Krell MDA-300, MDA-500 Owners manual
A. INTRODUCTION
Thank you for your purchase of the KRELL MDA-300 or
MDA-500 power amplifiers. These amplifiers represent
the latest evolution in amplifier technology and incorpo-
rate many innovative design features.
To obtain the best performance from your MDA-300/
500s, careful attention should be paid to placement,
installation and operation. A thoro~ugh understanding o.f
these details will help insure satistactory op.eration and
long life for the MDA-300/500s and related system com-
ponents.
This Owner’s Reference is divided into several sections,
eac.h designed to perfo__r~_, a different function. As you
.read through this. O.w.ner s Reference you will become
better acquainted with the features and functions that
make the MDA-300/500s a superb value. A Question and
Answer section is also included where answers to common questions are provided. Should you have any questions or suggestions please feel free to contact your authorized dealer or the KRELL staff for assistance.
In the unlikely event that your MDA-3.00/50.0s should
require service you will be pleased to ~now ~tlaat it is .
backed by a.comprehensive Customer batistaction.policy
and one of the most advanced service facilities in the
industry. For detailed information on the terms and con-
ditions of service, please consult your warranty reg.istra-
tion card, your authorized KRELL Dealer or Distributor.
TABLE OF CONTENTS
4. UNPACKING AND ASSEMBLY
BASIC INSTALLATION AND OPERATION
INPUT AND OUTPUT CONNECTIONS
8. AMPLIFIER OPERATION
9. PROTECTION CIRCUITRY
10. REAR PANEL DES CRIPTIONS
12.
14. SPECIFICATIONS
15. WARRANTY AND SERVICE INFORMATION
QUESTIONS AND ANSWERS
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B. UNPACKING AND ASSEMBLY
NOTE: Do to the extreme weight of the MDA-300 or
MDA-500 it is strongly advised that unpacking and
placement is completed by at least two individuals.
1. Open the box on one end.
2. Fold back the flaps on all four sides of the box and
carefully roll it over on to the exposed end.
3. Pull the box straight up and off exposing the foam
packing material.
4. Pull the foam piece from the exposed end of the amplitier.
5. Roll the amplifier carefully onto its handles and remove the second piece of foam.
The following items will now be visible in each box:
1
1 Warranty card
1
4 or 5 Rubber bottoms (MDA-500 has 5 feet)
NOTE: If any of these items are not included please
contact your authorized dealer immediately f6r assistance.
6. Remove the plastic bag from the amplifier.
7. Repeat procedure for the second amplifier.
NOTE: Save all pac.kin~g materials..If you must ship your
MDA-300/500s in the tuture, repack the unit in its original packaging to prevent transit damage.
CAUTION: Do not connect the power cords into the AC
mains before completing the Installation section.
MDA-300/500 monaural amplifier
AC power cord
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C. BASIC INSTALLATION
AND OPERATION
1. Place the MDA-300/500, on a firm level surface away
from excessive dirt or moisture. Ideally the amplifiers ’
should be placed as close, to the speakers as possible. ,It is
always preferable torun long interconnect cables to tt~e
amplifiers and keep speaker cable length t.o a minimu~m..
Speaker cable does add an impedance at tt~e output ot the
amplifier, regardless of the cable. All KRELL amplifiers
will drive the lowest im. p.edances with ease. When impedance is added, the amphfier’s power is litera.lly wastedin
driving cable. Long speaker cables reduce tlae maximum
power that can be dehvered to the speakers.
2. Amplifiers dissipate much of the power they consume
in heat. The MDA-300/500s should-be installed in a
location that.provides unobstructed ventilation. If you
have to install the units on shelves or in a cabinet, extra
ventilation m~¢ be necessary_. This can be accomplished
with "whisper - type fans. Consult your dealer for assis-
tance.
Generally, with the front and rear of a cabinet open, 2-3
inches of clearance on each side and 8 inches of clearance above the amplifiers should provide adequate ventilation.
The exact dimensions for the MDA-300 and MDA-500
are in the Specifications Section below.
3. The MDA-300/500s should have a dedicated 20.amp.
line for each amplifier and should only be operated with
the power cords supplied. Use of other power cords may
damage the amplifiers or void its warranty. Please consult
KREEL or your dealer BEFORE using any devices designed to alter or stabilize the AC pow.er fbr.the MDA300/500s. If you have any questions about placement or
AC power conditions please consult KREL-L.
4. The feet on the MDA-300/500s canbe used in several
different ways. They are made from machined Delrin and
are supplied witla separate threaded rubber b~ottoms. The
rubber bottoms can be screwed into the feet tor protec-
tion of fragile surfaces such as hardwood floors or furniture. For use on rugs, we recommend using the fee.t with-
out the rubber bottoms. MDA-300/500s feet can also
accept the KREL. L AMDs (A, coustic Mass Damper).
These improve the amplifier s sonic performance in most
installations.
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