persons.
This symbol is intended to alert the
user to the presence of important
operating and maintenance (servicing)
instructions in the literature accompanying the appliance.
We at Sonic Frontiers are sure that you will derive many years
of listening pleasure with your new SFL-1 Preamplifier. This
Owner’s Manual contains important information regarding the
operation and care of the SFL-1. Be sure to read this manual
carefully and follow these instructions in order to keep it looking,
operating and sounding its best.
2790 Brighton Road, Oakville, Ontario, Canada L6H 5T4
Telephone: (905) 829-3838 Facsimile: (905) 829-3033
Sonic Frontiers can be reached from 9:00 a.m. to 6:00 p.m., Eastern Standard Time (E.S.T.), or 24 hours a day by facsimile.