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SLP 05
Pure Balanced Vacuum Tube Preamplifier
Owner’s Manual
NOTE: Before installing your new component, please read this manual carefully as it will inform you of the
specifications, proper installation and operation procedures. Also included in this manual are guidelines on how to
service and care for your new Cary Audio Design product.
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CONTENTS _________________________________________________________
Welcome................................................................................................................................3
Introduction......................................................................................................................4-5
Specifications ...................................................................................................................6-7
Features........................................................................................................................... 7-12
Installation ..........................................................................................................................12
Operation ............................................................................................................................13
Service and Care ...............................................................................................................14
Warranty.......................................................................................................................15-16
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WELCOME__________________________________________________________
Dear Music Lover,
I would like to personally thank you for your decision to invest in the new
Cary Audio Design SLP 05 preamplifier. The SLP 05 is a continuance and
elevation of the SLP series of preamplifiers originating in 1990. The SLP
series has been in continuous production for over 15 years and provides
musical enjoyment across the world.
In sound quality alone, the SLP 05 transcends all previous Cary Audio
Design preamplifiers and elevates both digital and analog sources to their
full musical potential. The SLP 05 is a fully balanced, full-featured
preamplifier that includes a vacuum tube headphone stage along with
vacuum tube power supply. The SLP 05 is the preamp of choice for
exceptional sound that rivals live performance.
Thank you for your support and interest in Cary Audio Design.
Dennis J. Had
President
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INTRODUCTION____________________________________________________
Congratulations!
You have just purchased one of the best preamplifiers made. The following is an overview of the design
characteristics of the SLP 05.
The SLP 05 employs a fully balanced circuit topology, from input-to-output, that actively cancels external
electrical and radio frequency noise picked up by audio cables. The sonic result is a greatly improved
signal-to-noise level ratio with palpable, three-dimensional images of instruments and vocalists in a
natural acoustic space. Balanced operation also ensures more than adequate output voltage to drive any
balanced amplifier throughout the entire audio range with the all-too-rare combination of vibrancy,
immediacy and control. An added feature of the new SLP 05 permits “balanced to single-ended” and
“single-ended to balanced” audio connections for the greatest flexibility of use in your system.
Listeners today have more choices of playback sources than ever before, and the SLP 05 offers complete
flexibility to accommodate them. In addition to three RCA unbalanced line level inputs, there are two
balanced XLR stereo inputs along with a dedicated tape input as well. Included is a pair of cinema
processor inputs for either RCA single-ended or XLR balanced connections. Outputs include both RCA
single-ended and Balanced XLR connections. The XLR balanced in and out connections follow the “Cannon
plugs” pin out wiring standard. Pin #1 is the shield, pin #2 is the normal-phase (hot lead) and pin #3 is the
inverted signal.
The special Cinema Bypass feature routes the balanced or unbalanced cinema inputs directly to their
corresponding outputs, bypassing all the SLP 05 circuitry and turning over control to the user’s cinema
processor. The cinema bypass circuitry may be engaged by toggling the Cinema bypass switch on the
front panel of the preamplifier. If the SLP 05 power switch is turned to the off position, the SLP 05
automatically defaults to the cinema bypass mode.
All switches in the SLP 05 are gold-contact types to ensure signal purity and high resistance to wear and
oxidation over years of use. Single-throw toggle switches and solid-seating rotary switches along the
machined aluminum front panel are easy to use and provide unambiguous indication even in low light.
All source inputs and the audio mute function are switched through hermetically sealed, gold plated
contact relays. Listening level (volume) is controlled with a high-precision Alps potentiometer that is
mechanically driven by command from the infrared remote control. A front-panel mute/operate switch
offers additional convenience when switching cables or changing a record. Remote muting is also possible
by switching the SLP 05 remote handset button to the mute position. The remote handset now takes over
the control of this feature.
Reflecting the growing popularity of high performance headphones, the SLP 05 features a state of the art
headphone amplifier stage based on the popular 6SN7 vacuum tube. This is a “zero feedback” circuit
design and is transformer-coupled, guaranteeing extended, uniform frequency response regardless of the
headphone driver type. Sufficient drive current is available to power headphones with impedance’s from
30 to 300 ohms. A front panel toggle switch allows use of the onboard headphone amplifier.
Circuitry
The SLP 05 is a no compromise line stage and headphone amp. The power supply is vacuum tube rectified
and has a 5AR4 vacuum tube rectifier lying on its side inside the unit. The 5AR4 tube has a separate
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cathode from the filament so any position of mounting is proper. It was horizontally mounted to keep the
power supply the same height as the preamplifier. The rectifier tube provides the high-voltage (B+) plate
voltage. Two separate filter chokes and a fully regulated shunt coupling capacitor ensure stable and
ripple-free voltage resulting in a very low noise and spacious sound stage.
The preamplifier has eight (8) 6SN7 dual triodes octal socket vacuum tubes. Four (4) of the 6SN7's act as
the true balanced main line section. Two (2) of the 6SN7's are operating in the front end ahead of the gain
stage as balanced plus/minus 180 degree input buffer stage. The remaining two (2) 6SN7's function as a
‘Class A’ push-pull zero feedback headphone amplifier. This headphone section amplifier has two on
board output transformers to transform the high impedance of the 6SN7's to low impedance for driving
the headphones.
There are two power switches to control the AC input voltage to the preamplifier. The large knob on the
power supply is the mains power switch. If one places the power supply in another location, the main
power switch is turned on. A blue LED in the knob indicates the power supply can be activated by the
preamplifier section. Turning the preamplifier power switch sends 12 volts DC to the power supply relay to
turn on the main power transformer that powers the tube rectification along with all other voltages
required to place the SLP 05 in operation. The two meters on the front of the power supply indicate the
B+ plate voltage (210 VDC) along with the plate current (60 ma.). You will always know at a glance if all is
OK with the operating conditions.
The SLP 05 is engineered and built to provide a lifetime of musical enjoyment with facilities and features
that ensure future compatibility and audiophile performance for many years to come. This preamplifier is
a future collector’s item and deserves to be installed with the finest ancillary equipment available, such as
the CD 306 SACD player or the CAD 211 Anniversary Edition power amplifiers.
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SPECIFICATIONS ___________________________________________________
This section describes the basic specifications of the SLP 05 vacuum tube preamplifier at the time of
printing. Specifications are subject to change without notice or obligation. When the following cautionary
terms are used in this manual, these definitions apply:
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 of personal injury or equipment damage; however, misuse or failure to follow
instructions may prevent proper performance of the equipment.
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CIRCUIT DESIGN Class A Triode Vacuum Tube Preamplifier Design
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OUTPUT VOLTAGE 2 Volts rated, 12 Volts maximum
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OVERALL GAIN 10 dB Single-ended RCA
8 db Balanced Operation
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RATED DISTORTION 0.03 % THD
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NOISE AND HUM -90 dB below full output
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INPUT IMPEDANCE 50,000 Ohms - RCA
100,000 Ohms - XLR
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OUTPUT IMPEDANCE 400 Ohms
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FREQUENCY RESPONSE 5 Hz to 250,000 Hz
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VACUUM TUBES 8 ea - 6SN7 octal tubes for the balanced, headphone and gain stages
1 ea – 5AR4 Rectifier Tube in Power Supply
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POWER TRANSFORMER(S) R CORE 200% Duty Cycle
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RESISTORS 1% Metal Film
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CAPACITORS Polystyrene, Film and Foil
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POWER SUPPLY CAPACITORS 2 ea - 560µF @ 400 VDC
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