Conrad-johnson Pv14l User manual

Thank you for selecting the PV14L as the control center for your audio

system. Using it, we believe that you will hear more from your favorite

recordings than ever before. Drawing on more than two decades of

researchatconrad-johnsonintothereproductionofrecordedmusic,the

PV14L line-stage preamplifier excels at the recreation of the dynamics,

textures, tonalities, and ambience of live musical performances.

Atconrad-johnson,weexpectourproductstobea source of satisfaction

and of pride to their owners for many years to come. Accordingly, circuit

designs, parts and materials have been selected with a view to main-

taining optimal performance over the years. Our reputation for produc-

ing among the industry’s most reliable components is a natural

consequence of this engineering approach.

Although the PV14L has been designed to operate in an intuitively

apparent way, you will find useful information on installation and on

operation in this manual. Please take a few minutes to read the manual

to better understand the features and capabilities of your PV14L. Note

that this unit is phase inverting. See the section entitled "Getting the

most from your PV14L" 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 PV14L, and to

provide any needed service both during, and after the warranty period.

Our goal is to heighten your enjoyment of recorded music.

PV14LS 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.

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

PV14LS Owner’s Manual 2

United States, but the customer must pay all shipping, handling and

customs costs both to and from our Service Department.

Questions about this warranty can be sent by mail to:

Service Department

conrad-johnson design, inc.

2733 Merrilee Drive

Fairfax, VA 22031

or by e-mail to: [email protected]

The Service Department can also be reached by phone at 703-698-

8581,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 pur-

chasedfromourservicedepartmentifyounolonger haveyours.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 aware that

requesting an estimate will delay service to your unit 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.

PV14LS Owner’s Manual 3

Installation

The PV14L dissipates approximately 20 watts of heat, and must be

adequatelyventilated. Mount the unithorizontallyonaflat,hardsurface,

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 recom-

mended.

All PV14Ls sold in the United States are configured for operation on a

60Hz ac power line producing between 108 and 126 volts. Export

versions of the PV14L 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 PV14L to

minimize it’s susceptibility to radio frequency interference and other

forms of EMI. Choice of materials, physical layout, grounding practice,

andpower supply designhave all beenspecified with aview 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 degradedaudio performance. Wefind that theapproach

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).

PV14LS Owner’s Manual 4

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

SOURCES (AUX1/PH, TUNER, CD, VIDEO, AUX2): These inputs are

electrically equivalent. The load presented to the source varies with the

volume control setting, but in no case will it drop below 39 kohms.

Connect the corresponding source components to these inputs.

EXTERNAL PROCESSOR LOOP (EPL1): A set of line-level inputs and

outputs are provided for the connection of external signal processors

(eg.parametricequalizer,tonecontrols).Thesecanalsobeusedforthe

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.

OUTPUT: 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 PV14L 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

PV14L" for an explanation.

PV14LS Owner’s Manual 5

Controls

power: TheredLEDimmediatelybelowthepowerswitchwillbelitwhen

the preamp is connected to the ac mains to indicate that the control

circuits are powered. Press the button labeled power to switch the

preamplifier on. A time delay auto-muting circuit is incorporated into the

PV14L to eliminate transients generated at power-on and power-off. All

outputs are grounded via relays for approximately 90 seconds after the

unit is turned on in order to suppress warm-up transient noises. During

this auto-muting period, the red mute indicator led will flash. All control

functions are disabled during the auto-muting cycle. The muting circuit

also grounds the outputs immediately at turn-off or in the event of any

power line interruption.

When first connected to ac mains, or after an interruption of power , the

PV14L will turn on, after auto-muting, in a default mode with the level

control 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.

mute: Pressing the mute button will silence the preamplifier’s main

outputs, and light the led labeled mute. Pressing the mute button again

will restore normal operation.

volume (up/down): Level setting on the PV14L is achieved by using a

programmed microprocessor to select combinations from among an

array of high quality precision resistors. This arrangement allows a

control with 100 steps of approximately .7 dB per step. The steps are

numbered 0 through 99, with 0 being silence and 99 being maximum

volume.

source selectors (aux1/ph, tuner, cd, video, aux2): Pressing any of

these buttons will select the associated source, routing it to the EPL

outputs, and to the line-stage if neither EPL nor THEATER is selected.

The selected source will be indicated by an illuminated led.

epl selectors (source, epl, theater): Pressing the epl button will acti-

vate the external processor loop. The selected source will first pass

through the external processor loop before being routed to the volume

control and line stage. Pressing the theater button will activate the

theater mode. The selected source will pass through the device con-

PV14LS Owner’s Manual 6

nected to the theater loop before being routed to the line stage. In

theater mode the level will be set and locked at unity gain for both

channels. Pressing the source button will connect the selected source

directly to the volume control and line stage.

Remote Control

All operations of the PV14L can be controlled by the hand-held 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 PV14L into standby mode (all tube circuitry

switchedoff).Pressingthe mute button whentheunitis in standby mode

will switch it back on.

PH/AUX,TUNER, CD, VIDEO, AUX2: Youcandirectlyaccessanyinput

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 down, vol up

controls.

BALANCE: Allows attenuation of either channel independently of the

other.Pressing theright balance button will reducethe left channel 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.Pressingtheleft balance button willattenuatetheright

channel in the same manner.

PV14LS Owner’s Manual 7

Vacuum Tube Replacement

The audio circuit of the PV14L uses two type 6C4 miniature triode

vacuum tubes. The brand of tubes we supply has 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 PV14L. 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 replace-

ment 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.

PV14LS Owner’s Manual 8

Getting The Most From Your PV14L

When connected to a system of high quality components, the conrad-

johnsonPV14Loffers an extraordinarylevelof sophistication and refine-

ment 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 PV14L is phase inverting. If your system has an odd number of

inversions, (for example, if the PV14L 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 speak-

ers (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.

PV14LS Owner’s Manual 9

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, it is our experience 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 specific system.

Warming Up

The sonic performance of the PV14L improves noticeably as the unit

warms up. The midrange becomes more lucid, the highs smoother, and

the soundstage expands. The warm up period can be expected to last

for about fifteen minutes to half an hour.

Questions: If you have questions about the installation or function of

your PV14L do not hesitate to call Customer Service at (703) 698-8581,

or e-mail us at [email protected].

PV14LS Owner’s Manual 10

Specifications

Gain: 22 dB

Maximum Output: 9V RMS

Bandpass: 2Hz to 100kHz

Hum and noise: 95 dB below 2.5V output

Distortion at 1.0 v output: less than .1% THD or IMD

Phase: inverts phase of all inputs at main out

Output impedance: less than 200 ohms

Mechanical:

Dimensions: 13.75"D x 19"W x 3.315"H

Net Weight: 14 lb..

Fuses

The PV14L has one fuse on the ac power line (located in the IEC

ac mains receptacle) and one fuse to protect each of it’s

transformers. Failure of any fuse 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 correct fuse

values are:

. . . . . . . . . . . .100-120V mains . . . . 230V mains

ac mains fuse . . . . . . .T800MA 20mm . . . . T400MA 20 mm

F1 . . . . . . . . . . . .1/2 amp fast blow 3AG 1/4 amp fast blow 3AG

F2 . . . . . . . . . . . .1/2 amp slo blow 3AG 1/4 amp slo blow 3AG

PV14LS Owner’s Manual 11