Search found 14 matches

by dneilsen
Wed Jul 22, 2020 11:29 am
Forum: JLM Audio Kits
Topic: Passive Controller Build Thread Ver 1 & 2
Replies: 47
Views: 36297

Re: Passive Controller Build Thread Ver 1 & 2

Hi Joe I have built the controller along with the tascam breakout pcb and I am not getting any sound out at all. I suspect the issue lies in the ICB connections on the 26 wire ribbon cable and I am in the process of getting more connectors for this. Can you please confirm that I have the dual 10k po...
by dneilsen
Fri Jul 17, 2020 1:50 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

So I just came back to my bench to do some more testing and now everything is fine.
I put it back together and all the voltages are correct.
I have absolutely no idea why but I guess as long as its working....
by dneilsen
Fri Jul 17, 2020 11:17 am
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

Done some further testing. I placed a piece of thick paper between the boards and the frame at the front of the unit to test there is no shorts there. 20200717_110816.jpg As you can see in the photo the only components actually touching the frame are the two pots, the 3 switches and the transformer....
by dneilsen
Fri Jul 17, 2020 10:03 am
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

So after doing some more testing I believe that the BIO500V2 pcb may be fine. If I unscrew the BIO500v2 pcb from the 500 module frame and sit it on a piece of plastic (cd case) the input and output xlr 2 & 3 differences are all 1.23 VAC, as they are supposed to be. But if I screw it back into the 50...
by dneilsen
Fri Jul 17, 2020 8:14 am
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

I have narrowed down the issue to the BIO500V2 pcb by swapping the pcbs and transformers. I am at a loss as to how any issue has happened on this pcb because it was literally just unscrewed, placed on the bench and then screwed back into place. Not soldering or alterations at all. Here are photos bo...
by dneilsen
Thu Jul 16, 2020 5:34 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

I completely removed the LA500sc pcb and used solder wick to remove all extraneous solder, including the short (cant believe I didnt see that before). I reseated the optos at the same time and removed any logs from the underside. Gave it a really close visual inspection and everything looks to be ok...
by dneilsen
Thu Jul 16, 2020 2:42 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

Is it possible I damaged a component with the soldering iron / heat when removing / installing the optos?
I was careful but was quite fiddly and the angles for access were not great.
by dneilsen
Thu Jul 16, 2020 1:58 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

I put some vocal audio through to test. Sounds fine (as you would expect) with the GR/VU switch in the off position. I move the GR/VU switch to the GR position with threshhold and makeup fully anti-clockwise. Signal starts to distort. Lightly but certainly noticable. Moving threshhold pot applies co...
by dneilsen
Thu Jul 16, 2020 12:57 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

Sorry,
Yes, both makeup and threshhold pots are bot fully anticlockwise.
Yes the ribbon cables are connected correctly.
by dneilsen
Thu Jul 16, 2020 12:20 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

Hi Joe Photos https://www.dropbox.com/sh/ewc0cxfvg8nfjvi/AABRxLw7a1aU5sZj69ilIT93a?dl=0 Obviously, it was not easy to remove/install optos without removing the board (soldered to switches) so positioning is not the best but I believe they are installed correctly. Something else I have noticed just n...
by dneilsen
Thu Jul 16, 2020 10:26 am
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

I am having an issue with on of my LA500A units. I built my first LA500A several years ago and it has been great. Absolutely love it so I decided to buy a second one so I can have a linked pair (with a matched opto set) but now I am having trouble with the old unit I am using a JLM 500 extension cab...
by dneilsen
Tue Nov 28, 2017 1:52 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

Just confirming.
All fixed. :)
by dneilsen
Tue Nov 28, 2017 1:03 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

Dammit. Looks like i have put the LED Diode in the wrong way (Flat side is towards the square which is wrong). Doh! ok, ill swap it around. For a guy that hasnt soldered anything more than cables for about 30 years I guess that one mistake in a build is not too bad :lol: Just shows how easy these ki...
by dneilsen
Tue Nov 28, 2017 10:15 am
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 170
Views: 154603

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

Just finished my first LA500A kit and it sounds great. I have noticed one small issue with my build though. When I enable the slow attack mode the yellow LED does not light. I do not have a massive understanding of electronics and was hoping someone can point me as to where I should start to look fo...