Hey Guys. First post and I need help

I'm building the hairball audio 1176 rev a right now and everything was going good (passed audio all the way through) but I wasn't getting any compression so I did a little digging and it looks from all the pictures of the completed pcb that I mounted the trim pots at a 90 degree angle to how they're supposed to be mounted. I would assume this would cause the unit to not compress because the trim pot is essentially a variable resistor and I have no way to adjust q bias.. So I tried to remove the q bias trim pot and one of the leads broke . My local electronics store has a 5k but it calls for a 2 k.. Would a 5 k hurt anything or cause problems? am I right in assuming that this is why the unit isn't compressing? (Im noticing a very tiny bit of compression at 20:1)

can't tell if this is why your unit is not compressing (problem most likely in the sidechain if it passes audio).  the 5K trim pot will work.  the adjustment range of that pot will be more sensitive (i.e. a small turn will result in more drastic resistance so slightly more sensitive to adjustment).
best,
grant

thanks for your response. I'll see about installing a 5k and I have a 2 k on order so I may just wait for that.. I hope that this is the last thing I have to do to get this thing compressing.. Like i said, it sounds like its compressing a little bit.. maybe 3-4 db.. but thats w the input control cranked (should be dropping gain by many more db i would assume)

Does anybody else have any ideas as to why it's passing audio but barely compressing? I know the q bias effects the compression but i didnt expect it to make such a massive difference.. Maybe it has something to do with all the trim pots being mounted at a 90 degree angle to what they're supposed to be? (I suppose this could allow for the signal to flow in places it shouldnt)

Ok so I mounted the trim pots correctly and they have absolutely no effect on the signal!! the meter isn't changing at all when I try to do the q bias adjustment.. Also I should add that when in gain reduction mode the meter just stays pegged to -20 db even when there's no signal.. I'm at a total loss.. Please help! Anyone!

So I guess nobody knows why the meter isnt working in gain reduction mode? I know its hard to diagnose something over the internet and i appreciate it anyways guys.

Hi and Welcome to the Forum.

Concerning your problems, best would be to post your questions in the thread that speaks of it:
http://www.groupdiy.com/index.php?topic=29981.0

And as always, use the search button and go thru the thread(s), you might find some tips on your error(s), and if you post, be specific on the test procedures that you do and that causes the fault, and post pics of your build, it always helps.

Dunno what you've done, but there is a calibration procedure to do on these units, if not done, check that first.


T.