Magnet PR-7 User manual

Magnet PR-7
Pre-amplifier
Operation Manual
Magnet Technology Corporation
Showroom: Room 509, 5th floor, Hi-Fi Center, Rajdamri Road,Patumwan, Bangkok 10330
Thailand., Tel: [phone] Fax: [phone]
Head office: 45/11-12 Soi boonnark, Sukhonthasawat Rd, Lardprao, Bangkok, 10230,
Thailand. Tel: [phone] Fax: [phone]
Website: www.magnet.co.th Email: [email protected]

1
IMPORTANT 1
The lightning flash with arrowhead, within an
equilateral triangle, is intended to alert the
user to the presence of uninsulated
“dangerous voltage” within the product’s
enclosure that may be of sufficient magnitude
to constitute a risk of electric shock to persons
.
CAUTION:
TO PREVENT THE RISK OF ELECTRIC
SHOCK, DO NOT REMOVE COVER (OR
BACK). NO USER-SERVICEABLE PARTS
INSIDE. REFER SERVICING TO QUALIFIED
SERVICE PERSONNEL.
The exclamation point within an equilateral
triangle is intended to alert the user to the
presence of important operating and
maintenance (servicing) instructions in the
literature accompanying the appliance.
WARNING: TO PREVENT FIRE OR SHOCK HAZARD, DO NOT OPEN OR
EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.
(FOR CANADIAN MODEL)
CAUTION: TO PREVENT ELECTRIC SHOCK DO NOT USE THE
PROVIDED AC PLUG WITH AN EXTENSION CORD, RECEPTACLE OR
OTHER OUTLET UNLESS THE BLADES CAN BE FULLY INSERTED TO
PREVENT BLADE EXPOSURE.
AVIS: RISQUE DE CHOC ELECTIQUE. NE PAS OUVRIR.
ATTENTION: POUR PREVENIER LES CHOCS ELECTRIQUES NE PAS
UTILISER CETTE FICHE POLARISEE AVEC UN PORLONGGATUER, UNE
PRISE DE COURANT OU UNE AUTRE SORTIE DE COURANT, SAUF SI
LES LAMES PEUVENT ETRE INSEREES A FOND SANS EN LAISSES
AUCUNE PARTIE A DECOUVERT.

2
Preface
Thank You for purchasing the Magnet PR-7 Pre-amplifier. You have selected a component which
has been designed to exacting standards to provide you with years of listening pleasure. It is
important to remember that all Magnet’s products can provide high quality sound, if you take
proper care in setup. Your selection of associated components and cables is critical to the results
which you will experience. Careful room set-up of your audio equipment is also necessary to
realize all the potential from the your audio system.
As with all Magnet’s products, the PR-7 has been carefully designed, manufactured and tested to
ensure Magnet’s high quality and reliability. This is a product that you can be sure of sound,
quality and high value. We wish you many happy memories with MAGNET.
The PR-7
The PR-7 is a Dual-Mono Solid State Pre-amplifier. With total separation of power supplies, filters
and amplifying circuitry, the PR-7 produces minimal cross-talk and distortion from modulating
signal between audio channels. Further more, the double sided Glass Epoxy PCB provides a full
surface ground plane to reduce any other stray capacitance or inductance coupling and eliminate
RF interference at all points in the circuit. With an accurate frequency response of less than +/-
0.05 dB from 20-20,000 Hz and THD+NOISE of less than 0.01%, the PR-7 specifications show
how precisely the PR-7 can reproduce your music. The PR-7 creates a clear and warm midrange.
Bass sound is low and tight. You can be sure every sound you hear is an accurate reproduction of
the original performance.
All components and accessories are audiophile grade and many are specifically designed for high-
end audio. 1% tolerance metal film resistors, Wima capacitors, gold plated RCA jacks,
aluminum anodized faceplate and full aluminum chassis are just a few features for those of you
who are looking for a quality Hi-end product.
The PR-7 is an excellent quality product representing Magnet goal of providing audiophiles with
affordable high-end products.
Precautions
Before proceeding with the installation, please read the instructions carefully to avoid damage
during operation. If you have any problems, do not hesitate to contact our Sales or Service
Department.
Save this Operation manual for latter reference.
1. All warnings on the unit and in the operation manual should be adhered to.
2. This unit should not be used near water or in humid condition.
3. Do not touch any parts inside the machine in order to avoid electric shock.
4. The operating temperature range is +5 to +35 °C. Operating humidity is 5% to 80%. Do
not operate the unit when the temperatures and/or humidity are outside of this range.
5. Before connecting or disconnecting any cables, always turn off your equipment.
6. Before turning the power ON/OFF, turn your volume control to the lowest output level.

3
Connections
Note : make all connections to and disconnection from the PR-7 with AC Power disconnected
and all system components switches “OFF.”
INPUTS The PR-7 has a total of 7 line level inputs.
1. GND Ground point for special ground requirement such as Turn Table.
2. PHONO receive signal from Turn Table Record player.
3. TUNER receive signal from Tuner.
4. CD receive signal from Compact Disc player.
5. LASER receive signal from Laser Disc player.
6. VIDEO receive signal from audio out of VCR.
7. AUX receive signal from line level input.
8. TAPE receive signal from Cassette Tape player.
REC (Recording output monitor)
9. REC- Send output signal from selected program source to Cassette tape input. To record from
the program source onto Cassette tape, turn the selector switch to the source program you
wish to record and press record on the cassette tape player.
OUTPUTS The PR-7 has 2 outputs for connection to power amplifier.
10. OUTPUT 2 Sends signals to power-amplifier (use in bi-amp application).
11. OUTPUT 1 Sends signals to power-amplifier.
12. AC OUTLET This is an unswitched ( not controlled by the front panel POWER switch) AC
out. Maximum output current is 1 Amp.
13. FUSE Replace only with same type of fuse and rating as marked on the rear panel.
14. AC POWER Connect the PR-7 to an AC power source only of the type describe in these
operating instruction or as marked on the rear panel of the unit.

4
Functions
1. POWER Pressing the POWER button once on the front panel will turn the machine on.
The LED on the front panel will light up when the machine in ON. The PR-7 will remain in
mute for approximately 4 sec after turning on to allow for component stabilization. The
power LED will be dimly lit while the machine is on MUTE. The LED will be fully lit when
the machine is out of mute and ready to play.
Press POWER again to turn the machine OFF. The LED will fade off when the power is off.
2. BALANCE Turning the balance level will lower your output level left/right. Leaving it in
the center will give you equal output on both channels. Sometimes in unequal source
recording, you may need to adjust the balance level to get a balanced stereo image.
3. TREBLE For adjustment of higher tone. Turning the TREBLE level will boost or cut the treble
level of your output . Leaving it in the center will give you a flat frequency response output.
4. BASS For adjustment of lower tone. Turning the BASS level will boost or cut the bass
level of your output . Leaving it in the center will give you a flat frequency response output.
5. TONE Press the TONE switch to activate TREBLE and BASS circuitry. When not engaged
( not pressed in) the signal will bypass the TONE circuitry.
6. TAPE Press the Tape switch once to select TAPE input as the source. Press TAPE once more
to un-selected TAPE mode.
7. VOLUME For adjustment of the output level.
8. CD/TUNER/LASER/VIDEO/LINE1/LINE2 Turn the select knob to your desired source input.

5
Specifications
Phono Input Impedance 47K Ohms,100pF
Voltage Input for 150mV Output 2.5mV
S/N A-weighted 75 dB
Maximum Input Voltage 250 mV
RIAA Accuracy +/- .5 dB
Line Amp. Input Impedance 20K Ohms, 220pF
Voltage Input for 900mV Output 150 mV
S/N A-weighted 85 dB
Maximum Input Voltage 2.5V
Frequency Response (20-20,000Hz) +/- 0.05 dB
THD+Noise 0.01%
Tone Control Boost and Cut +/- 10 dB
Maximum Output at 1K 14 Vrms
Input Power As marked on the rear panel
Power Consumption 7 Watts
Size 17"W x 2.75”H x 14”D
Weight Net 2.4 Kg, Shipping 3.4 Kg
Warranty Information
1. MAGNET Technology Corporation(hereinafter referred to as MAGNET) warrants to the
original retail purchaser only, that its product is free from defects in material and
workmanship under normal use and authorizes free service and/or parts exchange at any
MAGNET Authorized Service Station only, for a period of ONE year from the date of
purchase.
2. The warranty is subjected to the following conditions and limitations. The warranty is void :
if product has been used other than in accordance with the instruction in the owner’s
manuals: abused or misused or is due to the product being repaired or tampered with by
anyone other than Magnet Technology Corp. or an authorized repair center.
3. The warranty does not apply to defects or failure caused by unauthorized parts, improper
maintenance, fire, flood, lightning or other natural causes.
4. This warranty does not include the damage of external parts i.e., faceplate, knobs, metal
casing, etc.
5. A returned product must include a copy of the Warranty Certification and the bill of sale.
6. The warranty does not extend to any incidental nor consequential cost or damages to the
purchaser.

6