Parentheses boost issues

[swanforgetter]

hey all,

working through a parentheses (on the big pcb) right now. i’ve got everything working except the boost...having a lot of trouble here. i have checked all component values and they’re correct. someone on reddit helped me out and gave me voltages on the BS170 pins and i think i’ve tracked my issue down (at least partially) to here but i’m out of ideas - his working pedal gets D - 4.66, G - 2.25 and S - .19. mine is getting a full 9V on the drain and nothing on G or S. reflowed joints on the socket, swapped out the transistor for another BS170 (all bought from tayda) and still no luck. i’ve attached a picture with highlighted resistors that don’t have current flow. any ideas?

 

[Madallop]

Yeah, that stuff's not for circuit boards. Have you seen the Basic Workflow Tips in the General Questions forum?

I have! Didn't have any issue with a Cataclysm due to that extremely helpful guide but this Parentheses is strange. I'm now having oscillation issues on the Rat end. Boost is fine now, however it further boosts oscillation when engaged. I read through some past threads, followed your directions you gave to a fellow member and trimmed all of my transistors' legs down and I have a socketed electrolytic cap (2u2 cap to a 1u-10u for less/more low end when gain is dimed) that I also shortened down so I need to check it in the morning when everyone in the house is awake. Hoping that solves my issue!

 

[Chuck D. Bones]

Check your grounds. Make sure the jacks, switches & pots all make electrical contact with the chassis. If there is paint on the inside of the box, scrape some away around all of the holes. Show us some pix of your board and box.

 

[Nostradoomus]

Are you using high output pickups?

 

[Madallop]

Are you using high output pickups?

Duncan 59/Custom Hybrid in the bridge and Dimarzio Area 67 in the neck. Even with switching to the neck, it still had the same oscillation going from the Rat part of the circuit.

Going to take some gut shots here in a sec.

 

[Nostradoomus]

Just saying most of my rat builds squeal with my BKP pickups but not with any of my lower outputs. I had to throw a tiny jfet buffer in there.

 

[Madallop]

Gut shots here. Oscillation went down slightly after trimming the transistors and cap leads but as soon as the volume on the Rat is dimed, it's immediate high pitched oscillation. I believe that the enclosure might be a good portion of my issue as my DMM doesn't pick up much continuation within the enclosure.

https://imgur.com/a/KDnW1Qv

 

[Madallop]

Update: Scraped the paint from the inside of the enclosure, put everything back together, and I still get oscillation from the Rat side with volume or gain dimed like before. Super puzzling.

Update 2: Isolated it from all of my pedals and it made a rather large difference. I also have a mini 1/2 watt amp that I was running with my pedals on a daisy chain so I've since run that on a separate power supply. So far so good. I'll update if I get anything further.