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CowBell:

You will notice that all the names of components have a star to match the names on the original TR-808 schematic. The TR-808 have two different circuits for instruments (Main board and Voice board). As we have design a single circuit, we had components with same names due to the addition of the star. All components with a star in their name are the components of the TR-808 Voice board . Prepare all these components before beginning assembly. List of components:

Image

Description

Part

Value

Qty

Polyester capacitor (2A103J)

C28*

10n

1

Polyester capacitor (2A223J)

C76*

22n

1

Polyester capacitor (2A332J)

C29*

3.3n

1

Polyester capacitor (2A222J)

C30*, C31*

2.2n

2

Electrolytic capacitor

C32*, C33*

10/25

2

Electrolytic capacitor

C9*

0.47/50

1

Electrolytic capacitor

C34*, C75*

 

 

1/50

2

Diode

D1*, D2*, D3*, D4*

1N4148

4

NPN Silicon Transistor

Q1*, Q14*, Q15*

2SC945

3

PNP Silicon Transistor

Q5*

2SA733

1

1/4w carbon resistor

R4*, R9*, R117*

22K

3

1/4w carbon resistor

R5*, R26*, R27*

10K

3

1/4w carbon resistor

R14*

4K7

1

1/4w carbon resistor

R18*, R21*, R22*

3K3

3

1/4w carbon resistor

R19*, R28*, R29*, R23*

100K

4

1/4w carbon resistor

R20*

15K

1

1/4w carbon resistor

R24*, R63*, R65*

2K2

3

1/4w carbon resistor

R25*, R30*, R32*

470K

3

1/4w carbon resistor

R31*, R33*

100R

2

1/4w carbon resistor

R62*, R64*, R82*

33K

3

1/4w carbon resistor

R116*

8K2

1

1/4w carbon resistor

R122*, R163*

1K

2

Dual Operational Amplifier

U2, U6

µPC4558C

2

Potentiometer (A502)

VR5*

5KA

1

 

Make it:


Here is the Cowbell.

Solder all resistors.

Solder each value one after the other.

Solder the four diodes 1N4148

MAKE SURE DIODES ARE IN THE RIGHT WAY

Solder polyesters capacitors



Solder electrolytics capacitors

MAKE SURE ELECTROLYTICS CAPACITORS ARE IN THE RIGHT WAY

 

Solder transistors.Do not get confused between 2SA733 and 2SC945  it is not the same transistors.

 

MAKE SURE TRANSISTORS ARE IN THE RIGHT WAY

 

Connect the power transformer. Test  4558 power supply before solder. The green dot is-15V, the red dot is +15 V (plus or minus 5%). You have the ground on the potentiometer big square pad . Always check that the four wires from the power supply is well connected.

 

THEN DONT FORGET TO DISCONNECT THE POWER TRANSFORMER. DO NOT SOLDER COMPONENT AS THE CIRCUIT IS POWERED !

Finally return the PCB and solder the potentiometer on the  opposite side of components.

 

You can then go to Cymball assembly