Amplify ISD1820 module output by LM386 amplifier ..#2

Thread Starter

sotiraw

Joined Nov 5, 2022
8
You have shorted one of the ISD1820 speaker outputs to ground. Below is the diagram from the datasheet of how to connect it to an LM386.
View attachment 135435
i try to use an lm386 module, that has already the connection parts on the side of the lm386, so the connections on the lm386 are on the attached file. Do i need to do the same way connection of the output of the 1820 like this you have here? does this cover this connection of the module ? because if i send them directly i hear nothing.
the module is like this and the picture is taken from the second pdf with the schematic
https://www.openimpulse.com/blog/pr...egory/lm386-audio-amplifier-module-high-gain/

Mod: Link to old thread.
https://forum.allaboutcircuits.com/...output-by-lm386-amplifier.140223/post-1180156
 

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seanstevens

Joined Sep 22, 2009
164
ISD1820 seems to have a differential output. I would imagine if you just connected the +speaker output from your ISD1820 to the input of your LM386 and obviously with the common ground between your two boards, you should get something out of the amp speaker.
 

seanstevens

Joined Sep 22, 2009
164
OK, then maybe provide some information as to what exactly is your ISD1820 module or the circuit using it etc. Does the module work at all, does it give any output at all, are you using it correctly, are you sure you have recorded on it etc?
 

Thread Starter

sotiraw

Joined Nov 5, 2022
8
OK, then maybe provide some information as to what exactly is your ISD1820 module or the circuit using it etc. Does the module work at all, does it give any output at all, are you using it correctly, are you sure you have recorded on it etc?
please let other people reply that already know what i am talking about and are familiar with this module. thank you for your time

@AlbertHall
 

MrChips

Joined Oct 2, 2009
27,651
please let other people reply that already know what i am talking about and are familiar with this module. thank you for your time
Sounds like a criticism or complaint. Please be respectful to others.
The responder made valid suggestions and is only trying to be helpful.
 

LowQCab

Joined Nov 6, 2012
2,620
If You would describe in detail the performance that You expect,
You will receive more useful answers.

A LM386 Amplifier is just about useless in this project, as the project has been presented.
You will probably need a decent Bridge-Amp-Chip, and a more substantial Power-Supply.
More Power is not free.
.
.
.
 

Ya’akov

Joined Jan 27, 2019
6,853
Sounds like a criticism or complaint. Please be respectful to others.
The responder made valid suggestions and is only trying to be helpful.
To amplify what @MrChips said, it is also self-defeating. There are many people here who have never seen the module you are using but with a little information about it could solve the problem you can’t do yourself. It is a mistake to think that someone have to have experience with a specific implementation of something in order to know how to make it work.

It is in your own self interest to answer questions from members here who are trying to help. So aside from appearing rude, it is also silly.
 

MisterBill2

Joined Jan 23, 2018
13,689
The very first step should be to connect a suitable speaker to that ISD1820 speaker output and see what you get out of it. Then you will know if it is even functional. A non-functional device is not likely to provide any useful outputto drive an external amplifier IC device.

Short circuiting one side of a differential speaker output to common is often enough to destroy the stage driving the output. In that case, you will need a replacement ISD1820 because there will be no output from the one that you have.
 

ericgibbs

Joined Jan 29, 2010
16,748
Bill,
If you use the setup shown Post #9, using a LM386 with a 10R across the ISD1820 audio output, there is NO Connection to Common/0V on the audio output lines.
I have an almost identical system working on the bench, so please stop posting about projects and devices you have not researched, as it detracts from the work of other posters and puts doubt in the mind of the TS.

E
EG57_ 269.png
 

MisterBill2

Joined Jan 23, 2018
13,689
Bill,
If you use the setup shown Post #9, using a LM386 with a 10R across the ISD1820 audio output, there is NO Connection to Common/0V on the audio output lines.
I have an almost identical system working on the bench, so please stop posting about projects and devices you have not researched, as it detracts from the work of other posters and puts doubt in the mind of the TS.

E
View attachment 281229
My comment was addressing the circuit shown in post #1, which shows a differential output connection arrangement connected with one side tied to the system common. I was not referencing any other connection arrangement in any other post. The sigle ended amplifier circuit shown in your post is not the same, nor is it even slightly similar to that module referenced in post #1.


Certainly I should have made that clearer than I did.
And certainly it is usually a poor choice to ground one side of a bridge connected output of an amplifier. And THAT is what I was addressing.

And why is it incorrect to first verify that the input device is functional, when a newly built amplifier does not deliver any output?
That is basic trouble-shooting step number two, right after verifying the power is connected.
 
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