Audio Amplifier Using TDA2030A

This is small power (about 14~18Watt) audio amplifier utilizing TDA2030 chip IC which is now obsolete.

The TDA2030 was manufactured by STMicroelectronics that is joint electronic company between France and Italia.

But analog audio device production had been stopped and this audio chip is no longer available.

Meanwhile somehow I still have four TDA2030 ICs (maybe I bought these chips about 10 years ago and simply forgot to use) in my parts inventory.

Although you can’t buy TDA2030 any more, a general audio amplifier making method explain in this instructable can be still helpful to make other amplifier which using still available audio IC chip such as LM1875.

I’ll introduce other audio amplifier DIY project using LM1875 in another instructable later.

Let’s start story about making small power amplifier which can be used as PC speaker.

Practically operational amplifier schematics can be found in the technical document of STMicroelectronics.

Or other useful amplifier circuit diagrams are quite abundant in Internet as TDA2030 was used to very popular audio IC chip for amplifier DIY before.

For example, the following web page shows diverse and detail instructions for making amplifier with the TDA2030 chip.

https://www.eleccircuit.com/tda2030-audio-amplifie...

By referring some information from Internet and STMicroelectronics documents, I’m re-drawing new amplifier schematics as shown in the picture above.

The followings are slight modifications from original schematics recommended by STMicroelectronics.

- Add-on 50K potentiometer (When output power of your music player such as PC’s audio output is relatively weak, use 20K pot for better volume control) for input audio volume control

- Using 1uF 100V (C1 in the schematics above) film capacitor as audio input coupling purpose

- Applying 220uF power filtering capacitor (C3 and C5) instead of 100uF electrolytic capacitor which is recommended by STMicroelectronics

- Adding 0.1uF ceramic capacitors (C8 and C9) for filtering high frequency noise from input power supply lines

- 4700uF of DC output smoothening electrolytic capacitors (C10 and C11) using instead of 2200uF cap recommended by STMicroelectronics

- Including 2 power indicator LEDs (D3 and D4) as well as 2 current limiting 1K resistors (R5 and R6)

Above modifications are not much critical and just included as personal preferences such as having visual LED power indicator, and anticipations for preventing high frequency noise from power supply lines by using additional 0.1uF ceramic capacitors and so on.

For example, originally recommended 100uF (C3 and C5) and 2200uF (C10 and C11) capacitors are quite OK for proper audio amplifying operation by TDA2030.

But using more high capacity of parts (such as 220uF and 4700uF) seems to make audio output quality more dynamic. (Maybe it can be personal impression. I can’t say any scientific backgrounds or proofs on this matter)

Therefore, several modifications mention above can be safely omitted when you want to make overall amplifier circuit simple.

Maybe it can be called as plastic enclosure, simply as acrylic box, or acrylic board chassis.

Let’s call it simply as chassis from now on in this story.

What shown above is one of chassis design example for housing audio amplifier circuits shall be made later.

I’m using different shape of chassis design for the TDA2030 amplifier in this story.

Anyway designing and assembling chassis is very important as quality level of finished amplifier product is highly dependable to the perfection of chassis design and relevant workmanships while assembling.

For making acrylic chassis shown in the picture above, the following materials are used.

- Acrylic boards (Top/Bottom 150mm (H) x 200mm (W) x 5mm (D) 2 boards, front/rear 60mm (H) x 250mm (W) x 3mm (D) 2 boards)

- “L” shape acrylic board mounting and fixing metal brackets

- M3 (2.5mm diameter size) bolts and nuts for fixing “L” shape bracket

- M4 (3mm diameter size) metal PCB supporter (total 63mm length) x 4

- M4 size nuts for fixing metal supporter

Then let’s look more detail about how chassis materials are prepared and assembled together in the step next.

All chassis materials introduced in the step 2 are assembled together as shown in the picture above.

The detail assembling methods are like follows.

- Front and rear acrylic boards are mounted on the bottom side panel with “L” shaped mounting brackets and M3 bolts and nuts

- Heat sink also mounted and fixed on the bottom side acrylic board with “L” shaped mounting brackets and M3 bolts and nuts

- Bottom side board mounting to the top side acrylic board with M4 size metal supporter, bolts and nuts

When assembling is finished, completed acrylic chassis is very sturdy and strong to stand several tens KG of heavy things can be safely stacked on the top of the chassis.

Also all electronic/electric circuit boards and components can be safely housed inside chassis and preventing any accidental touching by user.

When chassis assembling is completed, electric components should be mounted and wired together inside the acrylic chassis as shown in the picture above.

Detail about the relevant tasks is like below.

- Mounting power socket at the rear side acrylic panel (In my country household power voltage is 220V)

- Wiring 220V 2A fuses between power socket and transformer

- Connecting 220V 10A SPST (Single Pole Single Throw) power switch to the one side of home power line (Usually hot line side)

- Wiring transformer output (AC 15V lines) cables to the power supply circuit

Usually fuse should be connected to the hot side wire of wall-outlet.

Connecting fuse to neutral line is not conventional and quite rare.

But in very old house like mine, I can’t sure which wall-outlet socket terminal is hot or neutral as electric wiring had been done quite long time ago. (Maybe 30 more years ago….)

Therefore, simply two fuses are used between power socket and transformer for ensuring maximum safety!!.

Also I didn’t wiring ground wire of wall-outlet as I’m using totally insulated chassis made of Acrylic boards!

When you are using metallic chassis, you should grounding chassis to ground terminal of household power line. (This is must to-do when you using metallic chassis for ensuring safety and preventing any electrical shocks)

As any live and hot electric parts are exposed from my acrylic board chassis, I’m simply ignoring grounding wire in this DIY project.

This is snapshot for connecting power socket, switch and transformer.

Firstly I’m trying to use toroidal transformer as shown in the picture above.

But finally I changed the toroidal one to the somewhat specially made flat EI transformer having two 15V output terminals.

The electronic shop clerk who selling the EI transformer said voltage regulation quality is almost similar with the torodial transformer.

Therefore, a little bit special EI transformer is used for building TDA2030 amplifier in this DIY project.

As basic electrical wiring is completed, let’s move on to make power supply circuit PCB.

For wiring 220V flowing cables and circuits, you should use cable which conforming physical and electrical specifications of household 220V cabling standards.

Relatively simple split power supply circuit (+15V/-15V) is used for powering amplifier circuit.

As I mentioned at previous step, the 4700uF electrolytic capacitor is used for DC power smoothening purpose.

Usually 1000uF capacity is required for supplying about 1A current to the amplifier circuit.

Therefore, 2200uF capacitor is quite OK when operating TDA2030 chip at maximum level. (About 2A is electrical maximum of this chip)

The following parts are utilized for making power supply circuit.

- 30VA flattened EI transformer (220V input, 15V x 2 output)

- 30A silicon diode bridge rectifier x 1

- 4700uF electrolytic capacitor x 2 for DC power smoothening purpose

- 0.1uF 63V ceramic capacitor x 2 for high frequency noise bypassing

- 2 LED (RED x 1, GREEN x 1) for power supply visual indicator

- 1K resistor x 2 for LED current limiting

When AC 15V is supplied to this circuit, +/- 17.5V DC power can be supplied when amplifier load is not applied.

As an electrical specification of TDA2030 is like below, the power supply circuit designed above can supply adequate current while operating amplifier at any audio levels

- Supply voltage: maximum +/-18V (36V)

- Minimum voltage: +/-6 (12V)

- Output power: 4ohm typical 14W, 8ohm typical 9W

As power supply circuit is ready to use, let’s make amplifier circuit as the next step.

Firstly, TDA2030 chip should be prepared to be connected to the amplifier circuit.

As shown in the picture above, TDA2030 mounted on the heat-sink.

Insulation pad is attached between audio chip and heat-sink for preventing metal tab of TDA2030 (-V voltage) is not directly touching heat-sink.

Therefore, no voltage positional can be created on the exposed metal heat-sink.

All leads of TDA2030 are tightly sealed by thermal contraction tube and completely insulted from the metal heat-sink behind.

The five TDA2030 leads are categorized as two groups to be connected with amplifier circuit.

- Group 1: Pin 3 (-V power supply), Pin 5 (+V power supply)

- Group 2: Pin 1 (Non-inverting audio input), Pin 4 (Audio out), Pin 2 (Inverting audio input)

You will see later why TDA2030 leads are categorized as two parts.

As every sub-components of amplifier is ready, let’s make amplifier circuit in the next step.

Overall amplifier circuit is divided into two parts such as power supply PCB board and remaining audio signal processing PCB board.

According to the STMicroelectronics documentation, supply voltage bypassing capacitors should be located very near to TDA2030 chip to prevent possible oscillation.

Therefore, two 220uF electrolytic and 0.1uF film capacitors are soldered on small PCB board and located right next to the TDA2030 chip which is mounted and fixed on the heat-sink.

The following components are soldered on the small power supply PCB board.

- 220uF electrolytic capacitor immediately supplying current when transistors inside TDA2030 chip start audio signal amplification (Also it bypassing low frequency noise to grounding line)

- 0.1uF film capacitor bypassing high frequency noise to grounding line

As you can see in the wiring diagram above, the Group 1 leads (Pin 3 and Pin 5) of TDA2030 is connected to power supply PCB board.

I saw several comments from Internet contents that using relatively high capacity of bypassing electrolytic capacitor can improve audio signal amplification more dynamically.

Therefore, I’m using 220uF capacitor instead of 100uF capacitor recommended by STMicroelectronics.

Audio signal processing PCB board is including main amplifier circuit components as follows.

- 1uF 100V file capacitor is used for de-coupling such as blocking DC voltage and only passing AC audio signal

- Two 24K resistors are deciding amplification rate of TDA2030

- 680ohm and 22uF electrolytic capacitor stabilizing audio input signal

- Two 1N4001 silicon diode protecting TDA2030 from any voltage spikes which can damage the audio chip

- 1ohm and 0.18uF film capacitor forming Zobel network which stabilizing audio output frequency

The TDA2030 lead Group 2 (Pin 1, Pin 2, Pin 4) connected with Audio signal processing PCB board.

As I don’t have 0.18uF capacitor, three film capacitors are used such as 0.1uF, 0.033uF and 0.047uF film capacitors for making 0.18uF capacity.

The finished amplifier is shown in the picture above.

You can see small power supply PCB board is closely located to the TDA2030 in the right side of picture.

As the size of specially made flat EI transformer is relatively big, it takes significant space inside of chassis.

For audio input, control and output support, various components should be interconnected with Audio signal processing PCB board such as:

- 3.5mm stereo headphone socket for audio input

- 50K and 2 gang potentiometer for sound volume control

- Speaker binding posts x 2 for connecting speaker cables

For inter-connecting audio components and PCB, I’m using common AWG24 size cables.

The physical and electrical specifications of AWG24 cable is 0.511mm conductor diameter and stand 2.1A (60 degree) and up to 3.5A (75 degree).

For the TDA2030 amplifier which can product 14 ~ 18Watt, the AWG24 size of cable seems adequate enough to handle current flow among audio components and circuit PCBs.

Detail interconnection between audio components and PCBs can be seen in the picture above.

As mentioned previous steps, I divided amplifier circuit into two small PCBs such as power supply PCB board and Audio signal processing PCB board.

These PCBs are inserted to M3 metal supporters and tightly mounted on the bottom acrylic board.

Using AWG24 inter-connection cables, all audio components (e.g. potentiometer, 3.5mm stereo socket and speaker binding posts) and PCBs are inter-connected.

This is another TDA2030 amplifier made afterward the first amplifier shown in this story.

As somehow I have 4 TDA2030 chips, totally two sets of amplifiers are made using now obsolete audio chips.

For the second amplifier, I’m using toroidal transformer and I didn’t divided amplifier circuit into two PCBs.

It was a good chance to compare audio quality of two amplifiers using the same TDA2030 but differently made with slight different electronic parts.

The first amplifier introduced in this story is a little bit better because high frequency of hissing noise is not heard than the second.

Maybe locating bypassing capacitors (220uF and 0.1uF to TDA2030 pin 3/5) near to the audio chip reducing high frequency oscillation and better noise filtering from power supply lines.

For amplifier utilization, usually I’m connecting PC to the amplifier for watching youtube and movies.

If you hearing high pitch of squeal noise from speakers, disabling PC microphone input sometimes improve audio quality. (You can easily find microphone input disabling method from Internet)

Anyway this amplifier is becoming dedicated PC speaker amplifier to me for sometimes.

Thanks for reading this story…..