Omega volume pot crackle / issue

[Brymus]

I have my Omega by ROG (built per the schematic) http://runoffgroove.com/omega.html
And have already replaced the volume pot once because it only had sound at one setting after alot of use and crackled really bad when turning.
It still crackles when turning it ,but so far still works through the range.
Has any one else had this problem ?
Is this part of the design or have I done something wrong ?
I built it on my breadboard to verify and got the same issue...Have triple checked against the schematic as well.
I also tried a .22uf - 1uf cap/caps before the volume pot but got no sound that way ?
If someone knows how to fix this I would be extremely grateful,
I love my Omega but dislike the crackle and am worried I will have to keep replacing volume pots.
Thanks,Bryan

[John Lyons]

Yeah, it's not correct. It should be silent.
I'm not sure how you built yours but I made the
10k at the source a fixed 10K resistor and took
the output off the source through a 4u7 cap to
a 100k pot.

I had an intermitant skipping/re biasing sound on
one of my Omega builds.

Measure the negative side of the 4u7 cap and
see if you get any DC. If so then the cap is leaking DC
which it is supposed to block nearly 100%...
Try a new 4u7 if you get DC after the cap

[Brymus]

Thanks for that info John !
If I understand you correctly you took the signal prior to the 10K resistor off the source then into the 4.7uf cap then to a  a 100k pot for volume?
Did you still include the 1m pull down resistor or is the 100k pot enough to prevent pops?
Yeah thats was the one thing I changed from the schematic ,is I used a 1uf nonpolarized film cap instead of the 4.7uf polarized cap.
I will try what you said and report back.
Thank You,Bryan

[John Lyons]

The 100K will be your new pulldown. 100K resistance to ground all the time, bleeding off any voltage (pops).
So no 1M needed now. Any time you have a resistor(or pot)  to ground after a cap at the output that's your pulldown.

What at I have is 10k from source to ground.
4u7 (or whatever cap you choose) directly connected to the source
and then after the cap to the 100k volume pot.

I have one built as stock as well that works fine though as well...

[earthtonesaudio]

DC across the pot is a recipe for "noisy while adjusted."  Do like John did, and relocate the volume control to after the output cap.  However, I'd use a 10k for the volume, which, when turned down, will retain more highs compared to a higher value pot.

[John Lyons]

That's true...it is a low Z output so you only need the 10K pot and you preserve some high end.
Probably not that much really though. Why would you be using the the pot that low anyway.

[earthtonesaudio]

That's true...it is a low Z output so you only need the 10K pot and you preserve some high end.
Probably not that much really though. Why would you be using the the pot that low anyway.

Agreed.  It's good to put things in perspective.

[Brymus]

The 100K will be your new pulldown. 100K resistance to ground all the time, bleeding off any voltage (pops).
So no 1M needed now. Any time you have a resistor(or pot)  to ground after a cap at the output that's your pulldown.

What at I have is 10k from source to ground.
4u7 (or whatever cap you choose) directly connected to the source
and then after the cap to the 100k volume pot.

I have one built as stock as well that works fine though as well...

Alright  +1
Finally had time to try your advice.
I just finished modding mine to the way you described,and that fixed it.(no more scratchy pot)
It sounds better now too, as well, it has a crisper, cleaner sound, but still gets fat with the range dialed up.
After reading your post I understood why the way I tried didnt work > because it was blocking DC off the source/not just the pot.
Basically turning it off.
I re-used the 10K pot that was already in there and its still plenty loud.
Thank You,VERY,VERY much John

I totaly recomend anyone building an Omega to do it that way instead 

[John Lyons]

Nice!
Glad it worked.