The DH-500 Power Amplifier has been carefully en-
gineered to provide many years of use without requiring
any maintenance or servicing.
Factory assembled units are subjected to many physical
and electrical tests before shipment. The amplifier module
assemblies of kit units are similarly tested to meet perfor-
mance specifications prior to packing. In spite of this,
shipping damage does occur, a kit may not be assembled
properly, or human error interferes, so service may be
needed. The David Hafler Company provides complete
service facilities at the factory to make any necessary re-
pairs. Because many of the components in this refined de-
sign are not readily available through local sources, and
the performance of the unit is likely to be compromised
with “similar type” substitutions, we strongly recommend
factory service, or obtaining the requisite parts from the
factory.
It is the owner’s responsibility to return or ship the unit
freight prepaid to the factory service department. Units
shipped freight collect will not be accepted. For units to be
repaired under warranty, a copy of the dated bill of sale
must accompany the unit.
Use the complete original carton and all packing mate-
rial to ship
your amplifier. Enclose with the unit the follow-
ing information:
1.
2.
3.
4.
5.
Complete shipping address (Post Office box numbers
are not acceptable, except for correspondence).
The serial number, if it is not on the unit.
Copy of dated bill of sale if repairs are to be made under
warranty.
Description of the malfunction. If intermittent, be sure
to so indicate.
You may also wish to attach your address directly to the
unit, or to the line cord.
All service work is guaranteed for 90 days.
Warranties apply to the original purchaser only. The
warranty is void if the amplifier has been modified without
factory authorization; or if parts have been substituted
which, in the factory’s judgment, are not suitable; or if the
amplifier has been either physically or electrically abused,
or used for some purpose for which it was not designed or
intended.
The warranty on the transformer is void if the leads have
been cut too short for re-use. If you think the transformer
is defective, unsolder, do not cut the leads for its return.
Technical assistance to help you locate the source of a
problem may be obtained by calling the Technical Services
Department at 609-662-6084, 8am-4:30 pm E.T. It is help-
ful to know the serial number of the unit, and the results of
any tests you have performed. However, we do not rec-
ommend that you attempt your own servicing unless you
are knowledgeable in this regard.
The weight of a DH-500 (unless it includes the special
multi-voltage power transformer), when packed exactly as
it came from the factory, should be just under 50 pounds,
and may be shipped by UPS. However, be certain it is fully
protected, and insure it for the full value.
If you choose, it is possible to return only a portion of
the amplifier for factory service, with some disassembly
on your part. This assumes that you are certain the prob-
lem lies only in the returned portion, and that you assume
full responsibility for reinstalling it correctly, since a ser-
vice warranty cannot be extended for other than the actual
portion serviced. Because the transformer is so heavy, and
a problem there is most unlikely, its removal by unsolder-
ing a few leads is a logical choice. The balance of the
amplifier should be insured for at least $700. It is also pos-
sible to unsolder the module, and return it, if that is where
the only problem lies. However, it requires much more
care in packing, to protect the delicate components on the
circuit boards, and many more connections must be unsol-
dered, so there is more risk for reinstallation error. It
should be insured for $400. The service fee for the module
is $50. If you return an amplifier for service or checkout,
and it is functioning correctly, a charge will be made for the
testing time required, as well as
for packing and shipping.
WARRANTY FOR KIT-BUILT UNITS
The parts in a DH-500 kit are warranted for a full year
from the purchase date. If a defective component is found
on a circuit board or in a kit, simply return the
individual
part to the factory prepaid together with the serial
number
and the date of purchase, and it will be replaced at no
charge.
If you
cannot locate what is wrong with
your DH-500,
return it to the factory along with a copy of the dated bill of
sale, and a check for $75. If the cause of the problem is a
defective part, the unit will be repaired and returned to you
transportatiion prepaid, and your $75 less the
shipping
charges
will be returned to you. If the problem is found to
be an error in your assembly of the amplifier, the amplifier
will be put in proper working order, tested to be sure it is
meeting specifications, and returned to you (freight
prepaid within the continental U.S.). Excess shipping
charges for expedited service, or overseas delivery are
your responsibility. At the sole discretion of the factory
service department, if the time required for diagnosis,
repair and testing, and the nature of the malfunction
warrants it, a portion of the submitted repair fee may be
rebated.
This warranty is void if the kit has not been completely
assembled or if other than rosin core solder has been
used.
Units assembled with acid core solder or paste flux will be
returned unserviced.
WARRANTY FOR FACTORY ASSEMBLED UNITS
The DH-500 is warranted for three years from the
purchase date including parts and labor and normal ship-
ping costs from the factory to the owner within the conti-
nental U.S. The owner is responsible for returning the unit
to the factory and must submit a copy of the dated bill of
sale.
This warranty gives you specific legal rights. You may
also have other rights which vary from state to state.
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