Capacitors needed when using an audio amplifier?

Click For Summary
SUMMARY

The discussion centers on the necessity of capacitors when using the TDA2822 audio amplifier with a Maximite computer. Participants confirm that the capacitors required for DC blocking are already mounted on the PCB of the amplifier, thus eliminating the need for additional capacitors on the output pins. While some argue that using capacitors is a necessary evil due to the single-ended supply design of the TDA2822, others emphasize their essential role in preventing DC from reaching the speakers. Overall, the consensus is that no extra capacitors are required if the existing ones are present on the PCB.

PREREQUISITES
  • Understanding of audio amplifier circuits, specifically TDA2822 design
  • Knowledge of DC blocking capacitors and their function in audio applications
  • Familiarity with PCB design and component placement
  • Basic principles of audio signal processing and impedance
NEXT STEPS
  • Research the specifications and applications of the TDA2822 audio amplifier
  • Learn about the design and function of DC blocking capacitors in audio circuits
  • Explore the advantages of using balanced supply configurations in audio amplifiers
  • Investigate the impact of capacitor size and ratings on audio output quality
USEFUL FOR

Audio engineers, hobbyists working with audio amplifiers, and anyone involved in designing or troubleshooting audio circuits will benefit from this discussion.

toasterman
Messages
1
Reaction score
0
Hello,
I am using this little audio amplifier with my Maximite computer: https://www.amazon.com/dp/B07MQ44KLP/?tag=pfamazon01-20
I know that it's a best practice to use capacitors on the audio output from amplifier chips to filter out any extra DC current. I am under the impression that the capacitors on this amplifier circuit will take care of that. Is this true, or should I use capacitors on the output pins also?

Thank you.
 
Engineering news on Phys.org
I believe the capacitors you require are mounted on that PCB.
https://www.electroschematics.com/4375/tda-2822-stereo-amplifier/
 
  • Like
Likes davenn, berkeman and hutchphd
toasterman said:
I know that it's a best practice to use capacitors on the audio output from amplifier chips to filter out any extra DC current.

Thank you.

I wouldn't call it best practice, more a necessary evil if you don't have split supply rails.

Given the choice you would do balanced supply and have an output stage that does not have appreciable DC off set since DC blocking capacitors have to be huge to not impact the output impedance at low (bass) frequencies and need to have obnoxious ripple current ratings for anything more than a few W of output power.

The TDA2822 is single ended supply, so it would need them unless you run it in bridge mode, they look like they are on the PCB already!
 
toasterman said:
Is this true, or should I use capacitors on the output pins also?

no extra ones required
Baluncore said:
I believe the capacitors you require are mounted on that PCB.
https://www.electroschematics.com/4375/tda-2822-stereo-amplifier/
Agreed, yes they are :smile:

essenmein said:
I wouldn't call it best practice, more a necessary evil if you don't have split supply rails.
No, they are essential
essenmein said:
Given the choice you would do balanced supply and have an output stage that does not have appreciable DC off set since DC blocking capacitors have to be huge to not impact the output impedance at low (bass) frequencies and need to have obnoxious ripple current ratings for anything more than a few W of output power.

not to mention not letting DC pass to the speaker(s) which is a bad thing
 
Most likely this can only be answered by an "old timer". I am making measurements on an uA709 op amp (metal can). I would like to calculate the frequency rolloff curves (I can measure them). I assume the compensation is via the miller effect. To do the calculations I would need to know the gain of the transistors and the effective resistance seen at the compensation terminals, not including the values I put there. Anyone know those values?

Similar threads

  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
Replies
13
Views
3K
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 37 ·
2
Replies
37
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 10 ·
Replies
10
Views
6K
  • · Replies 7 ·
Replies
7
Views
3K