Conrad-johnson design PREMIER 15 User manual

Thank you for selecting the Premier Fifteen as the phono stage for your
audio system. We believe that you will experience, as we did, the
excitement of discovery in hearing more from your favorite lps than ever
before. The Premier Fifteen draws on two decades of research at
conrad-johnson into the reproduction of recorded music. The result is a
phono preamplifier that sets a new standard for the recreation of the
dynamics, textures, tonalities, and ambience of live musical perfor-
mances.
Atconrad-johnson,weexpectourproductstobeasourceofsatisfaction
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 operation of the Premier Fifteen is quite straightfoward,
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 under-
stand the features and capabilities of your Premier Fifteen.
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 Fifteen,
and to provide any needed service both during, and after the warranty
period. Our goal is to heighten your enjoyment of recorded music.
Premier Fifteen 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 Fifteen 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 e-mail
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.Beawarethatrequestinganestimatewilldelayservicetoyourunit
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 Fifteen Owner’s Manual 3

Installation
The first step is to remove the transit screws. To minimize microphon-
ics, the critical audio circuits in the Premier Fifteen are on a sub-chassis
that is mounted to the main chassis with flexible isolation mounts. To
prevent damage during shipping, this assembly is secured by four
screws through the bottom of the chassis. These transist screws can be
readily identified as the four silver screws on white nylon washers.
Before installing your Premier Fifteen, remove these four screws to
release the suspension. Save these screws to re-use if it becomes
necessary to ship your Premier Fifteen.
Set Up
The Premier Fifteen dissipates sufficient heat that it must be adequately
ventilated. Mount the unit horizontally on a flat, hard surface, and take
care that the ventilation holes in the bottom are unobstructed. Allow at
least two inches of clearance above the unit and keep the cabinet or
shelf open at the back. Vertical installation is not recommended.
All Premier Fifteens sold in the United States are configured for opera-
tion on a 60Hz ac power line producing between 108 and 126 volts.
Export versions of the Premier Fifteen will have the correct operating
voltage 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.
Electromagnetic Interference (EMI)
Considerable care has been taken in the design of the Premier Fifteen
to minimize it’s susceptibility to radio frequency interference and other
forms of EMI. Choice of materials, physical layout, grounding practice,
andpower supply design haveall been specified witha view to 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
theexpense of degraded audioperformance. We find thatthe approach
we have taken has worked extremely well, resulting in only rare in-
Premier Fifteen Owner’s Manual 4

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.
Connection
Input: Connect your tonearm leads to these inputs. The load presented
to the cartridge is determined by the internal load switch. See explana-
tion below.
Output:Connecttheoutputsto anylinelevelinputonyour preamplifier.
Premier Fifteen Owner’s Manual 5

Input Impedance
To select an input load impedance other than the factory preset 47
kohms unplug the Premier Fifteen, and remove the cover. The input
impedance of the Premier Fifteen is set by the load selector switches -
the two dual inline pin (dip) switch arrays located near the input connec-
torsatthe back of theunit.Eachdip array includesfourswitcheslabeled
1 through 4. Load impedances are selected as follows:
impedance switch #
1 2 3 4
47 kohms o o o o
9.6 kohms x o o o
1.9 kohms o x o o
500 ohms o o x o
200 ohms o o o x
x indicates switch in "on" position
o indicates switch in "off" position (indicated by arrow on switch)
Be sure to set both switches. Replace cover. Do not operate the unit
with the cover off.
The factory preset 47K load (all switches off) will be best suited to most
cartridges.
Premier Fifteen Owner’s Manual 6

Getting The Most From Your Premier Fifteen
In a system of commensurate high quality components, the conrad-
johnson Premier Fifteen 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 Fifteen is phase correct. If your system has an odd number
of inversions, then you must add one phase inversion. This is conven-
iently 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 Fifteen Owner’s Manual 7

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 Fifteen before listening: The sonic performance
of the Premier Fifteen improves noticeably as the unit warms up. The
midrangebecomesmore lucid, the highs smoother,andthesoundstage
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 Fifteen do not hesitate to call Customer Service at (703)
698-8581.
Premier Fifteen Owner’s Manual 8

Vacuum Tube Replacement
The Premier Fifteen circuit employs eight vacuum tubes, six 12AX7s
and two 6GK5s. 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 Fifteen. The tubes in your preamplifier have been
tempered by a controlled burn-in procedure that permits them to per-
form for a greatly extended period without sonic degradation, then
selected for minimum residual noise. Replacement tubes are prepared
andselectedinthesameway.Therefore,wehighlyrecommendthatyou
purchase replacement tube sets from conrad-johnson design.
We anticipate tube life to accomodate 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.
Tube Chart:
V3 V4
V1 V2
V8 V7
V6 V5
front panel
Premier Fifteen Owner’s Manual 9

Specifications
Gain: 53 dB
Maximum Output: 10V
RIAA Equalization: within .25 dB
Hum and noise: 85 dB below 10 mV input
Phase: phase correct
Ouput impedance: less than 200 ohms
Tube Complement: 6 x 12AX7, 2 x 6GK5
Mechanical:
Dimensions: 15D x 19W x 3.315H inches
Net Weight: 22 lbs.
Fuses
The Premier Fifteen has two power transformers (one for the tube
circuitry, one for the control circuit), 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 small pc board mounted near the larger power
transformer. F1, the fuse for the tube circuit transformer is located
nearest the transformer cover. The correct fuse values are:
If configured for 100 or 120V:
F1 3/4 amp, slow blow
F2 1/2 amp, fast blow
If configured for 220 or 240V:
F1 1/2 amp, slow blow
F2 1/4 amp, fast blow
Premier Fifteen Owner’s Manual 10