Search found 3 matches

by flyingcloud
Tue Jan 12, 2021 5:15 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 211
Views: 461822

Re: LA500A opto comp leveling amp BUILD THREAD 500/51X

ok sorry for taking you along for this ride- looks like the problem could be that the ne5532p opamp on the sc board was installed in the wrong orientation. I noticed that someone here had a similar issue a few years back. I removed the opamp and the needle was no longer pinned with power on. flipped...
by flyingcloud
Tue Jan 12, 2021 10:33 am
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 211
Views: 461822

Re: LA500A opto comp leveling amp BUILD THREAD 500/51X

Ok so I replaced the resistors and went through and hit every solder point..it fires up without exploding! it will pass audio, but the meter is pinned and the when turning the threshold pot cw audio stops completely. makeup gain seems to be working... any tips for troubleshooting this? thank you! Hi...
by flyingcloud
Mon Jan 11, 2021 4:42 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 211
Views: 461822

Re: LA500A opto comp leveling amp BUILD THREAD 500/51X

Hi Joe, I just completed this build. everything seemed to go smoothly- but when I powered the unit up I heard a crackle, saw smoke and immediately cut power. turns out R15, R16 (10R) on board SCv3 both completely fried. here are some photos of the boards: https://www.dropbox.com/sh/yo4ow2i66yt7zg4/A...