SOLVED Mofeta bass and treble do nothing

F

frustrated

New member
This is the second one I built, first one was perfect. My buddy liked it so much he asked me to build him one. It sounds good except the bass and treble controls do absolutely nothing. They 100% work on my first one. Measured the pots, they are working fine, I don't see any incorrect resistors, pretty sure the caps were all correct, some of them the markings are obscured by other components. Where should I look around? What went wrong?

Please and thank you.
 

Attachments

  • PXL_20230611_164524048.jpg
    PXL_20230611_164524048.jpg
    443.3 KB · Views: 53
Last edited:
Sort by date Sort by votes
Do you have a 100n cap and a wire? If so, you’ve got an audio probe in the making:

TUTORIAL - Troubleshooting 101

There comes a time for every builder to spend multiple hours soldering, wiring, and breadboarding a certain circuit just to have it work incorrectly, if at all. This could happen on your first build or any build after that. This write up is to help you in your quest to figure out why it isn't...
forum.pedalpcb.com forum.pedalpcb.com
 
Upvote 0 Downvote
benny_profane said:
I'm not sure that that's an effective way to engage with folks who are trying to help you. Keep on like that and I doubt anyone is sticking around for you

The tone stack comprises C12, C13, C14, R11, and the three pots followed by the coupling capacitor, C15. Please verify that 1) the parts are correct and 2) you have continuity where appropriate. We can't see any values from the pictures you posted. We also can't visually confirm the integrity of your off-board wiring.


View attachment 50372
Click to expand...
Ok, adult Fluke continuity test.
Treble/Bass connectivity:
Lug 1/Lug 1: no
Lug 1/Lug 2: yes
Lug 1/Lug 3: yes
Lug 2/Lug 1: no
Lug 2/ Lug 2: no
Lug 2/ Lug 3: no
Lug 3/ Lug 1: no
Lug 3/ Lug 2: no
Lug 3/ Lug 3: no

Retested continuity between those caps and pots and I'm seeing connectivity.

Since the pedal functions, just not the treble and bass, how would I use an audio probe to find the issue?
 
Upvote 0 Downvote
Can you verify the connections to the MID pot too? I’m really not sure what to tell you if all values and connections are verified.

Are all pot values correct? Are all traces verified?

You’re describing a situation where the BASS and TREBLE pots are being bypassed and the MIDS pots is behaving as a low pass filter.
 
Upvote 0 Downvote
frustrated said:
Ok, adult Fluke continuity test.
Treble/Bass connectivity:
Lug 1/Lug 1: no
Lug 1/Lug 2: yes
Lug 1/Lug 3: yes
Lug 2/Lug 1: no
Lug 2/ Lug 2: no
Lug 2/ Lug 3: no
Lug 3/ Lug 1: no
Lug 3/ Lug 2: no
Lug 3/ Lug 3: no

Retested continuity between those caps and pots and I'm seeing connectivity.

Since the pedal functions, just not the treble and bass, how would I use an audio probe to find the issue?
Click to expand...
Ok actually I just tried lug 1 to lug 1 again and there is continuity there. Bass and treble lug 1s are connected.
 
Upvote 0 Downvote
It looks like a break where R11 goes in the circuit might explain the behavior you are having. May be worth another look to make sure the resistor is good even if you have continuity to each end of it.
 
Upvote 0 Downvote
 
Upvote 0 Downvote
have you confirmed the pot values for the 3 tone controls are correct? check them with your meter even if the labels are right. the resistance values for the three of them could be a factor if they were swapped into the wrong places.
 
Upvote 0 Downvote
zgrav said:
have you confirmed the pot values for the 3 tone controls are correct? check them with your meter even if the labels are right. the resistance values for the three of them could be a factor if they were swapped into the wrong places.
Click to expand...
Ahhh I don't know how I didn't notice it before but I had the 25k in the 250k spot and vice versa. I could've sworn I checked that. Man that was stupid. I swapped them, now it looks like they're working. Thanks guys, as usual, user error.
 
Upvote 0 Downvote
frustrated said:
Ahhh I don't know how I didn't notice it before but I had the 25k in the 250k spot and vice versa. I could've sworn I checked that. Man that was stupid. I swapped them, now it looks like they're working. Thanks guys, as usual, user error.
Click to expand...
Congrats! I wish I would have said something when I thought about it a few days ago.
 
Upvote 0 Downvote
You must log in or register to reply here.

Similar threads

Z
  • Solved
SOLVED Mofeta Build Normal Channel not working + more
Replies
3
Views
375
ZoraAD
Z
A
  • Question Question
Box and All (tone job) treble/mids issue
2
Replies
23
Views
2K
zeropluszero
zeropluszero
L
  • Question Question
Sushi Box FX Particle Accelerator Bass-Pot not responsive (+other issues)
Replies
11
Views
913
Feral Feline
Feral Feline
eh là bas ma
  • Solved
SOLVED Aion's Beta preamp : Treble pot issue
Replies
10
Views
1K
eh là bas ma
eh là bas ma
Svenson007
Greer Soma 63 treble barely does anything
Replies
2
Views
473
Svenson007
Svenson007
Back
Top