background image

80  0 Select the triad of black, red and yellow wires from

under the module. These will be connected to the
right end of the terminal strip, and to prevent the
heat from the large resistors from melting the insu-

lation on the wires, connect the wires from behind
the terminal strip and keep them against the chas-

sis, so the resistors will be above them. Connect

the black wire to LT lug  #5.  Connect the yellow
wire to LT lug  #6.  Connect the red wire to LT lug

#7.

81 

 Select one of the 300*  ohm 7 watt resistors. Trim each

lead to 3/4’

 

’ .

Strip two  1/Z” lengths of insulation from a

piece of heavy wire, and place one piece over each
resistor lead as insulation. Connect one lead to LT lug

#5 on the front side of the strip. Connect the other lead

to lug #6.  Because lug #6  will eventually have several
wires, it is important that each wire be placed as low as
possible in the opening, and crimped so as to maintain
the largest possible opening for the last wire.

* In these two steps, use the 600 ohm resistors instead, if the

overseas multivoltage transformer option is wired for 200  -
240 volt AC lines. See page 18. A 220 volt fan must be used,
part #AAI28,  and will have been fitted if specified.

82 

 Select the remaining 300” ohm resistor. Trim each lead

to 3/4" and place this resistor on the back side of the
terminal strip and connect one lead to LT lug #5.  (S-3).
Connect the other lead to LT lug #7. (S-2).

83 

 Select the white  wire from the left circuit board,

protruding from underneath the module. Connect it
to RY lug #7.  (S-2).

84 

 Select the long white wire from  eyelet 5 on the right

circuit board. Place it under the relay and connect it
to RY lug #9.  (S-2).

85 

 Connect the short white wire from the  left side of

the module to fuse clip FL lug #l. (S).

86 

 Connect the longer green wire from  eyelet 7 on the

left side to the bare wire between the 2 large
capacitors. (S). Place it down against the chassis.

The wiring of the amplifier is now to be completed with the
installation of the power transformer and two disc
capacitors. The following instructions refer to the 120 volt

transformer supplied for the USA. If your kit is supplied
with the optional multivoltage transformer for overseas

use, separate instructions in this manual will diagram,
both in pictorial form, and schematically, the connection
for each line voltage.

NOTE FOR MULTIVOLTAGE OPTION

The following steps which

describe the installation of the capacitors, and the connec-

tion of the two red leads, and the red/yellow lead of the
transformer are to be followed for all units. Only the con-
nections for the black and black/white transformer leads,
and the additional leads supplied on your transformer, may
differ. You should follow all the other steps to the comple-
tion of your amplifier.

91   Select the 4 sets of #10 hardware and the 4 washers,

and the power transformer. Carefully place the
transformer in position, making sure no wires are
trapped, with the transformer leads protruding to-
ward the large capacitors. You may if you choose

shorten any lead for neatness, but be sure you do
not cut any lead too short, as leads which are cut
too short for re-use may void the transformer war-
ranty. If you are using the multivoltage transformer,

be sure you leave leads long enough for possible

alternative voltage applications.

The washers are to be placed on the screws on top
of the transformer feet for stiffening. Install the
bolts near the edge of the chassis first. That will
determine which of the inner sets of holes are to be

used. It may be easiest for you to tilt the assembly
up on its right side, so the transformer weight is
supported by the work surface, or you can turn it
upside down. Be careful the transformer does not
swing into the circuit board on the module! Before
you tighten any of the mounting bolts, check to be

sure the line cord and other wires are clear of the

transformer feet.

87 

 Connect the green wire from eyelet  10  on the left

side to FL lug #2.  (S).

92 

q  

Connect the black lead to LT lug #4.  (S-3). One of

these wires has most likely already been soldered
to the lower hole of this lug.

88 

 Connect the short green wire from  eyelet 10 on the

right side to FR lug #6.  (S-2).

93 

q  

Connect the black/white lead to LT lug #6.  (S-4).

One wire has most likely been soldered to the lower
hole of this lug.

89 

q  

Connect the long green wire from eyelet 7 on the

right board to the bare wire between CL and CR.
(S). Place this wire down against the chassis. One

more connection will be made at the center of this
bare wire.

94 

 Connect the red/yellow lead to the center of the

bare wire between CL and CR. Be sure all 7 wires
are well soldered.

90 

 Connect the white wire from eyelet 3 on the same

board to FR lug #5.  (S-2).

95 

 Connect one red lead to DB lug  #l. Connect the

other red lead to DB lug #4.

Now is the best time to turn the amplifier upside down and
shake out any loose bits of solder, wire clippings, etc.

96 

q  

Prepare a  13-1/2”r ed wire. Connect one end to PC-9

eyelet  #l. (S). Place this wire down against the
chassis and connect it to DB lug #l.

13

Summary of Contents for DH-500

Page 1: ...BLOW SOME DISTORTED SOUND CAN BE HEARD THEREFORE IF AMPLIFIER MALFUNCTIONS ALWAYS CHECK FOR BLOWN FUSES FIRST LM153 3 00 THE DAVID HAFLER COMPANY 5910 Crescent Boulevard Pennsauken New Jersey 08109 Please refer to this serial number in all communications regarding this equipment ...

Page 2: ... A weighting Input Impedance 47 000 ohms Input Sensitivity 2 35 volts for 255 watts into 8 ohms 0 145 volts for 1 watt Damping Factor 200 to 1 kHz into 8 ohms 60 to 10 kHz into 8 ohms Rise Time 10 kHz 80 volts p p square wave 10 to 90 2 5 us Slew Rate 1 kHz 120 volts p p square wave 45 V us Semiconductor Complement 27 transistors 12 power Mosfets 33 diodes 8 zener diodes one integrated circuit one...

Page 3: ...t in bandwidth limitation at the input all other stages are free of any trans ient overload The fully complementary symmetrical push pull circuit is direct coupled throughout except at the input It uses all silicon discrete devices in a format which is directly re lated to the acclaimed Hafler preamplifier circuit With its unconditional stability into virtually any load and its enormous power capa...

Page 4: ...right to turn the amplifier on A red pilot lamp in the power switch signifies that it is on If it is not illuminated the most likely cause is a blown AC line fuse That is the single fuse close to the switch inside the chassis However since the amplifier uses a 15 ampere slo blo fuse and the typical home circuit is also rated at 15 amps check that as well To avoid the turn on transients generated i...

Page 5: ...ance and the higher power handling capacity would suggest a much larger fuse at the amplifier than would provide individual protection If full power tests are to be performed particularly at low load impedances fuse ratings above 10 amps may be required for the duration of the test CONNECTIONS AC The standard unit is intended for 120 volt 60 Hz opera tion If it is controlled by an AC switch on a p...

Page 6: ...n and we are certain you will find this to be so Assembly will be faster easier and more enjoyable if you have someone help you by reading the steps aloud selecting the required parts and preparing the necessary wire lengths in advance as you proceed Fatigue increases the risk of error so take a break rather than push to early completion There are relatively few separate components in this design ...

Page 7: ...ottom of the board make certain a bright shiny flow is evident from the wire onto the circuit pattern on the board Tin n ning refers to the process of applying a light coat ing of solde r to the bared wire end This k eeps all the strands secured and also makes a good connection easier Simply touch the wire with the iron for a couple seconds and apply solder Allow the excess to flow away onto the i...

Page 8: ...the cord by bending it sharply back on itself Install the strain relief as shown with the small end of the strain relief nearest the stripped end of the line cord Crimp the two halves of the strain relief around the wire at the V with heavy pliers to partially form it before in sertion into the back panel Considerable squeez ing is necessary because the thick insulation pops back quickly Then grip...

Page 9: ...insertion of the screw for easy servicing access in the future The clamp should be snug but not tight Place each assembly so the clamping screws are accessible from the front at locations CL and CR and secure each with 3 sets of hardware Then loosen the clamps and ro tate the capacitors so that each terminal is positioned as in the diagram Make sure the capacitors are seated against the chassis an...

Page 10: ...twist together the green and white wires from TBl and TB2 Place both of these wire groups off to the right of the module Then turn the module right side up with the fan away from you and the wires extending off to the left When soldering to eyelets holes on the circuit boards the wires will be connected to the outside top of the board but they must be soldered securely to the circuitry on the unde...

Page 11: ...d to PC 9 eyelet 5 S 47 0 Prepare a 12 green wire Connect one end to LT lug 3 S 3 58 q Prepare a 9 yellow wire Connect one end to PC 9 eyelet 4 S 48 0 Select one of the spade lugs Connect it to the other end of the green wire just attached to lug 3 S The proper way to connect one of the spade lugs to the wire is to bend the shorter wider set of tabs tightly around the bare wire and bend the outer ...

Page 12: ...ft side of the module Connect the black wire to the short ground lug of input socket LS S 2 Connect the yellow wire to the long lug of LS S 75 0 Select the red and black pair from the right side and connect the black wire to the short lug of input socket RS S 2 Connect the red wire to the long lug of RS S 76 0 Select the twisted white pair from the left side Connect the longer wire to the side lug...

Page 13: ...s and the connec tion of the two red leads and the red yellow lead of the transformer are to be followed for all units Only the con nections for the black and black white transformer leads and the additional leads supplied on your transformer may differ You should follow all the other steps to the comple tion of your amplifier 91 0 Select the 4 sets of 10 hardware and the 4 washers and the power t...

Page 14: ...ES IF THE COVER IS NOT SCREWED IN PLACE 102 0 Select the remaining sheet metal screws and the cover Before closing up the unit plug it in and check to see that the fan turns Because it normally operates at low voltage for low speed a new fan may need a bit of encouragement at first Any stiff ness is normally overcome after a few minutes op eration Once you are sure it turns on each time the power ...

Page 15: ... the quiescent idle current in the driver and output stages Complete circuit stability is assured by the positive temperature coefficient of the power MOSFETs The driver and output stages of the DH 500 are of the full com plementary configuration Q14 Ql5 and Q16 are N channel MOSFETs in parallel for the positive half of the signal and Q17 Q18 and Q19 are P channel MOSFETs for the negative signal h...

Page 16: ......

Page 17: ...F014 SF021 QBl15 TAl12 RPOll RPOl I TAl16 TAl17 sz113 All capacitors are 100 volt minimum unless otherwise noted Cl c2 c3 c 4 c5 C6 c 7 C8 c 9 Cl0 Cl 1 Cl2 Cl3 Cl4 Cl5 Cl6 Cl7 Cl8 Cl9 c20 c21 c22 C23 Cl01 Cl02 Cl03 Cl04 Cl05 Cl06 c401 C402 c403 c404 c405 C406 c407 C408 Dl D8 D9 DlO Dll D12 D13 D14 D15 D16 DlOl D102 D103 D104 D105 D106 D107 D108 D40 1 Ql 2 Qf3 0 Qll Q12 413 QlOl Q401 4402 4403 4404...

Page 18: ...ly the pertinent wire connections are combinations for 100 120 200 220 or 240 volt 50 or 60 Hz shown There are other wires connected to the 7 lug terminal power sources The connections which are different from the strip which are unchanged If the amplifier is to be operated with standard 120 volt connections described in the kit assembly line voltages between 200 and 240 volts a different fan part...

Page 19: ...ne 6 32 x 1 2 Screw machine l0 32 x M Screw SEMS l0 32 x 1 4 Screw sheet metal 6 x 3 8 Screw machine 6 32 x 3 4 Washer flat lO x 7 8 Washer internal tooth 1 2 Washer rubber M Wire ties nylon 4 TA116 WA016 HZ124 CL123 AC009 LR015 sz113 UH 2U Part No HZ115 HZ1 16 HKlll HK112 HK113 HK118 HA1 13 HA116 HA119 HA118 HP1 17 HA1 15 HW114 HW116 HR117 HR138 PC Part No MS153 MS154 CZ113 cz112 CE117 QDll5 RZ01...

Page 20: ... production DH 500s Select one of the screws from the bridging kit and the mounting bracket The bracket is anchored at this location flat surface up with the screw inserted fust through the single tab from inside the bracket then through the circuit board the fiber spacing washer optional and into the heat sink 11 Select the two screws and nuts and the circuit board PC 7A With the components facin...

Page 21: ...s the speaker fuses provide the same power output protection as in stereo operation but because of individual fuse variations only one fuse may blow at these levels It is best to replace both fuses if one blows a sthe other may have been weakened These installation instructions designate connections in ac cordance with the DH 500 owner s manual and pictorial diagram and use the same terminology i ...

Page 22: ......

Page 23: ...e 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 tha...

Reviews: