Conrad-johnson design PV 7 Manuel utilisateur

OWNER'S MANUAL

PV 7

VACUUM TUBE PREAMPLIFIER

conrod-johnson design, inc.

703-698-8581

Thank you for purchasing the conrad-johnson model PV7 vacuum tube preamplifier.

We believe that it will be one of the most satisfying purchases of audio equipment

that you will make.

The PV7 was designed to provide audiophiles with a moderately priced preamplifier

of high quality which would accurately reproduce the dynamics, tonalities and

textures of a live musical performance. The design and materials have been carefully

selected to yield many years of unvarying excellence.

Please take a few minutes to read this manual so that you will better understand the

use of your PV7.

LIMITED WARRANTY FOR THE conrad-johnson PV7

1. conrad-johnson design, inc. warrants to the original purchaser that the conrad-

johnson PV7 will perform to specifications as published in the owner's manual

and that it will be free of defects in materials and workmanship for a period of

three years from the date of original purchase.

2. conrad-johnson will repair defective units without charge for labor or parts (with

the exception of the vacuum tubes) subject to the following conditions:

a) The unit must not have been altered or damaged through misuse, abuse,

negligence, accident, or improper operation.

b) The purchaser must provide evidence of purchase at the time service is

requested.

c) All repairs must be undertaken at the factory or other service center

designated by conrad--johnson design, inc. Units submitted for warranty

repairs must be shipped in the factory packing carton to conrad-johnson

design or its designated service center, freight and insurance prepaid by the

owner, and will be returned to the owner, freight and insurance prepaid by

conrad-johnson design. Replacement cartons are available from the factory

for a nominal charge.

d) Normal wear and maintenance are not covered by this warranty.

3. The above warranty may be transferred to subsequent owners provided that the

warranty registration card has been returned to conrad-johnson design, inc.

within 30 days of the original purchase and that the registered owner provides the

factory with a signed notice giving the new owner's name and address and the

model and serial number of the unit.

4. Where permitted by law, conrad-johnson design's liability shall be limited to that

set forth in this warranty. No other warranty of any kind, expressed or implied, is

made by conrad-johnson design, inc., and all implied warranties, including

merchantability and fitness for a particular "purpose", which exceed the

obligations and time limits set forth herein are hereby disclaimed. conrad-

johnson design, inc. shall not be liable for-incidental or consequential damages.

Some states do not allow the exclusion or limitation of incidental or

consequential damages, or limitations on how long an implied warranty lasts, so

the above limitation or exclusion may not apply to you.

5. This warranty gives you specific legal rights, and you may also have other rights

which vary from state to state. Questions about warranty service should be

addressed to:

conrad-johnson design, inc.

2733 Merrilee Drive

Fairfax Virginia 22031

703-698-8581

ABOUT conrad-johnson design

Conrad-Johnson Design offers exclusively audiophile audio components. We believe

that our commitment to the purchaser of our products is nearly unique in the industry.

The services we offer to conrad-johnson owners include:

•Information - Registered owners of conrad-johnson equipment will be directly

informed of new equipment we have to offer. They will also be informed of any

significant changes in the design of their equipment resulting from our ongoing

development program.

•Factory updating - Should significant design changes be made, conrad-johnson

design will, whenever practical, offer to update existing equipment. This service

will be offered at a minimal charge to cover parts, labor, and handling.

•Factory service - Any conrad-johnson product may be returned to the factory for

service. All equipment serviced at the factory will perform to its published

specifications when returned. Factory service will be offered at reasonable rates.

•Transferable warranty - conrad-johnson design guarantees its products, not the

owner. Should you decide to sell the product, the warranty may be transferred to

the new owner. (See Registering the Warranty).

REGISTERING THE WARRANTY

Please return the enclosed card to the factory within 30 days of purchase to register

the warranty. The warranty may be transferred to a new owner if it has been properly

registered initially and if the registered owner sends a signed notice providing the

name and address of the new owner and the model and serial number of the unit.

Proper registration of the warranty is important! Not only will it preserve

transferability of your warranty, it will also enable us to inform you of any alterations

in the design of a given model and of any new products we offer which are likely to

be of interest to you.

CIRCUIT DESIGN

The phono stage of the PV7 consists of two cascaded triode amplifiers direct coupled

to a cathode follower for low output impedance. Phono equalization is accomplished

by R-C networks in a direct coupled feedback loop driven by the cathode follower.

The RIAA components are 1% tolerance, with RIAA capacitors being polystyrene

dielectric. The audio circuitry is executed entirely with precision, low noise metal

film resistors. All coupling capacitors are polypropylene dielectric. The line stage

consists of a single voltage amplifier direct coupled to a cathode follower with an

overall feedback loop.

Plate voltage is supplied by a sophisticated, low impedance voltage regulator. The

regulator's output supplies the audio circuitry directly to minimize power supply

source impedance. The regulator is designed using solely polypropylene capacitors,

isolating the audio circuitry from the non-linear effects of electrolytic capacitors.

Filaments are operated on a regulated d.c. voltage to minimize noise at the low signal

levels in a preamplifier and to prevent line voltage fluctuations from coupling

infrasonic disturbances to the audio signal.

INSTALLATION

Because of the number and type of vacuum tubes used, the PV7 dissipates a

significant amount of heat (approximately 30 watts). It is essential therefore, that

proper attention be paid to ventilation. The unit should be mounted horizontally on a

flat hard surface so that the ventilation holes in the bottom are unobstructed. At least

three inches of clearance should be provided above the unit and the cabinet or shelf

should be open at the back. Vertical installation is not recommend.

To minimize hum pickup, keep the unit well away from the power amplifier, and

route power cords away from input cables.

THE PV7 IS TO BE OPERATED ONLY ON AC LINE VOLTAGE OF 108 to 125

VOLTS, 50 or 60 HZ

In any system of audio electronics minute leakage currents from the ac line

transformers will flow in the signal ground connections between preamplifier and

amplifier. These currents can intermodulate with the signal and affect the clarity of

sound. Generally, one orientation of the line cord will provide much lower current

flows. When combined with the finest associated equipment this effect is clearly

audible with the PV7. After installing the unit try reversing the line cord at the wall

outlet to pick the most satisfactory orientation.

CONNECTION

Inputs:

Phono - The phono inputs provide the additional amplification and RIAA

equalization required by most high fidelity cartridges. The input impedance is 47,000

ohms shunted by approximately 140 picofarads capacitance. This is the industry

standard load and will work well with most moving magnet cartridges and all pre-

preamplifiers for moving coil cartridges. A few moving magnet cartridges perform

better with a 10,000 ohm load which may be achieved by having a service technician

shunt the phono inputs with 12,000 ohm resistors.

For some moving magnet cartridges, optimum performance requires higher

capacitive loads. This may be achieved by soldering suitable value capacitors across

the phono input jacks. Polystyrene capacitors are recommended for this purpose.

Tuner, Auxiliary, Tape 1 Tape 2 - These are all high level inputs and are

electronically equivalent. The outputs of your tape recorders should be connected to

Tape 1 and Tape 2.

Outputs:

Record 1, Record 2 - Connect these to the inputs of your tape recorders.

Output 1 Output 2 - Connect to the inputs of amplifiers with impedance of l0k-ohms

or greater.

AC OUTLETS

Two ac outlets are provided for your convenience: they are unswitched (always live).

THE TOTAL CURRENT REQUIRED OF THE OUTLETS MUST NOT EXCEED

5 AMPERES. This precludes the use of these outlets for high powered amplifiers.

OPERATION

Turn on: Because of the delayed warm up characteristics of vacuum tube equipment,

a time delay muting circuit is incorporated in this preamplifier. Output 1 and Output

2 are grounded via a relay for approximately 45 seconds after the unit is turned on in

order to suppress warm up transient noises. The relay grounds the outputs again

immediately at turn off or in the event of any power line interruption.

Selector: Use the selector switch to.choose an input from Phono, Tuner, Tape l, Tape

2 or Auxiliary inputs. The selected source will be available at the source (out)

position of the tape monitor switch and at both Record Outputs. Note that dubbing

between tape decks is possible in both directions. Also, since the selected decks'

output is fed back to its own record input, care must be taken not to select a tape deck

which is in the record mode. Similarly, if one of the tape loops is used for an external

signal processor, that tape loop should never be selected (and, of course, there is no

reason to select it since the external processor is not itself a program source). Failure

to observe these precautions will create an unstable feedback system and may

generate a "howling" sound.

Monitor: This switch permits you to compare source and tape while recording on

either or both tape decks from the selected input. You may wish to use Tape 2 and

Record 2 to install an external signal processor such as graphic tone controls. Then,

the Tape 2 position will choose the processed signal while Source will choose the

pure signal.

Balance: Permits continous control of location of stereo image from left to right. In

the full counterclockwise position only the left channel will be heard. Similarly, the

full clockwise position will reproduce only the right channel. In normal use this

control will be centered.

Volume: The PV7 volume control Is an extremely precise control, maintaining

channel to channel tracking within t 1/2 db throughout its rotation.

VACUUM TUBES

The audio circuit of the PV7 uses five vacuum tubes of two different types: three

12AX7 (V1, V2 and V4) and two 12AT7 (V3 and V5). Each type has been

carefully chosen for its circuit application. It is well known that tubes of a given type

vary sonically depending on the manufacturer. We have chosen the brands of tubes

that we supply based on extensive auditioning of available brands. The choice of

brand has been made solely on the basis of sonic performance without regard to

either cost or prestige. We know of no vacuum tubes available of the specified types

which will improve the sonic performance of your PV7. Also, 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. We anticipate

two to three years of operation without degradation in normal use. We highly

recommend that, when the time comes to replace the vacuum tubes, you purchase

replacement tube sets from conrad-johnson design.

Please note: Substitution of 12AX7 type for the type 12AT7 is likely to damage the

12AX7. Other tube type substitutions may damage the preamp circuitry or

transformer.

TUBE LOCATIONS:

Tube complement:

V1,V2,V4: 12AX7

V3,V5: 12AT7

Fuse: The AC line is fused to protect the transformer. This fuse will not fail in normal

operation. Failure of the fuse is a symptom of a more serious problem, so the unit

should be taken to a qualified Service Center. IN NO EVENT SHOULD THE FUSE

BE REPLACED WITH A FUSE OF DIFFERENT TYPE OR RATING THAN

THAT SUPPLIED BY THE FACTORY.

V2 V4

Table des matières

Autres manuels Conrad-johnson design Amplificateur

Conrad-johnson design

Conrad-johnson design Sonographe SA120 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design Premier Ten Manuel utilisateur

Conrad-johnson design

Conrad-johnson design PV4 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design CAV45 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design MV125 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design PREMIER THREE Manuel utilisateur

Conrad-johnson design

Conrad-johnson design Sonographe SC-1 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design MOTIF MC9 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design Evolution 20 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design MV50 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design Premier 140 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design PREMIER 15 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design PREMIER SIX Manuel utilisateur

Conrad-johnson design

Conrad-johnson design ET2 Vacuum Manuel utilisateur

Conrad-johnson design

Conrad-johnson design MOTIF MS1001 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design LP125M Manuel utilisateur

Conrad-johnson design

Conrad-johnson design CT5 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design Motif MS2001 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design MV45A Manuel utilisateur

Conrad-johnson design

Conrad-johnson design One-b Manuel utilisateur

Conrad-johnson design

Conrad-johnson design PREMIIER TWO Manuel utilisateur

Conrad-johnson design

Conrad-johnson design MV52 Manuel utilisateur

Conrad-johnson design

Conrad-johnson design PREMIER SEVEN Manuel utilisateur

Conrad-johnson design

Conrad-johnson design MV60 Manuel utilisateur

Manuels Amplificateur populaires d'autres marques

ASTRO

ASTRO HVO V40 P Manuel utilisateur

Marantz

Marantz SUPERSCOPE BLA-545 Instructions de montage

NAD

NAD CI980 Manuel utilisateur

Technics

Technics SE-CH770 Manuel utilisateur

Harman Kardon

Harman Kardon HK6300 Manuel utilisateur

NAD

NAD T975 Manuel utilisateur

McIntosh

McIntosh MA6850 Manuel utilisateur

Electro-Harmonix

Electro-Harmonix ENGLISH MUFF’N Manuel utilisateur

Viatron

Viatron Autrix Manuel utilisateur

GME

GME GA9800 Manuel utilisateur

Atlas

Atlas CP700 Manuel utilisateur

Roland

Roland KC-1000 Manuel utilisateur

Pyle

Pyle PFMRA350BW Manuel utilisateur

Advantage

Advantage S-250 Manuel utilisateur

IRT Electronics

IRT Electronics DVA-3007 Manuel utilisateur

Dimavery

Dimavery BA-100 Series Manuel utilisateur

Sony

Sony XM-S400D Manuel utilisateur

Schertler

Schertler ROY X Manuel utilisateur