SOB back and forth...

[Dan0h]

This has been an adventure. I am still going back and forth with my first build. The SOB. I was able to trace down all the issues and get it working unboxed, sounded awesome. So I boxed it and decided I should try biasing it per spec too see if the sound would get even better. For some reason I was only able to get 3volts to Q2 even with trim full blast, Q3 solid 4v and Q1 solid 1.6v. What’s worse is now only sound when in bypass, I traced the signal all the way to the output and there is signal but no sound. So I unboxed it and still no sound and when checking voltage at Q2 unboxed full 9 volts and trim has no affect. Did I fry Q2? I’ve already decided to order a new SOB when they are available so I’m ok with this one being my learning curve but I really would like to figure out what the hell is going on with it. Any thoughts? By the way I’m officially hooked. General Tso and a Black hole Sunn ready to start this weekend, and a second SOB hopefully soon, Peadalpcb, Mouser, lovemyswitches, Tayda, and Amazon packages have been flocking to my porch the last week...

 

[Dan0h]

Side note, R1 is not missing its on the underside. I had to replace it because I noob clipped it when redoing the FS hookup. It’s there and working.

 

[untamedfrontier]

So if it worked fine before it was boxed, sounds like you may have a grounding problem. I know some suggest filing a bit of the paint off of the holes in the enclosure to help out with that.

May be also shorting out on the bottom of the board as well with that dual pot since they aren't insulated like the others

 

[Dan0h]

So if it worked fine before it was boxed, sounds like you may have a grounding problem. I know some suggest filing a bit of the paint off of the holes in the enclosure to help out with that.

May be also shorting out on the bottom of the board as well with that dual pot since they aren't insulated like the others

I thought the same thing, but it also didn’t work when I unboxed it making sure the dual pot was not touching. Boxing it did something, I thought it might have broken loose one of my noob solders but I’m still able to trace signal to the end. The hugest change is now the Q2 trim has no effect on Q2 and its reading full 9 volts. Maybe I damaged that trim pot?

 

[untamedfrontier]

You could always try to isolate the Q2 trim with your multimeter and see if it's still variably resisting

 

[Dan0h]

You could always try to isolate the Q2 trim with your multimeter and see if it's still variably resisting

Will do that tonight. Thanks.

 

[zgrav]

if you are still having problems getting it working, post clear pics of each side of the PCB and the wiring on your jacks.