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62   Prepare a 3” white wire. Connect one end to RY lug

#4. (S). Connect the other end to red output termi-

nal LR. (S).

63   Prepare another 3” white wire. Connect one end to

RY lug #6. (S). Connect the other end to output

terminal RR. (S).

64   Prepare a 16”green wire. Connect one end to black

output terminal LB. (S). Connect the other end
close to the center of the bare wire between the two
capacitors. (S).

65   Prepare an 18” green wire. Connect one end to out-

put terminal RB. (S). Connect the other end to the
bare wire between the two capacitors. (S).

66 

q  

Prepare an 11-E” green wire. Connect one end to

dual fuse clip FL lug #4. (S). Connect the other end
to CR lug #4.

67   Prepare a 7” white wire. Connect one end to FL lug

#3. (S). Connect the other end to CL lug #l.

68   Prepare a 12”white wire. Connect one end to FR lug

#7. (S). Place this against the chassis and connect

it to CL lug #l.

69   Prepare a 13” white wire. Connect one end to CL lug

#l. (S-3). Connect the other end to the rectfier

block DB lug #2. (S). This is the lug on
the rectifier.

70   Prepare a 7 1/2’ green wire. Connect one end to FR

lug #8. (S). Connect the other end to CR lug #4.

71   Prepare another 8”green wire. Connect one end to

CR lug #4. (S-3), Connect the other end to DB lug

#3. (S).

72 

 Strip a 3/4" piece of light wire bare. Connect it be-

tween the short ground lug of input socket LS and
the separate ground lug between the 2 input soc-
kets.

73   Prepare a 14” black wire, but strip 3/4" of insulation

from one end. Thread the longer bared end through
the separate ground lug, and connect it to the short

ground lug of input socket RS. Solder only the two
wires at the center ground lug at this time. Place the
wire against the chassis, and connect the other end

to the bare wire between the two large capacitors.

(S). This is the 4th of 7 wires connected at this
point. Remember to leave space in the exact center
for the last wire, but keep all of these close to-

gether.

Now place the wired amplifier module behind the chassis

in line with the input sockets, so that it is resting on the
foam gasket, with the mounting feet against the chassis. Its
wires will protrude toward the chassis, or to the right.

74 

q  

Select the yellow and black twisted pair from the

left 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 

 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 

 Select the twisted white pair from the left side.

Connect the longer wire to the side lug of the fuse
holder LE (S). Connect the other wire to the tip lug
of LF. (S).

77 

 Select the twisted white pair from the right side.

Connect the longer wire to the side lug of RF (S).
Connect the other wire to the tip lug of RF (S).

Make sure that all of the unconnected long wires (except
for the green wires to eyelet 7 on each board) are placed off
to the right so that when the module is installed on the
chassis these wires will protrude between the feet below
the right circuit board. The wires to the #7 eyelets, as well
as those to eyelets 3 and 10, connect towards the front of
the amplifier. Carefully lift the module without touching
the components on the circuit boards. Swing it into posi-
tion on the chassis, and check to make sure that no wires
are trapped under the mounting feet. Make sure that the
input socket long lugs have not been bent so that any
shorts are possible there-or to the chassis. Keep all wires
away from the ‘inrush limiter’ disc-against the chassis.

It is a good idea at this time to check the fan by hand, to
make sure it rotates freely. Shipping sometimes may cause
a misalignment. If it rubs, bending a strut will correct the
problem.

78 

 Select 4 sheet metal screws and secure the module

to the chassis. The easiest procedure may be to tilt
the whole assembly backwards so that the module
is again lying on the gasket, giving you access to the
bottom of the chassis. Start the screws, and then
check again to make sure no wires are trapped be-
fore tightening the screws fully.

79 

 Select the green and white twisted pair from the

bottom of the module. Connect the green wire to
the terminal strip LT lug #l. Connect this wire to
the lower hole in that lug, and solder it separately
from the two wires which are soldered to the upper
part of the lug, Make sure all 3 wires are soldered.
Connect the white wire to LT lug #4. Use the lower

hole for this wire, and solder it separately now. Do
not solder the capacitor lead to the upper part of the
lug at this time.

12

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...

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