Musical Surroundings Fosgate Signature User manual

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Owner’s Manual

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Table of Contents
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Read This First…………………………………….2
Introduction by Jim Fosgate……………………...3
Unpacking…………………………………………..4
Tubes and Tube shield Installation………………5
Product Placement………………………………...6
Connecting your Fosgate Signature……………..7
Phono stage settings…………………………7 & 8
Powering UP……………………………………….8
Tube Rolling………………………………………..9
Specifications……………………………………..10
Warranty and Service……………………………11

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Read This First
Please read carefully the following safety instructions,
which have been included in compliance with
international safety regulations.
•Read this instruction manual prior to connecting and
operating this unit. Retain this manual for future reference.
•Retain all packing materials and carton for future need.
•To prevent fire or shock hazard, do not expose this unit to
rain or moisture or operate in these conditions.
•This unit contains voltages that can cause serious injury or
death. Do not remove the bottom cover at any time.
•To avoid risk of burns, do not touch vacuum tubes when the
unit is powered on or within 30 minutes of powering down.
•No user serviceable parts are inside. Service should only be
performed by Musical Surroundings or our authorized repair
agents.
•In case of fuse replacement (located in IEC receptacle),
disconnect AC cord prior to replacement and replace ONLY
with fuse of identical type and rating.
•Never place any object or material over this unit, restricting
ventilation, to avoid risk of fire.

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Introduction
•The design is the result of more then 100 different hand built preamp
circuits dating back to the 1970s.
•All amplification is accomplished with the SRPP (push pull) configuration
for the best possible linearity, lowest noise and distortion.
•No solid-state devices are placed in the signal path and a tube is used for
the high voltage rectifier.
•The power supply is very different and contributes to the high
performance. There are no regulated power supplies. Each tube stage is
powered by a separate storage capacitor that acts like a battery. These
storage capacitors are very large (10 to 20 time’s oversize). The power
supply simply holds the voltage across the capacitors like a “trickle
charger”. PC board layout is “Dual Mono”. The channels are located on
opposite sides of the circuit board in near mirror image with dual triodes in
a row down the center.
•The first stage has no NFB to interact with the cartridge. The second and
third stages are enclosed in a single feedback loop incorporating both
positive and negative feedback.
•The RIAA network is divided into two sections, one passive and one
active. The upper half (above 1KZ) is accomplished with a passive
network between stage one and two. The lower half (below 1KZ) is
accomplished with an active network around stage two and three.

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Unpacking
Opening the cartons:!!Use caution when opening the cartons
with a sharp edged tool not to damage any of the contents.
Included with your Fosgate Signature phono stage is a pair of white
gloves for handling both the unit as well as the tubes. This will avoid
any finger oil from getting on the tubes that could cause irregular
heating of the glass.
Foam packing:!!When you open the inner carton, you will see a
layer of foam covering the phono stage. There are cut outs in the
foam containing each vacuum tube, located in the appropriate
position. Be careful when lifting the foam so that the tubes do not fall
out. Alternately, you can remove the tubes from the foam before
removing the foam itself. Please note the location and marking for
each tube. Refer to the next page for specifics on tube installation.

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Tube and tube shield installation
Tube compliment:
2 6DJ8’s - V1 and V2
2 12AX7 - V3 and V4
2 12AT7 - V5 and V6
1 6X4 - high voltage rectifier
Install the tubes:!!When inserting tubes into their sockets, be
very careful not to bend the metal pins. Begin by installing the tall
6X4 rectifier tube into the socket just in front of the power transformer
housing. Continue installing the other six tubes by first inserting two
6DJ8’s in the two sockets nearest the rear of the chassis, V1 and V2.
Next, insert two 12AX7’s in the middle two sockets, V3 and V4. And
finally, install two 12AT7’s in the remaining sockets nearest the front
panel, V5 and V6.
Install the tube shields: The three silver tube shields
provided are vitally important in keeping noise away from the three
most rear tubes, V1, V2 and V3. There is a gap around those three
tube sockets, and down in each of those gaps are two metal pins that
the tube shields lock on to. Note the locking-slots at the bottom of the
tube shields. The unit should be powered off with AC cable
disconnected.
1
MM
MC
LEFT
MM
MC
RIGHT
POWER TRANSFORMER
6X4
FRONT OF UNIT
6922
6922
12AX7
12AX7
12AT7
12AT7
2
3
4
5
6

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Align those slots over the pins and carefully insert the tube shields
over the three tubes. There are springs inside the top of the shields
therefore you will need to push down until you feel the shields hit
bottom, then twist them in a clockwise direction to lock the shields
onto the pins. Adjust the tubes and shields to stand up straight.
Placement of the preamp:
The Fosgate Signature phono stage should be placed close to the
turntable in order to use as short as possible phono cables between
the tonearm and the unit. Position the phono stage away from hum
producing sources such as motors, transformers and power cords.
Good ventilation is essential for safety and the life of the phono stage.
Allow at least 2” of clearance above the unit, and avoid placement on
a shelf directly above a heat and noise source such as a power
amplifier. Ideally, the shelf should be constructed of non-resonant
material to minimize microphonics.

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Audio Connections: Before connecting to your line-stage
preamp or integrated amp, make sure the volume control of that unit
is completely turned
down. Connect your
turntable to the left and
right “INPUTS” of the
phono stage, then
secure the turntable
ground wire to the
grounding post
provided on the back
panel. Next, connect a
pair of cables to the left
and right “OUTPUTS” of the phono stage. The other ends of these
cables connect to line level inputs or “AUX” type inputs of a line-stage
preamp or integrated amp. *Do NOT connect these cables to inputs
marked “PHONO” as these typically have circuitry redundant and
inferior to your Fosgate Signature phono stage! (Please consult your
owner’s manual of line stage or integrated to verify as some units
may label a standard line level input as “phono” for convenience).
The output impedance of your Fosgate Signature is low enough to
drive solid state preamps down to a 10K input impedance. This is
accomplished without a cathode follower or solid-state buffer in the
output to affect the sound.
Power Cord Connections: Your Fosgate Signature phono
stage is fitted with a male IEC AC input
connector and supplied with a high gauge
IEC grounded power cord. With the phono
stage power switch in the off (down) position,
attach the female end of the power cord to
the unit and the 3 prong AC plug to a
suitable AC outlet. Due to the high
performance of thus unit, you may prefer an
after-market high quality AC cord. Consult
your Musical Surroundings dealer in this
regard. You may also need to use an AC “cheater plug” or ground
lifter if you encounter a ground loop in your system.

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Settings: Refer to the information sheet for your phono cartridge
to determine the output voltage specification and the recommended
cartridge resistive loading setting or range. A pair of gain switches
are located at the base of the third tube from the back of the chassis
(see picture page 6, right channel visible). Left and right channel gain
switches provide a gain of 60dB (MC) or 42dB (MM). If you are using
a Low Output Moving Coil cartridge with less than 1 millivolt output,
position both switches forward (toward the face panel as in the photo
on page 6). When using a High Output Moving Coil cartridge with
more than 1 millivolt output, or, if you are using a Moving Magnet
cartridge, place both switches in the rearward position.
Cartridge loading: Using the rotary
knob on the back of the phono stage, select
the recommended resistive load based on
your cartridge specification sheet. The
cartridge load knob provides loading from 50
ohms to 100k ohms. Typically, MC cartridge
loading is a minimum of 10 times the internal
impedance of the MC cartridge. High output
MC cartridges and MM cartridges typically
load at 47k ohms. The 100K position is used
with MM cartridges when more high
frequency response is desired providing a
closer balance to a MC cartridge. Input
capacitance is very low. You may change
loading to listen to the sound difference but turn down your line stage or
integrated amp volume control completely down prior to changing the
loading setting.
Powering up: Make sure all connections are in place and your
line stage or integrated amp volume control is completely turned
down prior to
powering up your
phono stage. The
blue lights come
on 30 seconds
after power up,
indicating voltages
have stabilized
and listening can begin. The sound may improve after several
minutes of warm up.

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Tube Rolling: Your Fosgate Signature phono stage ships with an
extra 12AT7 tube that can be used in place of the 12AX7 in position V3 to
give a slightly more detailed top end. Final choice will depend on listener
preference and audio system.
Do not change tubes when the unit is powered on. To avoid risk of
burns, do not touch vacuum tubes when the unit is powered on or
within 30 minutes of powering down.
Below is a list of equivalent tubes used in your Fosgate Signature
phono stage if you wish to tube roll. Please check with your Musical
Surroundings’ dealer regarding availability of tubes for this purpose.
Please note that tubes obtained from an independent source that
causes damage to your Fosgate Signature phono stage is not
covered under the warranty.
V1 and V2 - 6DJ8/ ECC88
Equivalent: 6922/ E88CC, 7308
V3 and V4 - 12AX7/ ECC83
Equivalent: 7025, 5751
V5 and V6 - 12AT7/ ECC81
Equivalent: 6201
V7 - 6X4 - high voltage rectifier

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SPECIFICATIONS
Gain: 42dB MM, 60dB MC
Loading: 100Ω, 300Ω, 500Ω, 1kΩ, 47kΩ, 100kΩ
Capacitance: 50pf
Tube compliment:
2 6DJ8’s V1 and V2
2 12AX7 V3 and V4
2 12AT7 V5 and V6
1 6X4
Dimensions: 13 3/16" W x 10 3/4" D x 5 5/8" H
Weight: 10 lbs
5662 Shattuck Ave
Oakland, CA 94609
510 547-5006
fax [phone]
[email protected]
www.musicalsurroundings.com

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90 DAY LIMITED WARRANTY TERMS AND CONDITIONS
(2 Year optional extended service contract)
1. Musical Surroundings warrants the product designated herein to be free of manufacturing
defects in material and workmanship, subject to the conditions herein set forth, for a period of 90
days from the date of purchase by the original purchaser. If the purchaser registers the unit with
Musical Surroundings by mailing in the warranty card, together with a copy of the bill of sale,
within 14 days of the date of purchase, said purchaser will be registered for an extended service
contract. The extended service contract extends the 90 days to a period of 2 years from the date
of purchase by the original purchaser or no later than 3 years from the date of shipment to the
authorized Musical Surroundings dealer, whichever comes first. Tubes carry a 90 day warranty
only.
2. CONDITIONS - This warranty is subject to the following conditions and limitations. The
warranty is void and inapplicable if the product has been used or handled other than in
accordance with the instructions in the owner's manual, abused or misused, damaged by
accident or neglect or in being transported, or the defect is due to the product being repaired or
tampered with or modified by anyone other than Musical Surroundings or their authorized repair
stations. To obtain warranty service, you must first contact Musical Surroundings at 510 547-5006
or [email protected] to obtain a Return Authorization (RA) number. The
product must be packed in its original carton and returned to Musical Surroundings or authorized
repair station by the customer at his or her sole expense. A returned product must be
accompanied by a written description of the defect and a photocopy of the original purchase
receipt. This receipt must clearly list model and serial number, the date of purchase, the name
and address of the purchaser and authorized dealer and the purchase price. Musical
Surroundings reserves the right to modify the design of any product without obligation to
purchasers of previously manufactured products and to change the prices or specifications of any
product without notice or obligation to any person.
3. REMEDY - In the event the above product fails to meet the warranty, and the above conditions
have been met, the purchaser's sole remedy under the limited warranty shall be to return the
product to Musical Surroundings where the defect will be rectified without charge for parts or
labor.
4. LIMITED TO ORIGINAL PURCHASER - This warranty is for the sole benefit of the original
purchaser of the covered product and is NOT TRANSFERRABLE.
5. DURATION OF WARRANTY - This warranty expires 90 days after the date of original
purchase. If Musical Surroundings receives the warranty registration card, this period is extended
to the second anniversary of the date of purchase or no later that the third anniversary of the
shipment to the authorized Musical Surroundings dealer, whichever comes first.
6. MISCELLANEOUS - ANY IMPLIED WARRANTIES RELATING TO THE ABOVE PRODUCT
SHALL BE LIMITED TO THE DURATION OF THIS WARRANTY. THE WARRANTY DOES NOT
EXTEND TO ANY INCIDENTAL OR CONSEQUENTIAL COSTS OR DAMAGES TO THE
PURCHASER. Some states do not allow limitations on how long an implied warranty lasts or an
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.
7. WARRANTY OUTSIDE THE USA - Musical Surroundings has formal distribution in many of
the countries of the free world, in each country the Musical Surroundings importer has
contractually accepted the responsibility for product warranty. Warranty should normally be
obtained from the importing dealer or distributor from whom you obtain your product.