Hi there!
Near the beginning of this year I made my first LM386-4 based amplifier and speaker circuit (some details in this thread here: https://forum.allaboutcircuits.com/...ling-capacitors-questions.166722/post-1473500 ). It's been "good enough" for all my audio experiments so far.
I'd like to add a LM386-4 based amplifier circuit and speaker to my current project, so I came back to my previous one here for reference. But I think it's natural to want to do better than we did last time so I have some more questions.
My circuit is running at 9V DC.
I should start with talking about my speaker options. Both are rated for 8 ohms, but the first is rated for 0.5 watts and has a larger heavier magnet (aside: is there any reason to prefer a heavy magnet? This doesn't seem like a "feature" to me in a half watt speaker), and the second option is 3 watts. My first build is using the 8 ohm 3 watt speaker.
From my reading on the LM386-4, I think it can power in the 0.25 to 1 watt range. Given my first speaker option maxes out at half a watt, I think I should continue to use the 8 ohm 3 watt speaker.
But if the LM386-4 maxes out at 1 watt and my speaker has "room" for 2 more... Can I get there?
I stumbled across this video today:
"LM386 Amplifier. Parallel. Double the power and performance."
I should start by saying I am taking this video with a huge grain of salt - comments are disabled and they don't offer any real "proof" of what the circuit has achieved beyond being able to make some music audible.
But it did start me down the path of looking at parallel, bridge and bridge-parallel circuits, because it's not really a problem for me to add a second LM386-4.
I found what claims to be a Bridge Parallel amplifer circuit searching the web, but beyond the diagram it's pretty light on details and it could be riddled with errors for all I know.
http://www.seekic.com/circuit_diagr...g_LM386_as_BTL_amplifier_circuit_diagram.html
Still, I am going to try to breadboard this and see what kind of results I get.
I have another question related to this, though. Assuming a bridge-parallel would work for me, is it still possible to add things like a gain control potentiometer (normally done as a RC circuit between pins 1 and 8 when using a single IC)? I know both ICs are supposed to be working as identically as possible (except the polarity reversal).
Alternatively, reading some other threads on these forums regarding lm386 and adding a Push-Pull Output stage was also suggested:
http://www.bristolwatch.com/radio/lm386_power_amp.htm
This is also intriguing idea, and I may even have all the necessary components laying around, but I do note that the author states:
"The output is several watts as opposed to 400 mW."... I'm not sure if they consider "several" as more than 3.
Assuming I do have all the suitable components I will also try to breadboard this and see.
I will update this thread with my results, but I'd appreciate any input or suggestions anyone has, even if it's "don't bother, because..."
Near the beginning of this year I made my first LM386-4 based amplifier and speaker circuit (some details in this thread here: https://forum.allaboutcircuits.com/...ling-capacitors-questions.166722/post-1473500 ). It's been "good enough" for all my audio experiments so far.
I'd like to add a LM386-4 based amplifier circuit and speaker to my current project, so I came back to my previous one here for reference. But I think it's natural to want to do better than we did last time so I have some more questions.
My circuit is running at 9V DC.
I should start with talking about my speaker options. Both are rated for 8 ohms, but the first is rated for 0.5 watts and has a larger heavier magnet (aside: is there any reason to prefer a heavy magnet? This doesn't seem like a "feature" to me in a half watt speaker), and the second option is 3 watts. My first build is using the 8 ohm 3 watt speaker.
From my reading on the LM386-4, I think it can power in the 0.25 to 1 watt range. Given my first speaker option maxes out at half a watt, I think I should continue to use the 8 ohm 3 watt speaker.
But if the LM386-4 maxes out at 1 watt and my speaker has "room" for 2 more... Can I get there?
I stumbled across this video today:
"LM386 Amplifier. Parallel. Double the power and performance."
I should start by saying I am taking this video with a huge grain of salt - comments are disabled and they don't offer any real "proof" of what the circuit has achieved beyond being able to make some music audible.
But it did start me down the path of looking at parallel, bridge and bridge-parallel circuits, because it's not really a problem for me to add a second LM386-4.
I found what claims to be a Bridge Parallel amplifer circuit searching the web, but beyond the diagram it's pretty light on details and it could be riddled with errors for all I know.
http://www.seekic.com/circuit_diagr...g_LM386_as_BTL_amplifier_circuit_diagram.html
Still, I am going to try to breadboard this and see what kind of results I get.
I have another question related to this, though. Assuming a bridge-parallel would work for me, is it still possible to add things like a gain control potentiometer (normally done as a RC circuit between pins 1 and 8 when using a single IC)? I know both ICs are supposed to be working as identically as possible (except the polarity reversal).
Alternatively, reading some other threads on these forums regarding lm386 and adding a Push-Pull Output stage was also suggested:
http://www.bristolwatch.com/radio/lm386_power_amp.htm
This is also intriguing idea, and I may even have all the necessary components laying around, but I do note that the author states:
"The output is several watts as opposed to 400 mW."... I'm not sure if they consider "several" as more than 3.
Assuming I do have all the suitable components I will also try to breadboard this and see.
I will update this thread with my results, but I'd appreciate any input or suggestions anyone has, even if it's "don't bother, because..."