malcolm mellersh
- Oct 31, 2021
- 12
- Joined
- Oct 31, 2021
- Messages
- 12
Having built the amp with all the recommended components I have a growling speaker output and a rd hot positive rail. If I unplug the speaker, the rail cools down. What's the problem?
You can access the circuit from www.circuitbasics.comHello,
Can you post the used schematic?
That way we can see what is going on.
Is it the one in the attached PDF?
Bertus
Very true. The power supply is 29VDC negative and 29VDC positive. The input and output are both groundedYour circuit has no power supply voltages.
Your schematic does not show the speaker connected to 0VDC.
The output of the amplifier should measure 0VDC.
Yes. That's itHello,
So, this is the page you are using:
https://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/
Bertus
All grounds together. I have checked and signal ground and power ground are radially led to a single point.Hello,
Here is the schematic from that page:
View attachment 53153
Did you connect ALL the ground connections together?
Did you also install Rsn and Csn?
Bertus
It's the TFHello,
Wich version of the LM3886 are you using?
There are the LM3886T and the LM3886TF.
Bertus
I'm aware of the heat sink. Why is my speaker growling etc.Hello,
How large is the heatsink?
The TF version will likely need a larger heatsink, as the case has a plastic cover.
Bertus