Velleman K8021 User manual

Total solder points: 500
Difficulty level:
beginner 1o2o3o4o5þadvanced
K8021
HIGH-END CONTROL AMPLIFIER
ILLUSTRATED ASSEMBLY MANUAL H8021IP-1

VELLEMAN KIT NV
Legen Heirweg 33
9890 Gavere
Belgium
http://www.velleman.be

3
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

4
⇒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 !

5
Color code table
IPESF SDK NDGB FNL C O D E
CODICE
COLORE CODIGO
DE
CORES
CODIGO
DE
COLORE
S
VÄRI
KOODI FÄRG
SCHEMA FARVE-
KODE FARGE-
KODE FARB
KODE COLOUR
CODE CODIFI-
CATION DES COU-
KLEUR
KODE C
O D E
0Nero Preto Negro Musta Svart Sort Sort Schwarz Black Noir Zwart 0 1Marrone Castanho Marrón Ruskea Brun Brun Brun Braun Brown Brun Bruin 1 2Rosso Encar- Rojo Punainen Röd Rød Rød Rot Red Rouge Rood 2 3Aran- Laranja Naran- Oranssi Orange Orange Orange Orange Orange Orange Oranje 3 4Giallo Amarelo Amarillo Keltainen Gul Gul Gul Gelb Yellow Jaune Geel 4 5Verde Verde Verde Vihreä Grön Grøn Grønn Grün Green Vert Groen 5 6Blu Azul Azul Sininen Blå Blå Blå Blau Blue Blue Blauw 6 7Viola Violeta Morado Purppura Lila Violet Violet Violet Purple Violet Paars 7 8Grigio Cinzento Gris Harmaa Grå Grå Grå Grau Grey Gris Grijs 8 9Bianco Branco Blanco Valkoinen Vit Hvid Hvidt Weiss White Blanc Wit 9 AArgento Prateado Plata Hopea Silver Sølv Sølv Silber Silver Argent Zilver A BOro Dourado Oro Kulta Guld Guld Guldl Gold Gold Or Goud B
5%
4K7= ( 4 - 7 - 2 - B )
1%
4K7= ( 4 - 7 - 0 - 1 - 1 )
COLOR= 2… 5

6
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.
CONSTRUCTION
qD1: 1N4148
qD2: 1N4148
qD3: 1N4148
qD4: 1N4148
qD5: 1N4148
qD6: 1N4148
1. Diodes (check the polarity)
CATHODE
D...
qR1: 10K (1-0-3)
qR2: 10K (1-0-3)
qR3: 10K (1-0-3)
qR4: 10K (1-0-3)
qR5: 10K 1-0-3)
qR6: 10K (1-0-3)
qR7: 1K (1-0-2)
qR8: 330R (3-3-1)
2. Resistors (check the color code)
R...
Construction
P8021L

7
qT1: BC557
qT2: BC557
qT3: BC557
qT4: BC557
qT5: BC557
qT6: BC557
5. transistors
qC1: 220p (221)
qC2: 220p (221)
qC3: 220p (221)
qC4: 220p (221)
qC5: 220p (221)
qC6: 220p (221)
3. Capacitors
C...
Construction
qRY1: VR05051AS or eq.
qRY2: VR05051AS or eq
qRY3: VR05051AS or eq
qRY4: VR05051AS or eq
qRY5: VR05051AS or eq
qRY6: VR05051AS or eq.
4-Reed relays (check the position
of the notch)
qSK1: MJ-523AG/B BLACK
qSK2: MJ-523AG/B BLACK
qSK3: MJ-523AG/B BLACK
qSK4: MJ-523AG/B BLACK
qSK5: MJ-523AG/B BLACK
qSK6: MJ-523AG/B BLACK
6. RCA connectors.
Mount them straight and
against the PCB
qSK7: HDR20/26
7. Pin connector. Mount it exactly
as indicated
RY...

8
P8021B Assembly
Construction

9
qJ1... J25
1. Jump wires
qR1: 10K (1-0-3)
qR2: 10K (1-0-3)
qR3: 10K (1-0-3)
qR4: 10K (1-0-3)
qR5: 10K (1-0-3)
qR6: 10K (1-0-3)
qR7: 10K (1-0-3)
qR8: 10K (1-0-3)
qR9: 47K (4-7-3)
qR10: 470R (4-7-1)
qR11: 620R/1% (6-2-0-0)
qR12: 33R (3-3-0)
qR13: 33R (3-3-0)
qR14: 390K/1% (3-9-0-3)
qR15: 33K/1% (3-3-0-2)
qR16: 1K (1-0-2)
qR17: 47K (4-7-3)
qR18: 470R (4-7-1)
qR19: 620R/1% (6-2-0-0)
qR20: 390K/1% (3-9-0-3)
qR21: 33K/1% (3-3-0-2)
4. Resistors (check the color code)
qD1: 1N4148
qD2: 1N4148
qD3: 1N4148
qD4: 1N4148
qD5: 1N4148
qD6: 1N4148
qD7: 1N4148
qD8: 1N4148
qD9: 1N4007
qD10: 1N4007
qD11: 1N4007
qD12: 1N4007
qD13: 1N4007
qD14: 1N4007
qD15: 1N4007
qD16: 1N4007
2. Diodes (check the polarity)
CATHODE
D... R...
qZD1: 20V / 0.6W
3. Zener diode (check the polarity)
CATHODE
ZD...
Construction

10
qR22: 1K (1-0-2)
qR23: 560R/1% (5-6-0-0)
qR24: 1K8/1% (1-8-0-1)
qR25A or R25B: 1K5 (1-5-0-1) (*)
qR26: 1K5 (1-5-2)
qR27: 560R/1% (5-6-0-0)
qR28A or R28B: 1K5 (1-5-2) (*)
* The position of R25 and R28 de-
pends 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.
qR29: 1K8/1% (1-8-0-1)
qR30: 1K5 (1-5-2)
qR31: 56R (5-6-0)
qR32: 56R (5-6-0)
qR33: 1K (1-0-2)
qR34: 330R (3-3-1)
qR35: 1R (1-0-0)
qR36: 1R (1-0-0)
qR37: 1R (1-0-0)
qR38: 1R (1-0-0)
qR39: 1K/1% (1-0-0-1)
qR40: 1K/1% (1-0-0-1)
qR41: 1K (1-0-2)
qR42: 1K (1-0-2)
qR43: 1K (1-0-2)
qR44: 1K (1-0-2)
qR45: 10K (1-0-3)
qR46: 10K (1-0-3)
qR47: 10K (1-0-3)
qR48: 10K (1-0-3)
qR49: 10K (1-0-3)
qR50: 4K7 (4-7-2)
qR51: 1R (1-0-0)
qR52: 470R (4-7-1)
qR53: 1K5 (1-5-2)
qL1: 1uH (1-0)
qL2: 1uH (1-0)
5. Choke
L...
L...
qIC1: 8P
qIC2: 8P
qIC3: 8P
qIC4: 18P
6. IC sockets
qSK7: 20P (type 96120205)
7. Female header
J...
SK..
Construction

11
qRY1: VR05051AS or eq.
qRY2: VR05051AS or eq
qRY3: VR05051AS or eq
qRY4: VR05051AS or eq
qRY5: VR05051AS or eq
qRY6: VR05051AS or eq.
qRY7: VR05051AS or eq.
qRY8: VR05051AS or eq.
9. Reed relays (check the position
of the notch)
qC1: 220p (221)
qC2: 220p (221)
qC3: 220p (221)
qC4: 220p (221)
qC5: 220p (221)
qC6: 220p (221)
qC7: 220p (221)
qC8: 220p (221)
qC9: 220p (221)
qC10: 2n2 (222, 2200)
qC11: 2n2 (222, 2200)
qC12: 8n2 (822, 8200)
qC13: 8n2 (822, 8200)
qC14: 100n (104, 0.1, u1)
qC15: 100n (104, 0.1, u1)
qC16: 100n (104, 0.1, u1)
qC17: 100n (104, 0.1, u1)
qC18: 100n (104, 0.1, u1)
qC19: 100n (104, 0.1, u1)
qC20: 100n (104, 0.1, u1)
qC21: 100n (104, 0.1, u1)
qC22: 100n (104, 0.1, u1)
qC23: 100n (104, 0.1, u1)
qC24: 100n (104, 0.1, u1)
qC25: 100n (104, 0.1, u1)
qC26: 100n (104, 0.1, u1)
qC27: 100n (104, 0.1, u1)
qC28: 100n (104, 0.1, u1)
qC29: 100n (104, 0.1, u1)
qC30: 2.2uF
qC31: 2.2uF
8. Capacitors
C...
qSK8: 5P
qSK9: 5P
10. Pin header connector, cut at
the indicated 5 pins
RY...
5
Construction

12
qRV1: 100K
qRV2: 100K
12. Trim potentiometer
qT1: BC557
qT2: BC557
qT3: BC557
qT4: BC557
qT5: BC557
qT6: BC557
qT7: BC557
qT8: BC557
11. transistors
qSK13: JCF3.5 (3.5mm jack)
14. Phone jack.
Mount him straight against the
PCB surface !
J...
L'
RR'
L
qSW1: TS-04PV
qSW2: TS-04PV
qSW3: TS-04PV
qSW4: TS-04PV
qSW5: TS-04PV
Remark: The metal part of these but-
tons are used as jump wire.
Be sure not to test or use the unit
without soldering these push buttons.
13. Push button
Mount them straight against
the PCB surface !
SK..
Construction

13
qSK1: MJ-523AG/R RED
qSK2: MJ-523AG/R RED
qSK3: MJ-523AG/R RED
qSK4: MJ-523AG/R RED
qSK5: MJ-523AG/R RED
qSK6: MJ-523AG/R RED
15. RCA connectors.
Mount them straight and
against the PCB
qC32: 47µ
qC33: 47µ
qC34: 100µ
qC35: 100µ
qC36: 100µ
qC37: 470µ
qC38: 470µ
qC39: 470µ
qC40: 470µ
qC41: 470µ
qC42: 1000µ
qC43: 1000µ
qC44: 1000µ
qC45: 1000µ
qC46: 1000µ
qC47: 1000µ
16. Electrolytic capacitors.
Check the polarity !
qVR1 UA7815
qVR2 UA7915
qVR3 UA7805
17. Voltage regulator.
The back side corresponds to
the thick line.
C...
VR...
qTR1: TR8021, 9V-2x18V/ 6VA
18. Transformer.
TRANSFORMER
Construction

14
qRV3: 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 !
19. Volume potentiometer.
Use a piece of isolated brown wire to
select the mains (outlet) voltage, as
indicated on the PC board.
qFor 115Vac (100 to 120Vac)
A jumper between A-B, and a jumper
between C-D.
qFor 230Vac (220 to 240Vac)
A jumper between B-C.
Using a black marker, erase the
not used voltage at the back of the
unit.
20. Mains voltage selection
qConnect a 10cm blue wire to the
point Nof SK12.
qConnect a 10cm brown wire to the
point Lof SK12.
qConnect a 10cm yellow/green
wire to the earth point of SK12.
Later these connection will be
soldered to the mains connector.
21. Mains voltage connection
preparation
RV...
Construction
A B C D
B C

15
First: Bend the leads exactly like the
drawing.
Next: Solder one lead, and check the
position, if necessary correct by heat-
ing the soldering.
Last: Solder the second connection.
qLD7 L-424YDT
qLD1 L-424YDT
qLD2 L-424YDT
qLD3 L-424YDT
qLD4 L-424YDT
qLD5 L-424YDT
qLD6 L-424YDT
qLD8 L-424YDT
22. Mounting the LED’s. Check the polarity ! Short lead = Cathode or—!
Construction
7mm
C
12mm
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
3mm
C
CATHODE
LD...
FIG. 1
FIG. 2
FIG. 3
CAUTION:
After bending the
leads the long
appearing lead
will be the cath-
ode!

16
qMount four 2cm (0.8”)
M3 spacers at the indi-
cated positions using
four 6mm (0.23”) M3
screws.
23. Mounting the sub PCB support
Construction

17
qCut the thread in
the holes for the
enclosure feet in
one of the alumi-
num profiles, us-
ing the supplied
special M4 screw
as a tap.
qMount the Feet on the
aluminum profile, using
two M4 hexagonal Al-
len screws. Use the
supplied Allen wrench.
It is advisable to stick
the protection adhe-
sive onto the feet.
qCut the thread in the
front and back of the
aluminum profiles, us-
ing the supplied special
M4 screw (4 holes per
piece)
qCut the thread in the back
panel phono ground screw
position, using the supplied
special M3 screw.
24. Enclosure preparation
Enclosure preparation
FIG. 1
FIG. 2
FIG. 3
FIG. 4

18
qPosition the main PCB in the
aluminum profile that is pre-
pared with the feet. The potenti-
ometer must be at the same
side of the feet.
qMark the center position of the three fixation holes on the aluminum.
Align pcb with profile !
Enclosure preparation
FIG. 5

19
qRemove 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.
qMount the 3, 5mm
(0.14”) spacers like
in the drawing. Us-
ing three hexago-
nal screws and a
washer. Do not
tighten the spacers
yet.
qPosition the PCB in the enclosure and check if the position of the spacers is
correct, if so, remove the PCB and tighten the spacers.
qUsing 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.
Enclosure preparation
FIG. 6
M3 hex. nut
5mm M3 spacer Washer
FIG. 7
0.000
FIG. 8

20
Final assembly
qMount the PCB into the enclosure like before.
qFix the pcb using a 5mm
spacers next to C36.
qMount the knob onto the potenti-
ometer. (check the notch position)
FUse the supplied Allen wrench
Tip: Check if the
pcb does not have
to much play at the
potentiometer posi-
tion.
If there is too much
play, put a piece of
tape round the edge of the pcb to remove
the slack.
Play?
MAX
MIN
25. Potentiometer assembly and final PCB mount
FIG. 1
FIG. 2
FIG. 3