Velleman K4102 User manual

K4102
ILLUSTRATED ASSEMBLY MANUAL H4102IP-1
Total solder points: 79
Difficulty level: beginner 1 2 3 4 5 advanced
Practicetheguitarwithoutdisturbing
others.
GUITAR PREAMPLIFIER WITH HEADPHONE OUTPUT

2
Features:
An electric guitar cannot be connected to just any amplifier or audio installation. This preamplifier has been
designed for this purpose and provides you with a headphone output, allowing you to practice without
disturbing others. Moreover, it is fitted with a special device for tone adjustment, allowing anyone to create
their personal sound.
 sound adjustment
 adjustable input sensitivity
 low noise
 housing included
Specifications:
 Headphones output: max. 2 x 50mW / 32ohm
 Power supply: 9V battery (not incl.)
 Dimensions: 70 x 30 x 105mm (2.8" x 1.2" x 4.1")
Features & Specifications

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 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 drawings.
⇒Values on the circuit diagram are subject to changes.
⇒Values in this assembly guide are correct*
⇒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.
0.000

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Assembly hints
1.3 Soldering Hints :
1- Mount the component against the PCB surface 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 !
DO NOT BLINDLY FOLLOW THE ORDER OF THE
COMPONENTS ONTO THE TAPE. ALWAYS CHECK
THEIR VALUE ON THE PARTS LIST!

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Construction
 R1 : 470K (4 - 7 - 4 - B)
 R2 : 470K (4 - 7 - 4 - B)
 R3 : 47K (4 - 7 - 3 - B)
 R4 : 10K (1 - 0 - 3 - B)
 R5 : 10K (1 - 0 - 3 - B)
 R6 : 10K (1 - 0 - 3 - B)
 R7 : 68 (6 - 8 - 0 - B)
 R8 : 68 (6 - 8 - 0 - B)
 R9 : 390 (3 - 9 - 1 - B)
 R10 : 2,2 (2 - 2 - B - B)
 R11 : 2,2 (2 - 2 - B - B)
2. 1/4W Resistors
R...
 ZD1 : 4V7
1. Zenerdiode. Watch the
polarity!
ZD...
CATHODE
 C1 : 470pF (471)
 C2 : 10nF (103)
 C3 : 33nF (333)
 C4 : 33nF (333)
 C5 : 100nF (104)
 C6 : 100nF (104)
 C7 : 470nF (474)
 C8 : 470nF (474)
 C9 : 470nF (474)
3. Capacitors
 IC1 : 8p
4. IC socket. Watch the
position of the notch!
 RV1 : 100K
 RV2 : 1K
5. Resistor trimmers
 SW1
6. Switch
SW.. .
 C10 : 220µF
 C11 : 220µF
 C12 : 220µF
Watch the polarity!
7. Electrolytic Capacitors
C...

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Construction
 J1 GUITAR IN
 J2 LINE OUT
8. RCA connectors
...
 J3 : 3,5mm stereo phone
9. Headphones connector
J...
L'
R
R'
L
10. LED
LD...
CA TH ODE
23mm
0.9"
18mm
 LD1 : 3mm red
 IC1 : NE5532A
11. IC. Watch the position of
the notch!
The connection leads are first
plaited through the openings to
reduce pulling. The red is
connected to the "+" and the
black to the "-".
12. Battery snap
E...
BLACK
RED
Fig 1.0

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Assembly in the housing
13. Assembly in the housing
 Attach the sticker showing the connections to the housing, fig 4.0.
 Mount three spacers to the bottom of the housing, together with a shakeproof washer and an M3
countersunk bolt, see figure 2.0
 Mount the PCB on the spacers using the three M3 bolts
 Click the shaft into the tone-control potentiometer and mount the knob on the shaft, fig 3.0
 After connection of the 9V battery (check the polarity), the cover of the housing can be
clicked in place.
HOUSING
6mm M3 BOLT
PCB
LOCK WASHER
8mm M3 SPACER
4mm M3 BOLT
Fig 2.0
Fig 3.0

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Assembly in the housing
Tone control
Power led
Level adjustment
Power on/off
Headphones
Output
Guitar IN
Fig 4.0
Sticker

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 Connect a 9V battery and switch the equipment on. The LED should normally light up. This LED is also used as a
"battery low" indication.
 Turn potentiometer RV1 to the middle of its adjustment range and connect a pair of headphones to the unit. A slight
hum should be heard in the headphones when the central terminal of the input connector is touched. Turn the tone
control RV2 clockwise and slight noise should be heard.
 The guitar can be connected to the input connector by using a suitable cable. The sensitivity can be controlled using
"RV1".
 The output connector can be connected to the "TAPE IN" or "AUX" input of a stereo system. Be very careful with
the volume knob so that you do not damage your expensive speakers.
14. Test & use
Test & use

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15. Schematic diagram.
Schematic diagram
3
4
8
2
1
7
6
5
R-HEADPHONE
GND
L-HEADPHONE
R5
J3
C8
R10
C10
J3
J2
R6
R8
C9
R11
C11
C2
TONE
R7
R4
C7
R3
A1
R2
C3
RV1
C5
R1
ZD1
LD1
R9
A2
C6
C12
SW1
+9V
C1
LEVEL.ADJ
RV2
BATTERY
GND
GUITAR.IN
J1
GND
LINE.OUT
GND
CONTROL
C4

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PCB
16. PCB

5 410329 289188
Modifications and typographical errors reserved
© Velleman nv.
H4102IP - 2004 - ED1 (rev.1.0)
VELLEMAN NV
Legen Heirweg 33, 9890 Gavere
Belgium - Europe