SOLVED Gator/Chuck's Hellbender- PCB issue (mids cut volume)

[Synchrony Pedalworks]

@Chuck D. Bones and @The Gator made a great option for the Hellbender, but I've had some trouble with my PCB. The pedal will work with my PCB, and tonally, it sounds like the Hellbender demos. However, when I reduce my mids, the volume will significantly drop. I've double checked the parts and I didn't see any wrong values. I did swap out the transistors and BS170 to make sure a device wasn't faulty, but I didn't have any significant improvement. I don't think there is any cold solder joints, but more eyes on the board would help. Below is my schematic and a link to the original schematic on Gator's post. I appreciate the help!

Thread 'T W on the BB with Chuck and Gator: Hellbender/Pagebender Hybrid'

Mar 23, 2025

Yes, I abreviated "This Week on the Breadboard". Please forgive me lol...
Chuck gave me permission to post this here and really, where else would I post it?
I had purchased a couple of fuzz pedals that I really enjoy. The Deep trip Hellbender and the Page Bender. They are both great sounding fuzz pedals. But, they take up a lot of room. I traced both of the circuits. I drew them up and shared them with Chuck. I told him I wanted to make one circuit that did the job of both of these. He was of course gracious and helped me figure out how to simplify and combine the sounds. The ending...

• The Gator
• Replies: 42
• Forum: Chucks Boneyard

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[Synchrony Pedalworks]

Well, I figured out my issues. When creating the PCB, I must have used a footprint that was not comparable to the BC459c's and the BS170. Once I flipped those three devices, it worked like a champ!

 

[Chuck D. Bones]

If Q1 was backwards, the bias would be so far off that I doubt any signal would get thru. Q4 might work backwards, but it would screw up the bias on Q3 big time. Also Q1 & Q4 would not be sensitive to the MIDS knob. Q5 would definitely have a problem if it was in backwards. The body diode would turn on, effectively shorting D to S. That's gotta be the culprit.

Glad you got it working!

The lesson here is don't assume that a footprint is correct just because it's in a library.

 

[Synchrony Pedalworks]

@Chuck D. Bones Thanks! I am trying to learn some of the engineering, so I appreciate the technical explanation.

 

[The Gator]

I'm glad you figured it out. It's pretty cool circuit. I use it on stage for a couple of songs where I like to get that real late 60 sound. When I'm building the board I find two matched capacitors for the mid cut. I try to get him as close as possible and measure the value of those components. It's nitpicky but it really makes the mid-range control work well.