Conrad-johnson design PREMIER 17LS User manual

Thank you for selecting the Conrad-Johnson Premier 17LS line stage
preamplifier as the control center for your audio system. The Premier
17LS is our most affordable implementation of the engineering ad-
vances pioneered in our flagship Anniversary Reference Triode pream-
plifier. The Premier 17LS is capable of remarkably faithful recreation of
thedynamics,textures,tonalities,andambienceoflivemusicalperform-
ances. Using it, we believe that you will experience the excitement of
discovery in hearing more from your favorite recordings than ever
before.
Atconrad-johnson, weexpect ourproducts tobe asource ofsatisfaction
and of pride to their owners for many years to come. Accordingly, circuit
designs, parts and materials for all conrad-johnson products are se-
lected with a view to maintaining optimal performance over the years.
Our reputation for producing among the industry’s most reliable compo-
nents is a natural consequence of this engineering approach.
Although the Premier 17LS has been designed to operate in an intui-
tively apparent way, you will find useful information on it’s installation
and operation in this manual. Please take a few minutes to read the
manual to better understand the features and capabilities of your Pre-
mier17LS.Notethatthisunitisphaseinverting.See the section entitled
"Getting The Most From Your Premier 17LS" for details on correct
hookup in your system.
In closing, we’d like to welcome you to the family of conrad-johnson
owners. We want you to enjoy your conrad-johnson product to the
fullest. To this end, our staff stands ready to answer any questions you
may have about the function and application of your Premier 17LS, and
to provide any needed service both during, and after the warranty
period. Our goal is to heighten your enjoyment of recorded music.
Premier 17LS Owner’s Manual 1

Limited Warranty For Conrad-Johnson Components
conrad-johnson design, inc. will provide service under warranty to the
original owner on products sold new in the United States for the lesser
period of three years from the date of purchase by the original pur-
chaser, or five years from the date of shipment to the authorized
conrad-johnson dealer. During the warranty period, conrad-johnson will
repair defective units without charge for labor or parts (with the excep-
tion of vacuum tubes and batteries).
Exclusions. The following are not covered under this warranty:
a) Units which have been damaged by misuse, abuse, or accident.
b) Units which have been modified, altered, or improperly repaired by
anyone not specifically authorized by conrad-johnson design, inc.
c) Units not purchased from an authorized conrad-johnson dealer in the
United States for use in the United States.
d) Normal wear
e) Incidental or consequential damages are not covered under this
warranty. Some states do not allow the exclusion of incidental or
consequential damages, so this exclusion may not apply to you.
Obtaining Warranty Service:To obtain warranty service, the unit must
be shipped, along with evidence of purchase, in factory packing to
conrad-johnson design (or designated service center) with freight and
insurance prepaid by the owner. After repair, the unit will be returned
with freight and insurance prepaid by conrad-johnson design to any
destination in the United States.
All implied warranties, including merchantability and fitness for a par-
ticular purpose are limited in duration to the duration of this express
warranty. Some states do not allow limitations on the duration of implied
warranties so the above limitations 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.
Premier 17LS Owner’s Manual 2

Conrad-Johnson products purchased outside the United States are
covered by warranty terms of the importing distributor in the country in
which the product was originally purchased, which may differ from the
terms set out herein. Importing distributors are not obligated to provide
warranty service for products originally purchased outside their country.
Conrad-Johnson will provide warranty service for products outside the
United States, but in these cases, the customer must pay all shipping,
handling and customs costs both to and from our Service Department.
Questions about this warranty should be addressed to:
Service Department
conrad-johnson design, inc.
2733 Merrilee Drive
Fairfax, VA 22031
The conrad-johnson service department can also be reached by email
at [email protected], by phone at 703-698-8581, or by fax
at 703-560-5360.
Service
If your conrad-johnson audio component requires service, repack it
using the original box and packing material and ship to the Service
Department address above. Boxes and packing materials can be ob-
tained from our service department for a nominal charge, if you no
longer have yours. Include with the unit a note describing the problem
you are having in as much detail as possible. It is especially important
for our technician to know if the problem is intermittent. If you want an
estimate of cost for out of warranty service, be sure to request it in this
note.Be awarethat requestinganestimatewilldelayservicetoyourunit
as we will have to contact you for your approval before commencing
service.
Registering The Warranty
Please return the enclosed card to the factory within 30 days of pur-
chase to register the warranty
Premier 17LS Owner’s Manual 3

Installation
The first step in preparing your Premier 17LS preamplifier for use is to
install the vacuum-tubes. To do this, remove the top plate of the tube
guardbyremoving thefourscrews securingitto the guard.The Premier
17LS uses four type 6922 tubes. After checking the pin orientation,
insert one tube in each tube socket. Next, fit two of the included silicone
rubber rings over each tube, spaced at roughly 1/3 and 2/3 distances.
These rings will minimize the effects of air-borne microphonics on the
tubes. Finally, reinstall the top plate of the tube guard.
Set Up
To maintain proper ventilation, mount the Premier 17LS horizontally on
aflat,hard surface, andtakecare that theventilationholes in thebottom
are unobstructed. Allow at least two inches of clearance above the unit
andkeep thecabinetorshelfopen attheback.Verticalinstallationisnot
recommended.
All Premier 17LS sold in the United States are configured for operation
on a 60Hz ac power line producing between 108 and 126 volts. Export
versionsofthe Premier 17LSwillhave the correctoperatingvoltage and
frequency clearly marked on the back panel of the unit, near the ac
power cord. In all cases, the actual line voltage should be within + 5/-
10% of the nominal rated voltage.
Premier 17LS Owner’s Manual 4

Electromagnetic Interference (EMI)
Considerable care has been taken in the design of the Premier 17LS to
minimize it’s susceptibility to radio frequency interference and other
forms of EMI. Choice of materials, physical layout, grounding practice,
andpowersupply designhaveall beenspecifiedwith a viewto reducing
the impact of electromagnetic fields on the performance of this unit. At
the same time, however, our primary goal is the accurate reproduction
of recorded music in the normal home environment, and we have
elected not to compromise this objective by the application of heavy-
handed RFI filters, or by using grounding practices that reduce RFI at
theexpenseof degradedaudioperformance. Wefindthat the approach
we have taken has worked extremely well, resulting in only rare in-
stances of EMI problems which could be treated locally as needed,
rather than compromising the performance of our product in the 99.9%
of installations where EMI is not a problem.
CareininstallationcanoftenavoidEMIinducedproblems.Thefollowing
practices should generally be observed in any application, and will be
especially important where EMI may be a problem.
Interconnect cables should be kept as short as possible (3 meters or
less), and shielded cable should be used (cable which has two center
conductors, and a separate external shield connected at only one end).
Physical location and cable "dress" can be an important factor in
minimizing hum pickup. The installation should situate the preamplifier
well away from the power amplifier, and power (ac mains) cords should
be dressed to remain at least 4" (100mm) away from input/output
cables.
Premier 17LS Owner’s Manual 5

Connection
SOURCES (PH/AUX1, TUNER, CD, VIDEO, AUX2): These high level
inputs are electrically equivalent. The load they present to the source
varies with the volume control setting, but in no case will it drop below
12 kohms. Connect the corresponding source components to these
inputs.
EXTERNAL PROCESSOR LOOP (EPL1): A set of line-level inputs and
outputs provided for connection of external signal processors (e.g.
parametric equalizer, tone controls). These can also be used for the
connection of a tape recorder. In this case, connect the EPL OUT to the
recording input of your tape recorder, and the EPL IN to the output of
your tape recorder. The EPL IN connection can also be used as an
additional line level input.
THTR/EPL2: This is an external processor loop designed to conven-
iently accommodate the addition of a surround-sound processor (SSP)
to a high-quality two channel system without compromising two channel
performance. Connect the front left and front right channel outputs from
your SSP to the THTR/EPL2 input. You can also connect the
THTR2/EPL2 OUT to an input on your SSP, allowing you to do matrix
processing on selected two channel sources. When this THTR loop is
selected, the level controls are set to unity gain. Level and balance
control is then accomplished via your surround sound processor.
MAIN OUT1 and MAIN OUT2: Connect to the input of your amplifier (or
crossover in a bi-amplified system). We recommend the use of an
amplifier with an input impedance of 20k ohms or higher. Since the
Premier 17LS inverts phase, it may be necessary to invert the speaker
leads to maintain correct absolute phase. See the section on "Getting
the most out of your Premier 17LS" for an explanation.
Premier 17LS Owner’s Manual 6

Controls
power: Press the button labeled power to switch the preamplifier on. A
time delay auto-muting circuit is incorporated into the Premier 17LS to
eliminate transients generated by the warm-up, and cool down cycles of
thevacuum-tubes. Alloutputs aregroundedviarelaysforapproximately
90 seconds after the unit is turned on in order to suppress warm-up
transient noises. During this auto-muting period, the mute indicator led
(located next to the mute button) will flash. All control functions are
disabled during the auto-muting cycle. The muting relay also grounds
the outputs immediately at turn-off or in the event of any power line
interruption. When the Premier 17LS is turned off (by pressing the
power switch again), the standby led (located in the display window) will
be illuminated.
When first connected to ac mains, or after an interruption of power, the
Premier 17LS will turn on in a default mode (after auto-muting), with the
level set at 20, and the CD input selected. In subsequent sessions, as
long as the ac mains has not suffered a power outage, the unit will turn
on at the last used volume setting and input.
source (phono/aux1, tuner, cd, video, aux2): Pressing the button
labeled source will cause the unit to step through these five inputs, in
the order displayed on the front panel. The selected input will be
indicated by an illuminated led.
epl (source, epl1, epl2/theater): Pressing the epl button will cause the
unittostep from sourcethroughthe two externalprocessorloops. When
source is selected, the input selected as source will be passed directly
to the volume control. When EPL1 or EPL2/THEATER are selected, the
selected source will first pass through the external processor loop
before being routed to the volume control. When EPL2/THEATER is
selected, the level will be set and locked to unity gain.
vol dn, vol up: Level setting on the Premier 17LS is achieved by using
a programmed microprocessor to select combinations from among an
array of high-quality precision resistors. This arrangement allows 100
steps of approximately .7 dB per step. The steps are numbered 0
through 99, with 0 being silence, and 99 being maximum volume.
Premier 17LS Owner’s Manual 7

The level setting can be changed by pressing the vol dn and vol up
buttons on the front panel. Each time a button is pressed, the level will
move up or down one step. If a button is pressed and held, the level
control will cycle through the steps at an accelerating rate. With each
step, a slight "click" will be heard from the opening and closing relays
insidethe Premier17LS.Balance canonly besetviatheremote control.
mute: Pressing the mute button will silence the preamplifier main
outputs,and setthe leveldisplaytozeroonbothchannels.Pressingthe
mute button again will restore the previously selected level setting.
Remote Control
All operations of the Premier 17LS can be controlled by the handheld
wireless remote unit.
MUTE: Pressing the mute button will cause the main outputs to mute
and the level display to be zero. Pressing it again will restore the last
level setting. Pressing and holding the mute button for more than three
seconds will switch the Premier 17LS into standby mode (all tube
circuitry switched off). Pressing the mute button when the unit is in
standby mode will switch it back on.
PH/AUX,TUNER, CD,VIDEO,AUX2: You candirectlyaccessanyinput
by pressing the associated button on the remote.
EPL1, EPL2: Pressing the EPL buttons will insert the associated exter-
nal processor in the signal path. Pressing the button again will re-estab-
lish a direct connection to the selected source. Note that pressing the
EPL2 button selects the THTR/EPL2 input, setting the level to unity
gain.
LEVEL - +: Duplicates the function of the front panel vol dn, vol up
controls.
BALANCE: Allows attenuation of either channel independently of the
other.Pressingthe right balancebuttonwill reduce theleftchannel level
setting by one step. Pressing and holding the right balance button will
cause the left channel to cycle down through its level settings at an
acceleratingrate. Pressingtheleftbalancebutton willattenuate theright
channel in the same manner.
Premier 17LS Owner’s Manual 8

Vacuum Tube Replacement
The Premier 17LS circuit employs four vacuum tubes (V1 - V4), all
6922s. The 6922 offers low noise, low microphonics, and gain well
suited to use in a zero-feedback line-stage. The brands of tubes we
supply have been chosen by first selecting those brands which are
known to be most reliable, then by extensive auditioning of these
acceptable brands with the final choices being made solely on the basis
of sonic performance. We know of no vacuum tubes available which will
improve the sonic performance of your Premier 17LS. The tubes in your
preamplifier have been tempered by a controlled burn-in procedure that
permits them to perform for a greatly extended period without sonic
degradation, then selected for minimum residual noise. Replacement
tubes are prepared and selected in the same way. Therefore, we highly
recommend that you purchase replacement tube sets from conrad-
johnson design.
We anticipate tube life to accommodate two to three years of operation
without degradation in normal use - if the preamplifier is switched off
when not in use. If the preamplifier is left on at all times, tube life can be
exhausted in a matter of a few months.
Premier 17LS Owner’s Manual 9

Getting The Most From Your Premier 17LS
In a system of commensurate high quality components, the conrad-
johnson Premier 17LS offers an unparalleled level of sophistication and
refinement in music reproduction. To get the best performance out of
any audio system, there are a number of important details which must
be attended to.
Absolute Phase
Musical notes are heard through the ear’s response to waves of alter-
nating rise and fall of air pressure. Musical transients are almost exclu-
sively positive: that is, the initial effect is a rise in pressure. The ear is
capable of distinguishing these positive transients from the musically
unnatural alternative of a negative transient (an initial fall in air pres-
sure). In terms of your stereo system, these transients are created by
your loudspeakers. If the speakers respond to musical transients by first
moving out, they are creating a rise in pressure, and the system is said
to be phase correct. If they respond by moving in, they create a fall in
pressure and the system is said to be phase inverting. Each component
in the stereo system either preserves the phase of the incoming signal,
and is said to be phase correct, or inverts the phase and is said to be
phase inverting. It is unimportant whether an individual component is
phase correct or phase inverting, as long as the system as a whole is
phase correct. This will be the case if the number of phase inversions is
even (or zero).
The Premier 17LS is phase inverting. If your system has an odd number
of inversions, (for example, if the Premier 17LS is the only phase
inverting unit in the chain) then you must add one phase inversion. This
is conveniently done by reversing the positive and negative connections
to your speakers (be sure to reverse both channels).
If you are not sure about the phase of every piece in your system, you
can establish correct absolute phase by careful listening. When the
system is in correct phase, transients will be noticeably cleaner and
more sharply defined. The effect is especially apparent on plucked
string sounds. A final warning - not all recordings are phase correct
(including some "audiophile" recordings), so listen to several before
concluding your investigation of absolute phase.
Premier 17LS Owner’s Manual 10

The Importance Of Wires
Interconnect and speaker wires are an important element in your stereo
system. Interconnects are available which will permit a reference quality
system to blossom and fulfill its promise of musical reality. Others will
strangle the system to the point where it becomes little better than
average. To complicate matters, our experience suggests that the
choice of interconnects will be system dependent - those that are top
ranked on one system may be a poor choice for a different system.
Consult your conrad-johnson dealer for recommendations for your spe-
cific system.
Performance Tip
Warm up the Premier 17LS before listening: The sonic performance of
the Premier 17LS improves noticeably as the unit warms up. The
midrangebecomesmore lucid,the highssmoother,and thesoundstage
expands. The warm up period can be expected to last about fifteen
minutes.
Questions: If you have questions about the installation or function of
your Premier 17LS do not hesitate to call Customer Service at (703)
698-8581.
Premier 17LS Owner’s Manual 11

Specifications
Gain: 26 dB
Maximum Output: 15V
Bandpass: 2Hz to more than 100kHz
Hum and noise: 100 dB below 2.5V output
Distortion at 1.0 v output: less than .25% THD or IMD
Phase: inverts phase of all inputs at main out
Output impedance: less than 850 ohms
Mechanical:
Dimensions: 15.25"D x 19"W x 3.315"H
Net Weight: 21 lbs total.
Fuses
The Premier 17LS has two power transformers (one for the tube
circuitry, one for the control circuits), each of which is protected by
a fuse. A failure of either of these fuses is a symptom of a more
serious problem, and a competent service technician should be
consulted. In no event should these fuses be replaced with a
value or type different than that originally supplied. The fuses
are located on the input/output pc board at the back of the chassis.
The fuses are identified as F1 and F2 on this printed circuit board.
If configured for 100 or 120V:
F1 1/2 amp, fast blow
F2 3/4 amp, slow blow
If configured for 220 or 240V:
F1 1/4 amp, fast blow
F2 1/2 amp, slow blow
Premier 17LS Owner’s Manual 12