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10 

11 

12

S e l e c t   the plastic encased relay, the longer
L-shaped mounting bracket, and 2 sets of hard-

ware. Insert the screws through the bracket with
the bracket foot pointing away from the lugs at the
opposite end of the relay. ‘lighten this hardware 

se-

curely, but do not risk breaking the plastic.

Select 2 sets of hardware and mount the relay near the 2
red terminals, with the bracket facing front. Install the
screws from below the chassis.

Select the 2 shorter L brackets, 4 sets of hardware,
and the circuit board 

PC-9

. Mount the brackets on

the circuit side of the board, with the feet pointing
away from the board.

Select 2 sets of hardware and install the circuit
board between the line cord and terminal RB, with

the components facing to the rear.

13 

 Select the 7-lug terminal strip and 2 sets of

hardware. Install it at the two inner holes in front of
PC-9. The hole near the right chassis edge is not
used. The mounting feet face forward.

14 

 Select the single fuse clip and a set of hardware. In-

stall it in the single hole between the two “dimples”
at the front of the chassis. The dimples prevent the
clip from turning too far.

15 

 Select the 2 dual fuse clips and 4 sets of hardware.

Install one of these in the pair of holes nearest the

center of the chassis, and the other in the pair of
holes aligned with it near the left edge.

16 

q  

Select the 3/4” long #6  screw and a nut, and the rec-

tifier diode block which has four lugs. Install the
rectifier DB in the front center hole nearest the fuse

holders. Note the lug positioning in the diagram,
and check the marked location of the + lug.

17 

 Select the two round capacitor brackets, the two

large capacitors, and 8 sets of #6 hardware. Place a
bracket around the bottom of each capacitor and
fasten it with one set of hardware through each

clamp. Note the direction of 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 and
tighten both clamps.

18 

 Select the 4 plain connecting lugs and four  l/4” long

large screws with lockwashers attached. Install
these on top of the capacitors with the lugs pointing
as in the diagram.

19 

q  

Select the two 2 amp fuses and install them in the

round fuse holdders on the back of the chassis. This
will keep the caps from being loosened and lost.

This completes the basic mechanical assembly of the
chassis. Set it aside for the present.

20 

 Select the large front plate, the smaller front panel

with the edges turned back, the two handles, and
four #lO screws. With the power switch cutouts
aligned, place the screws through the panel from

the rear, through the front plate, and secure the

handles. Set this assembly aside.

21 

 Select the amplifier module. Handle it with care!

The fan is mounted on the front of the module, with
a foam gasket on the rear. On the bottom, two
thermal sensors for the fan, and two safety thermal
breakers are already mounted on the heat sinks.
With  the module upside down, and the fan away
from you (to keep the left channel on the left, for
consistency) cut the right fan lead to 5-3/4”,  strip it

l/4”, and connect it to TS2 lug #6.

22 

 Cut the left fan lead to  4”, strip it l/4”, and connect it

to TBl lug #l.

A soldering iron will be used regularly from now on. Be
sure you wipe its tip frequently with a damp cloth or
sponge, as a bright tip will make connections easier with
less likelihood of overheating components. If it is difficult
to heat a connection in a couple of seconds, apply a small

amount of fresh solder to the tip so it can flow around the
connection and provide good heat transfer.

Содержание DH-500

Страница 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 ...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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 ...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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 ...

Страница 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...

Страница 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...

Страница 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 ...

Страница 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...

Страница 16: ......

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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 ...

Страница 22: ......

Страница 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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