Hello Erik, I started a combo build of this amp with a speaker that I had and ran across a problem with the output circuit. This amp is producing a little more hum than the first one that I made and the 2nd gain was too much for my speaker. Think the speaker coil is half baked.
I have a new speaker to order in a couple weeks. When I get the new speaker, I'll be able to troubleshoot the output circuit. It needs capacitors on both sides to the speaker, but I won't know what value to use till I get the new speaker. It could be anywhere from 220uf to 10uf.
The speaker I had couldn't handle the extra gain, but did sound good with 3.3uf caps in the output circuit.
Bought a new WGS Veteran 10" 20watt 8ohm speaker that can handle 93 decibels and started back at trying caps when I started having trouble with the amp. Having to go back trough the amp and put some distance between things to get rid of some interference. Also going back to 1 input, think that was a good bit of trouble for me too.
Should be done with it soon, I'll let you know what the results are.
Been reading on the net about a lot of people having trouble with the 386 chips producing a lot of unwanted noise. It may be a production flaw that appears in some and not others. I've built 2 amps without issue, but this 1 is giving me grief.
Hey Erik, I got the problem sorted with the amp. Added 10uf caps on each output line, used just 1 volume pot as a master volume and added a B100k tone pot with a 100n cap. Here's a new schematic to help out.
Paul Craig
Hello Erik, I started a combo build of this amp with a speaker that I had and ran across a problem with the output circuit. This amp is producing a little more hum than the first one that I made and the 2nd gain was too much for my speaker. Think the speaker coil is half baked.
I have a new speaker to order in a couple weeks. When I get the new speaker, I'll be able to troubleshoot the output circuit. It needs capacitors on both sides to the speaker, but I won't know what value to use till I get the new speaker. It could be anywhere from 220uf to 10uf.
Mar 29, 2016
Paul Craig
The speaker I had couldn't handle the extra gain, but did sound good with 3.3uf caps in the output circuit.
Bought a new WGS Veteran 10" 20watt 8ohm speaker that can handle 93 decibels and started back at trying caps when I started having trouble with the amp. Having to go back trough the amp and put some distance between things to get rid of some interference. Also going back to 1 input, think that was a good bit of trouble for me too.
Should be done with it soon, I'll let you know what the results are.
Been reading on the net about a lot of people having trouble with the 386 chips producing a lot of unwanted noise. It may be a production flaw that appears in some and not others. I've built 2 amps without issue, but this 1 is giving me grief.
Apr 19, 2016
Paul Craig
Hey Erik, I got the problem sorted with the amp. Added 10uf caps on each output line, used just 1 volume pot as a master volume and added a B100k tone pot with a 100n cap. Here's a new schematic to help out.
May 26, 2016