Velleman K8021 User Manual

Total solder points: 500
Difficulty level:

beginner 1o 2o 3o 4o 5þ advanced

HIGH-END CONTROL AMPLIFIER

K8021

ILLUSTRATED ASSEMBLY MANUAL H8021IP-1

VELLEMAN KIT NV

Legen Heirweg 33

9890 Gavere

Belgium

http://www.velleman.be

Assembly hints

0.000

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 compo­nents 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*

3

Assembly hints

⇒ 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 cone­shaped and shiny

3- Trim excess leads as close as possible to the
solder joint

AXIAL COMPONENTS ARE TAPED IN

THE CORRECT MOUNTING SEQUENCE !

REMOVE THEM FROM THE TAPE ONE AT A

TIME !

4

5%

4K7= ( 4 - 7 - 2 - B )

1%

4K7= ( 4 - 7 - 0 - 1 - 1 )

COLOR= 2… 5

C

O

D

KODE

KLEUR

CODIFI-

CATION

DES

CODE

COLOUR

FARB

KODE

KODE

FARGE-

KODE

FARVE-

Color code table

E

COU-

I P E SF S DK N D GB F NL

FÄRG

SCHEMA

VÄRI

KOODI

DE

CODIGO

COLORE

DE

CORES

CODIGO

CODICE

COLORE

C

O

D

S

E

0 Nero Preto Negro Musta Svart Sort Sort Schwarz Black Noir Zwart 0

1 Marrone Castanho Marrón Ruskea Brun Brun Brun Braun Brown Brun Bruin 1

2 Rosso Encar- Rojo Punainen Röd Rød Rød Rot Red Rouge Rood 2

3 Aran- Laranja Naran- Oranssi Orange Orange Orange Orange Orange Orange Oranje 3

4 Giallo Amarelo Amarillo Keltainen Gul Gul Gul Gelb Yellow Jaune Geel 4

5 Verde Verde Verde Vihreä Grön Grøn Grønn Grün Green Vert Groen 5

6 Blu Azul Azul Sininen Blå Blå Blå Blau Blue Blue Blauw 6

7 Viola Violeta Morado Purppura Lila Violet Violet Violet Purple Violet Paars 7

8 Grigio Cinzento Gris Harmaa Grå Grå Grå Grau Grey Gris Grijs 8

9 Bianco Branco Blanco Valkoinen Vit Hvid Hvidt Weiss White Blanc Wit 9

A Argento Prateado Plata Hopea Silver Sølv Sølv Silber Silver Argent Zilver A

B Oro Dourado Oro Kulta Guld Guld Guldl Gold Gold Or Goud B

5

Construction

CONSTRUCTION

The unit consists out of two PCB’s, one is the main PCB, P8021B and the other
is the left channel input section P8021L.
First we will start with the small P8021L, then we assemble the P8021B.

FTip: The pictures on the packaging can be

used as a guideline.
However, due to possible changes it is not
100% reliable.

1. Diodes (check the polarity)

D...

CATHODE

q D1: 1N4148
q D2: 1N4148
q D3: 1N4148
q D4: 1N4148
q D5: 1N4148
q D6: 1N4148

6

P8021L

2. Resistors (check the color code)

R...

q R1: 10K (1-0-3)
q R2: 10K (1-0-3)
q R3: 10K (1-0-3)
q R4: 10K (1-0-3)
q R5: 10K 1-0-3)
q R6: 10K (1-0-3)
q R7: 1K (1-0-2)
q R8: 330R (3-3-1)

Construction

3. Capacitors

C...

q C1: 220p (221)
q C2: 220p (221)
q C3: 220p (221)
q C4: 220p (221)
q C5: 220p (221)
q C6: 220p (221)

4- Reed relays (check the position

of the notch)

RY...

q RY1: VR05051AS or eq.
q RY2: VR05051AS or eq
q RY3: VR05051AS or eq
q RY4: VR05051AS or eq
q RY5: VR05051AS or eq
q RY6: VR05051AS or eq.

6. RCA connectors.
Mount them straight and
against the PCB

q SK1: MJ-523AG/B BLACK
q SK2: MJ-523AG/B BLACK
q SK3: MJ-523AG/B BLACK
q SK4: MJ-523AG/B BLACK
q SK5: MJ-523AG/B BLACK
q SK6: MJ-523AG/B BLACK

7. Pin connector. Mount it exactly
as indicated

5. transistors

q T1: BC557
q T2: BC557
q T3: BC557
q T4: BC557
q T5: BC557
q T6: BC557

q SK7: HDR20/26

7

Construction

P8021B Assembly

8

Construction

1. Jump wires

q J1... J25

2. Diodes (check the polarity)

D...

CATHODE

q D1: 1N4148
q D2: 1N4148
q D3: 1N4148
q D4: 1N4148
q D5: 1N4148
q D6: 1N4148
q D7: 1N4148
q D8: 1N4148
q D9: 1N4007
q D10: 1N4007
q D11: 1N4007
q D12: 1N4007
q D13: 1N4007
q D14: 1N4007
q D15: 1N4007
q D16: 1N4007

3. Zener diode (check the polarity)

ZD...

CATHODE

q ZD1: 20V / 0.6W

4. Resistors (check the color code)

R...

q R1: 10K (1-0-3)
q R2: 10K (1-0-3)
q R3: 10K (1-0-3)
q R4: 10K (1-0-3)
q R5: 10K (1-0-3)
q R6: 10K (1-0-3)
q R7: 10K (1-0-3)
q R8: 10K (1-0-3)
q R9: 47K (4-7-3)
q R10: 470R (4-7-1)
q R11: 620R/1% (6-2-0-0)
q R12: 33R (3-3-0)
q R13: 33R (3-3-0)
q R14: 390K/1% (3-9-0-3)
q R15: 33K/1% (3-3-0-2)
q R16: 1K (1-0-2)
q R17: 47K (4-7-3)
q R18: 470R (4-7-1)
q R19: 620R/1% (6-2-0-0)
q R20: 390K/1% (3-9-0-3)
q R21: 33K/1% (3-3-0-2)

9

Construction

q R22: 1K (1-0-2)
q R23: 560R/1% (5-6-0-0)
q R24: 1K8/1% (1-8-0-1)
q R25A or R25B: 1K5 (1-5-0-1) (*)
q R26: 1K5 (1-5-2)
q R27: 560R/1% (5-6-0-0)
q R28A or R28B: 1K5 (1-5-2) (*)

* The position of R25 and R28 de­pends on the supplied IC for IC2
and IC3:

Mount R25B and R28B if type
OPA134 is supplied.
Mount R25A and R28A. If types
OPA604 or TLE2071 are supplied.

q R29: 1K8/1% (1-8-0-1)
q R30: 1K5 (1-5-2)
q R31: 56R (5-6-0)
q R32: 56R (5-6-0)
q R33: 1K (1-0-2)
q R34: 330R (3-3-1)
q R35: 1R (1-0-0)
q R36: 1R (1-0-0)
q R37: 1R (1-0-0)
q R38: 1R (1-0-0)
q R39: 1K/1% (1-0-0-1)
q R40: 1K/1% (1-0-0-1)
q R41: 1K (1-0-2)
q R42: 1K (1-0-2)
q R43: 1K (1-0-2)
q R44: 1K (1-0-2)
q R45: 10K (1-0-3)
q R46: 10K (1-0-3)
q R47: 10K (1-0-3)
q R48: 10K (1-0-3)
q R49: 10K (1-0-3)
q R50: 4K7 (4-7-2)
q R51: 1R (1-0-0)
q R52: 470R (4-7-1)
q R53: 1K5 (1-5-2)

5. Choke

L...

q L1: 1uH (1-0)
q L2: 1uH (1-0)

6. IC sockets

q IC1: 8P
q IC2: 8P
q IC3: 8P
q IC4: 18P

7. Female header

SK..

J...

q SK7: 20P (type 96120205)

L...

10

Construction

8. Capacitors

q C1: 220p (221)
q C2: 220p (221)
q C3: 220p (221)
q C4: 220p (221)
q C5: 220p (221)
q C6: 220p (221)
q C7: 220p (221)
q C8: 220p (221)
q C9: 220p (221)
q C10: 2n2 (222, 2200)
q C11: 2n2 (222, 2200)
q C12: 8n2 (822, 8200)
q C13: 8n2 (822, 8200)
q C14: 100n (104, 0.1, u1)
q C15: 100n (104, 0.1, u1)
q C16: 100n (104, 0.1, u1)
q C17: 100n (104, 0.1, u1)
q C18: 100n (104, 0.1, u1)
q C19: 100n (104, 0.1, u1)
q C20: 100n (104, 0.1, u1)
q C21: 100n (104, 0.1, u1)
q C22: 100n (104, 0.1, u1)
q C23: 100n (104, 0.1, u1)
q C24: 100n (104, 0.1, u1)
q C25: 100n (104, 0.1, u1)
q C26: 100n (104, 0.1, u1)
q C27: 100n (104, 0.1, u1)
q C28: 100n (104, 0.1, u1)
q C29: 100n (104, 0.1, u1)
q C30: 2.2uF
q C31: 2.2uF

9. Reed relays (check the position

of the notch)

C...

RY...

q RY1: VR05051AS or eq.
q RY2: VR05051AS or eq
q RY3: VR05051AS or eq
q RY4: VR05051AS or eq
q RY5: VR05051AS or eq
q RY6: VR05051AS or eq.
q RY7: VR05051AS or eq.
q RY8: VR05051AS or eq.

10. Pin header connector, cut at
the indicated 5 pins

5

q SK8: 5P
q SK9: 5P

11

Construction

11. transistors

q T1: BC557
q T2: BC557
q T3: BC557
q T4: BC557
q T5: BC557
q T6: BC557
q T7: BC557
q T8: BC557

12. Trim potentiometer

13. Push button
Mount them straight against
the PCB surface !

q SW1: TS-04PV
q SW2: TS-04PV
q SW3: TS-04PV
q SW4: TS-04PV
q SW5: TS-04PV

Remark: The metal part of these but­tons are used as jump wire.
Be sure not to test or use the unit
without soldering these push buttons.

14. Phone jack.
Mount him straight against the
PCB surface !

q RV1: 100K
q RV2: 100K

12

SK..

J...

q SK13: JCF3.5 (3.5mm jack)

L'

R

R'

L

C...

Construction

15. RCA connectors.
Mount them straight and
against the PCB

q SK1: MJ-523AG/R RED
q SK2: MJ-523AG/R RED
q SK3: MJ-523AG/R RED
q SK4: MJ-523AG/R RED
q SK5: MJ-523AG/R RED
q SK6: MJ-523AG/R RED

16. Electrolytic capacitors.
Check the polarity !

q C32: 47µ
q C33: 47µ
q C34: 100µ
q C35: 100µ
q C36: 100µ
q C37: 470µ
q C38: 470µ
q C39: 470µ
q C40: 470µ
q C41: 470µ
q C42: 1000µ
q C43: 1000µ
q C44: 1000µ
q C45: 1000µ
q C46: 1000µ
q C47: 1000µ

17. Voltage regulator.
The back side corresponds to
the thick line.

VR...

q VR1 UA7815
q VR2 UA7915
q VR3 UA7805

18. Transformer.

TRANSFORMER

q TR1: TR8021, 9V-2x18V/ 6VA

13

Construction

19. Volume potentiometer.

q RV3: STRK27103 (2x50K ALPS)

CAUTION:
This is a high quality
potentiometer, handle it with care.
Follow the mounting instructions
exactly and in order!

1.Mount the support bracket onto the
potentiometer. Tighten the nut
carefully.

2.Mount the potentiometer onto the
PCB, using two 6mm (0.23”)
screws and M3 nut.

Only slightly tighten the nuts !
Do not solder the potentiometer

connections yet !

RV...

20. Mains voltage selection

Use a piece of isolated brown wire to
select the mains (outlet) voltage, as
indicated on the PC board.

q For 115Vac (100 to 120Vac)
A jumper between A-B, and a jumper
between C-D.

A B C D

q For 230Vac (220 to 240Vac)

A jumper between B-C.

B C

Using a black marker, erase the
not used voltage at the back of the
unit.

21. Mains voltage connection
preparation

14

q Connect a 10cm blue wire to the

point N of SK12.

q Connect a 10cm brown wire to the

point L of SK12.

q Connect a 10cm yellow/green

wire to the earth point of SK12.

Later these connection will be
soldered to the mains connector.

Construction

22. Mounting the LED’s. Check the polarity ! Short lead = Cathode or— !

LD...

CATHODE

First: Bend the leads exactly like the
drawing.

Next: Solder one lead, and check the
position, if necessary correct by heat­ing the soldering.

Last: Solder the second connection.

q LD7 L-424YDT

C

q LD1 L-424YDT
q LD2 L-424YDT
q LD3 L-424YDT
q LD4 L-424YDT
q LD5 L-424YDT
q LD6 L-424YDT

C

q LD8 L-424YDT

CAUTION:
After bending the
leads the long
appearing lead
will be the cath­ode!

IMPORTANT

Mount these LED’s exactly like in the
drawing, otherwise some LED’s will
not fit correctly in the front panel.
Please also use the front panel as a
positioning reference.

3mm

FIG. 1

3mm

12mm

FIG. 2

7mm

FIG. 3

15

Construction

23. Mounting the sub PCB support

q Mount four 2cm (0.8”)

M3 spacers at the indi­cated positions using
four 6mm (0.23”) M3
screws.

16

24. Enclosure preparation

q Cut the thread in

the holes for the
enclosure feet in
one of the alumi­num profiles, us­ing the supplied
special M4 screw
as a tap.

q Mount the Feet on the

aluminum profile, using
two M4 hexagonal Al­len screws. Use the
supplied Allen wrench.
It is advisable to stick
the protection adhe­sive onto the feet.

q Cut the thread in the

front and back of the
aluminum profiles, us­ing the supplied special
M4 screw (4 holes per
piece)

q Cut the thread in the back

panel phono ground screw
position, using the supplied
special M3 screw.

Enclosure preparation

FIG. 1

FIG. 2

FIG. 3

FIG. 4

17

Enclosure preparation

q Position the main PCB in the

aluminum profile that is pre­pared with the feet. The potenti­ometer must be at the same
side of the feet.

Align pcb with profile !

FIG. 5

q Mark the center position of the three fixation holes on the aluminum.

18

Enclosure preparation

0.000

q Remove the pcb and use

a knife or a screwdriver to
scratch the paint from the
aluminum fixation, from
the hole closest to the
back end. This fixation will
be used later to connect
the ground and earth.

q Mount the 3, 5mm

(0.14”) spacers like
in the drawing. Us­ing three hexago­nal screws and a
washer. Do not
tighten the spacers
yet.

q Position the PCB in the enclosure and check if the position of the spacers is

correct, if so, remove the PCB and tighten the spacers.

q Using an ohmmeter, measure between the edge of the aluminum profile and

the back spacer, if there is a good electric contact (0 ohm). If not, repeat the
above step to remove the paint under the spacer.

FIG. 6

5mm M3 spacer

FIG. 7

M3 hex. nut
Washer

FIG. 8

19

Final assembly

25. Potentiometer assembly and final PCB mount

q Mount the PCB into the enclosure like before.

q Fix the pcb using a 5mm

spacers next to C36.

q Mount the knob onto the potenti-

ometer. (check the notch position)

Play?

FIG. 1

Tip: Check if the

pcb does not have
to much play at the
potentiometer posi­tion.
If there is too much
play, put a piece of

tape round the edge of the pcb to remove
the slack.

FIG. 3

FIG. 2

MAX

FUse the supplied Allen wrench

20

MIN

Final assembly

q Now carefully mount the front panel,

using two M4 Allen screws. Check
the position of the LED’s.

q Check if the potentiometer turns

smoothly without touching the front
panel, otherwise correct his position
or the position of the front panel.

q Check if the phones connector (metal

part) does not touch the front panel.

FIG. 4

F Use the supplied Allen wrench

q Remove the front panel and fix the nuts of the potentiometer bracket.
q Remove the PCB from the enclosure and solder the potentiometer connec-

tions.

q Again mount the pcb into the enclosure.

q Fix the pcb using a 2cm

(0.8”) spacer at the position
next to SK7 and use 5mm
spacers to fix the other two
positions. Measure, using an
ohm meter (or continuity
beeper) if the 2cm spacer is
electrically connected to the
ground wire (yellow green
wire). If not, recheck if the
paint of the aluminum is cor­rectly removed.

q Mount the left channel PCB onto

the spacers, check that the con­nector is correctly inserted. Fix the
PCB using five 6mm M3 screws.

SPACER

FIG. 5

FIG. 6

21

Final assembly

26. Final assembly and connection

q Mount (insert) the mains

connector onto the rear
panel. Insert a 250mA
fuse into the connector
(there is also room for a
spare fuse).

q Mount the rear panel

onto the enclosure,
using two M4 Allen
screws.

q Mount the plastic phono ground screw onto the back panel.

q Connect the mains wires to

the mains connector, Blue=
Neutral, Brown= Live, and
green/yellow= Earth. Use a
piece of 1.5cm (0.6”) shrink
tube to isolate each con­nection.

q Mount the front panel onto

the front, using two M4 Al­len screws.

FIG. 1

FIG. 2

FCheck the position of the

LED’s and check if all but­tons are working correctly.

It could be that paint rest
over in the holes, is pre­venting the buttons from
smooth operation.

22

FIG. 3

Test and adjustment

27. Test and adjustment

Connect the mains AC voltage to the mains connector. Check if the power LED
(in the center of the PCB) is lit. This means that the +15V and –15V are correct.

CAUTION: Some points on the PCB are connected to the dangerous
mains voltage.

!

Disconnect the mains plug.
Now insert the IC’s into their sockets:

q IC1 NE5532
q IC2 TLE2071 / OPA134 / OPA604
q IC3 TLE2071 / OPA134 / OPA604
q IC4 VK8021 / PIC16C54RC

Offset adjustment:

It is important that the output of the amplifiers are free of DC voltage therefore
the offset voltage needs adjustment:

1. Connect the unit to the mains.

2. Push the CD input selector button, the corresponding LED should lit.

3. Push and hold the CD input selector button, the +6dB LED should lit.

4. Use a multimeter and set it to the lowest voltage range (2Vdc or lower).

5. Measure between GND (the metal bracket of the potentiometer can be used)
and J8 (Left channel offset adjustment).

6. Adjust the offset trimmer (next to IC2) until the meter indicates around 0V

7. Measure at point J9 (Right channel offset adjustment).

8. Adjust the offset trimmer (next to IC3) until the meter indicates around 0V

Check the user manual to test all functions and operation of the unit, then the
cover aluminum can be mounted.
Please note that the user manual is also used for the ready assembled version.
Some remarks may not be related to the kit version.

23

Diagram

SK1
PU/LINE

SK2

CD

SK3
TUNER

SK4

REC

SK5
MONITOR

SK6
LINE OUT R

C1
220p

C2
220p

C3
220p

C4
220p

220p

220p

R10

470R

620R/1%

20
19
18
17
16
15
14
13
12
11
10

9
8
7
6
5
4
3
2
1

Line out L

Input2
Input4
Mute

C31

2.2uF

+5V

+15V

R12
33R

C35

C14

100n

100µ

8 4

3

NE5532

2

IC1A

C34

C15

R13
33R

100µ

100n

-15V

Input1
Input3
Monitor

+5V

BC557

D8

T8

1N4148

R8
10K

Mount R28B for OPA134 else R28A

RV3B

50K

BC557

T7

D7

1N4148

R7
10K

1

R14

C13
8n2

R15

33K/1%

C10
2n2

C30

2.2uF
RV3A

50K

RY8

+6dB

TLE2071 / OPA134 / OPA604

RY7

+6dB

R30
1K5

R16

R19

390K/1%

1K

Mount R25B for OPA134 else R25A

C16

100n

R23
560R/1%

R39
1K/1%

Line out L

C18

R27
560R/1%

R40
1K/1%

L1

1uH

L2

1uH

SK9

620R/1%

C32

+15VL

3
2

3
2

47µ

R18
470R

IC2

-15VL

+15VR

IC3

-15VR

R20
390K/1%

7 4

7 4

220p

220p

5
6

C12

RV1

1

1

C7

C8

LINEPULINE

JP5

8n2

8 5

C17
100n

8 5

C19
100n

SK13

R17
47K

TLE2071 / OPA134 /OPA604

R24
1K8/1%

100n

R29
1K8/1%

R31

56R

R32

56R

PU

6

R26

1K5

R28A

6

1K5

NE5532

IC1B

R21
33K/1%

C11

100K

R25A

-15VR

RV2

100K

2n2

-15VL

1K5

R22
1K

7

+15VL

R25B

1K5

+15VL

1K5

R28B

JP5

RY1

D1

1N4148

RY2

D2

1N4148

RY3

D3

1N4148

RY4

D4

1N4148

RY5

C5

D5

1N4148

RY6

C6

D6

1N4148

PU

PU

Input1

Input2

Input3

Input4

Monitor

R9

47K

R11

C33

47µ

SK7

Mute

+5V

BC557

T1

R1
10K

+5V

BC557

T2

R2
10K

+5V

BC557

T3

R3
10K

+5V

BC557

T4

R4
10K

R33
1K

+5V

BC557

T5

R5
10K

R34
330R

+5V

BC557

T6

R6
10K

SK8

LINE

LINE

RIGHT INPUT / OUTPUT SECTION
AMPLIFIER SECTION

24

© Velleman Kit

Mains selection

Diagram

+15VL

-15VL

C39

R51
1R

+15VR

470µ

C38

470µ

-15VR

R37

R35

C41

1R

R36

1R

470µ

C40

470µ
R38

1R

1R

+5V

C43

C42

100µ

C36

C26

1000µ

C25

1000µ

+15V

-15V

C28

100n

100n

100n

LD8

R53
1K5

L-424YDT

VR3
UA7805

POWER SUPPLY SECTION

+5V

R42

L-424YDT

LD5

L-424YDT

R43
1K

LD6

1K

L-424YDT

Input1
Input2
Input3
Input4
+6dB
Mute

Monitor

LD1

L-424YDT

LD2

L-424YDT

LD3

R44
1K

L-424YDT

LD4

UA7815

IO

VR1

ZD1
ZA20V

UA7915

GND

R41
1K

GND

GND

IO

IO

VR2

100n

C23

100n

100n

C24

C27

C47

C44

1000µ

1000µ

C45

1000µ

C46

1000µ

C37

470µ

D9

D10

D11

D12

D13

D14

1N4007

1N4007

1N4007

1N4007

1N4007

1N4007

+5V

D15

D16

1N4007

C22

C21

1N4007

100n

100n

C29

100n

10

18

9

0

8
7

9

6

0

TR8021

SK14

R50
4K7

C9

LD7

L-424YDT

220p

+5V SW4

IC4

16

OSC1/CLKIN

3

T0CKI

4

MCLR/VPP

2

RA3

6

RB0

7

RB1

8

RB2

11

RB5

PIC16C54RC

C20

VDD

14

OSC2/CLKOUT

VSS

5

100n

RA1
RA0
RB7
RB6
RB3
RB4
RA2

R49

R48

10K

10K

15
18
17
13
12
9
10
1

R45

10K

R46

R47

10K

TR1

115

115

R52

470R

FASTON
To Cover

10K

1

0

2

0418

5

L

MAINS

230V
B+C

SW3

TUNER
SW2

SW1

PU/LINE
SW5

STBY / MUTE

REC

CD

SK10

N

115V
A+B

C+D

A
B

C
D

SK11

SK12

CONTROLLER SECTION

© Velleman Kit

25

Diagram

PU/LINE

SK1

CD

SK2

TUNER

SK3

REC

SK4

MONITOR

SK5

LINE OUT L

SK6

C1
220p

C2
220p

C3
220p

C4
220p

C5

220p

C6

220p

RY1

RY2

RY3

RY4

RY5

D1

1N4148

D2

1N4148

D3

1N4148

D4

1N4148

D5

1N4148

RY6

D6

1N4148

+5V

BC557

T1

R1
10K

+5V

BC557

T2

R2
10K

+5V

BC557

T3

R3
10K

+5V

BC557

T4

R4
10K

R7
1K

+5V

BC557

T5

R5
10K

R8
330R

+5V

BC557

T6

R6
10K

SK7

20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1

+5V

LEFT INPUT SECTION

26

© Velleman Kit

NOTES:

Notes

27

VELLEMAN KIT NV

Legen Heirweg 33

9890 Gavere

Belgium Europe

Info ?: http://www.velleman.be

Questions ?: [e-mail]

Modifications and typographical errors reserved
© Velleman Kit nv
H8021IP - 2000 - ED1