Velleman POWER BLOCK K8081 User manual

Total solder points: 383
Difficulty level: beginner 123 4 5⌧advanced
POWERBLOCK - POWER AMPLIFIER
ILLUSTRATED ASSEMBLY MANUAL H8081IP-1
Thisamplifierisanidealset-upforactivespeakeruse.
K8081
K8081

3
Features & specifications
This power amplifier is an ideal set-up for active speaker use.
Build a high-quality system, using two (stereo) or more (surround) amplifiers.
Due to its auto switch-on, through input signal sensing, the unit can be installed
at almost any place.
Comes complete with enclosure and transformer.
Features :
 fully discrete design using Epitaxial Darlington transistors
 includes all connectors, transformer and enclosure
 overload and short-circuit protection
 DC error protection with LED indication
 automatic switch-on upon input signal sensing (automatic switch-off)
Specifications
• 200W music power @ 4 ohm load
• 100W rms power @ 4 ohm load @ 10%THD
• distortion: 0.02% @ 1KHz/10W
• damping factor: >800
• frequency response: 3Hz to 200KHz (-3dB)
• sensitivity: 0.6V rms
• signal to noise ratio: 115dB
• power supply: 235 or 115 Vac
• Auto sensing on time : 15min.
• dimensions: 195 x 180 x 60mm (7.7" x 7" x 2.4")

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Assembly hints
1. Assembly (Skipping this can lead to troubles ! )
Ok, so we have your attention. These hints will help you to make this project
successful. Read them carefully.
1.1 Make sure you have the right tools:
• A good quality soldering iron (25-40W) with a
small tip.
• Wipe it often on a wet sponge or cloth, to keep it clean; then apply solder to
the tip, to give it a wet look. This is called ‘thinning’ and will protect
the tip, and enables you to make good connections. When solder
rolls off the tip, it needs cleaning.
• Thin raisin-core solder. Do not use any flux or grease.
• A diagonal cutter to trim excess wires. To avoid injury when cutting
excess leads, hold the lead so they cannot fly towards the eyes.
• Needle nose pliers, for bending leads, or to hold compo-
nents in place.
• Small blade and Phillips screwdrivers. A basic range
is fine.
For some projects, a basic multi-meter is required, or might
be handy
1.2 Assembly Hints :
⇒Make sure the skill level matches your experience, to avoid disappointments.
⇒Follow the instructions carefully. Read and understand the entire step before
you perform each operation.
⇒Perform the assembly in the correct order as stated in this manual
⇒Position all parts on the PCB (Printed Circuit Board) as shown on the draw-
ings.
⇒Values on the circuit diagram are subject to changes.
⇒Values in this assembly guide are correct*
0.000

5
⇒Use the check-boxes to mark your progress.
⇒Please read the included information on safety and customer service
* Typographical inaccuracies excluded. Always look for possible last minute
manual updates, indicated as ‘NOTE’ on a separate leaflet.
1.3 Soldering Hints :
1- Mount the component against the PCB sur-
face and carefully solder the leads
2- Make sure the solder joints are cone-shaped
and shiny
3- Trim excess leads as close as possible to the
solder joint
REMOVE THEM FROM THE TAPE ONE AT
A TIME !
Assembly hints
AXIAL COMPONENTS ARE TAPED IN
THE CORRECT MOUNTING SEQUENCE !

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Construction
 R1 : 330 (3 - 3 - 1 - B)
 R2 : 220 (2 - 2 - 1 - B)
 R3 : 47 (4 - 7 - 0 - B)
 R4 : 3K3 (3 - 3 - 2 - B)
 R5 : 100 (1 - 0 - 1 - B)
 R6 : 22K (2 - 2 - 3 - B)
 R7 : 120 (1 - 2 - 1 - B)
 R8 : 2K2 (2 - 2 - 2 - B)
 R9 : 680 (6 - 8 - 1 - B)
 R10 : 3K3 (3 - 3 - 2 - B)
 R11 : 3K3 (3 - 3 - 2 - B)
 R12 : 10 (1 - 0 - 0 - B)
 R13 : 18K (1 - 8 - 3 - B - 9)
 R14 : 2K7 (2 - 7 - 2 - B - 9)
 R15 : 1K5 (1 - 5 - 2 - B)
 R16 : 47 (4 - 7 - 0 - B)
 R17 : 3K3 (3 - 3 - 2 - B)
 R18 : 680 (6 - 8 - 1 - B)
 R19 : 1K (1 - 0 - 2 - B)
 R20 : 220 (2 - 2 - 1 - B)
 R21 : 470 (4 - 7 - 1 - B)
 R22 : 470K (4 - 7 - 4 - B)
 R23 : 100K (1 - 0 - 4 - B)
 R24 : 1K (1 - 0 - 2 - B)
 R25 : 1M (1 - 0 - 5 - B)
 R26 : 470K (4 - 7 - 4 - B)
 R27 : 100 (1 - 0 - 1 - B)
 R28 : 15K (1 - 5 - 3 - B)
 R29 : 470K (4 - 7 - 4 - B)
 R30 : 100K (1 - 0 - 4 - B)
 R31 : 47K (4 - 7 - 3 - B)
 R32 : 2K7 (2 - 7 - 2 - B - 9)
4. 1/4W resistors.
R...
 J
1. Jump wires.
 D1 : 1N4148
 D2 : 1N4148
 D3 : 1N4148
 D4 : 1N4148
 D5 : 1N4148
 D6 : 1N4148
 D7 : 1N4148
 D8 : 1N4148
 D9 : 1N4007
 D10 : 1N4007
Mounting Diode D11 :
 D11 : 1N4007
 Mount D11.
2. Diodes (check the polarity)
CATHODE
D...
 ZD1 : 5V1
 ZD2 : 9V1
3. Zener diodes (check the polarity)
CATHODE
ZD...

7
Construction
 IC1 : 8p
 IC2 : 8p
 IC3 : 6p
5. IC sockets. Watch the position
of the notch!
 RV1 : 1K
Bias adjustment
6. Trim potentiometer
R4
 T1 : BC640
 T2 : BC640
 T3 : BC639
 T4 : BC547
 T5 : BC557
 T6 : BC547
 T7 : BC547
8. Transistors
T1
 Make sure that transistor T7 is
bent towards diode D11.
 Make sure that the transistor and
diode leads do not touch each
other.
 C1 : 47pF (47)
 C2 : 47pF (47)
 C3 : 1nF (102)
 C4 : 680pF (680)
 C5 : 680pF (680)
 C6 : 10nF (103)
 C7 : 10nF (103)
 C8 : 47nF (473)
 C9 : 100nF (104)
 C10 : 100nF (104)
 C11 : 100nF (104)
 C12 : 100nF (104)
7. Capacitors
c...
 R33 : 3K3 (3 - 3 - 2 - B)
 R34 : 560 (5 - 6 - 1 - B - 9)
 R35 : 10K (1 - 0 - 3 - B)
 R36 : 47K (4 - 7 - 3 - B)
 R37 : 1K (1 - 0 - 2 - B)
 R38 : 10K (1 - 0 - 3 - B)
 R39 : 1K (1 - 0 - 2 - B)
 R40 : 2K2 (2 - 2 - 2 - B)
 R41 : 10K (1 - 0 - 3 - B)
 LD4 : Power (red)
9. LEDs. Watch the polarity!
LD1
CATHODE

8
Construction
 GND : 1 pin
 TEST : 1 pin
 +40V : 1 pin
 T8 : 6 pins
 T9 : 6 pins
10. Pinheaders
 R42 : 0,47
 R43 : 0,47
12. 5W resistors
R...
2mm
 LS+
 LS-
 AC RED
 AC GREY
 AC YELLOW
 AC BLUE
13. Flat receptacles
SK...
 SK5 : IN
11. Male board wire connector
 LD1 : yellow (standby)
 LD2 : Blue (on)
 LD3 : red (check)
CATHODE
IMPORTANT
Mount these LED's exactly like in the
drawing, otherwise some LED's will
not fit correctly in the front panel.
 C13 : 10µF
 C14 : 10µF
 C15 : 10µF
 C16 : 47µF / 16V
 C17 : 100µF / 50V
 C18 : 100µF / 50V
 C19 : 220µF / 16V
 C20 : 220µF / 16V
 C21 : 220µF / 16V
 C22 : 470µF / 16V
14. Electrolytic capacitors.
Watch the polarity !
C...
7mm
CATHODE
+/-3mm
LD...
1
1

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construction
Mount following diodes 15mm
above the PCB :
 D14 : 1N5404
 D15 : 1N5404
Mount following diodes 10mm
above the PCB :
 D12 : 1N5404
 D13 : 1N5404
15. Power diodes
(check the polarity)
CATHODE
D...
 RY1 : VR5V242C
( 24VDC - 5A - 2C)
16. Relay
 C23 : 3300µF / 50V
 C24 : 3300µF / 50V
17. Electrolytic capacitors.
Watch the polarity !
C...
Mount all 4 brackets,
fasten them using 6mm
M3 bolt + M3 nut
19.Brackets
brackets
brackets
 IC1 : LM258P
 IC2 : VK8081 (programmed PIC10F200-I/PG)
 IC3 : TIL111 or 4N27
18. IC's. Watch the position of the
notch!

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20. ASSEMBLY OF THE UNIT
Assembly
• cut all connections to 1.5mm
 Make sure that the solder connections don't
touch the housing.
1
• fix rubber foot in center of PCB
2
Use the colour pictures on packaging as guideline
Max. 1.5mm

11
3
• slide the PCB into the heatsink
4
• fix the PCB using 4 bolts + nut
• fix the 4 nuts inside
Assembly

12
Assembly
5
• bend C4 away from T9
• bend C5 away from T8

13
6
• apply some heat conductive silicone grease to tran-
sistor and diode.
7
• place the M3 bolt for T8 and T9
• mount the isolator to heatsink, apply grease to both sides
Assembly
M3 bolt
isolator

14
8
• bend the leads for T8 (TIP142) and T9
(TIP147) like in the photograph.
9
lock washer
6mm M3 nut
• position the transistors T8 (TIP142) and T9
(TIP147) and fix using lock washer and 6mm M3
nut.
Assembly

15
Assembly
10
• solder the connections carefully, check by trying
to move the leads after soldering
• prepare the speaker output cables (red &
black), one side with terminal + cover,
other side with eyelet connector
11 • Remove the isolation
speaker output connection set

16
• mount all connectors and fuse, check position of speaker connector
and switch holder to the rear panel
12
• position the fuse holder exactly
like in the picture
13
Assembly
rear panel inside view

17
Assembly
15
Twist the connector wire
14
• align the RCA mounting nut
• solder the 2 wire connector cable to the RCA, brown = signal ground &
red = signal.
red
brown

18
16
• connect the speaker wires exactly like in the picture ( + = red wire)
Assembly
• insert 2 A slow blow fuse
17
18
• cut 3 pcs. of 3cm
from the shrink tube
3cm 3cm 3cm

19
19
• solder one 8cm brown wire to the switch and one to the fuse holder
Assembly
20
• slide a piece of shrink tube over the transformer mains connections :
 black wire
 brown wire (100-120VAC) or the orange wire (220-245VAC)
• connect the black wire to the power switch
• connect the orange (~230VAC) or brown (~115VAC) wire with the
center connector of the fuseholder.
21
• slide the shrinking tube over the
switch and fuse holder

20
22
• isolate the not used transformer wire using a piece of tape.
Assembly
23
• shrink the tube using heater or hair dryer.