I've built this twice now on the breadboard at 9v
without success. I added an emitter follower/buffer
to get some more clarity for guitar.
It has a low oscillation with the buffer and sounds choked
and misbiased built just as in the image.
I have the Stereo/unbridged version working fine with the buffer.
I tried adding more filtering but I'm not sure where else to check.
Any ideas?
(https://envirementalb.com/wp-content/uploads/2019/09/5w-Streo-Amplifier.png)
(https://lh3.googleusercontent.com/proxy/EKT3zB27Ioc4OUM5m2uamoexR3RcZbLwVTnn8wza7f2MXljr9Uid0Q8BOwXKRyyLzVMv8M3NpRtDox2EdEcLAEdE9IKZqTF3E2tQUsFCzHN4tkqvNJHHU6BGhsUZiME4p-0P)
What is the speaker ohm rating that you used in bridged mode?
Try to ground pin 13 as close as physically possible to 150nF caps ground..
(https://i.imgur.com/TT3OtSZ.jpg)
That's it! I moved a ground wire to put the .15 caps and pin 13
at the same point and it cleared up. Thank you.
I upped the 100uf at the output to 470uf also (before I changed the ground)
and that helped also. What is the affect of using .22uf rather than .15uf?
Gus:
I am using an 8 ohm speaker.
Quote from: John Lyons on February 02, 2021, 04:18:30 PM
That's it! I moved a ground wire to put the .15 caps and pin 13
at the same point and it cleared up. Thank you.
You're welcome.. :icon_wink:
Next suggestion, in case of above non-effective, should be to delete one of 150nF caps and wire the remainder one between pins 2 & 15..
(to also prevent garbage entering into different points of GND..)