Laundryroom David
Keyboard Cowboy 🤠
I’m troubleshooting a couple of recent builds of this one that have the exact same issue.
Has anyone else built this per the BOM?
If so, does anyone else get a loud hum when both the “bottom” and “edge” switches are engaged and gain is up past about 11 o’clock?
At full gain the hum sounds like an F (like 3rd fret on the D string).
Turning guitar volume down to zero has no effect, nor does running a buffer before or after the pedal. Turning the gain down on the pedal causes the pitch of the hum to go up a few steps and then cease once the gain knob is down to about 11 o’clock. Disengaging either tone switch (or both) ends the hum even with the gain dimed.
In other words, in stock OD-1 mode, it’s not an issue. In Fulltender mode with gain above 11 o’clock and both tone switches engaged, hum-a-palooza.
I cannot remember the last time I had to troubleshoot a build so extensively. I have inspected, tested, reflowed. Buffer in front, buffer behind, no other pedals in the chain, other pedals in the chain, different power supplies (Boss 9v, PP2+). I separated the input and output wires and isolated them as much as possible. Still no love.
Nothing gets rid of the hum and this is by no means a high gain pedal. My original Fulltender did not hum even with the gain maxed out and both tone toggles engaged.
I am wondering if there’s a problem with parts talking to each other through the rails or maybe some kind of feedback loop getting out of hand. I am (as I often say) not an engineer, nor do I even play one on tv so I don’t know if that even makes sense.
The closest thing I can liken this problem to is the way the havoc switch affects the sound of the Cannon Fodder MkI. Hence my musings about the feedback loop.
I am down the rabbit hole, tucking 47pF caps places in hopes it helps. I dunno man. Getting dark in here. Any help appreciated.
Has anyone else built this per the BOM?
If so, does anyone else get a loud hum when both the “bottom” and “edge” switches are engaged and gain is up past about 11 o’clock?
At full gain the hum sounds like an F (like 3rd fret on the D string).
Turning guitar volume down to zero has no effect, nor does running a buffer before or after the pedal. Turning the gain down on the pedal causes the pitch of the hum to go up a few steps and then cease once the gain knob is down to about 11 o’clock. Disengaging either tone switch (or both) ends the hum even with the gain dimed.
In other words, in stock OD-1 mode, it’s not an issue. In Fulltender mode with gain above 11 o’clock and both tone switches engaged, hum-a-palooza.
I cannot remember the last time I had to troubleshoot a build so extensively. I have inspected, tested, reflowed. Buffer in front, buffer behind, no other pedals in the chain, other pedals in the chain, different power supplies (Boss 9v, PP2+). I separated the input and output wires and isolated them as much as possible. Still no love.
Nothing gets rid of the hum and this is by no means a high gain pedal. My original Fulltender did not hum even with the gain maxed out and both tone toggles engaged.
I am wondering if there’s a problem with parts talking to each other through the rails or maybe some kind of feedback loop getting out of hand. I am (as I often say) not an engineer, nor do I even play one on tv so I don’t know if that even makes sense.
The closest thing I can liken this problem to is the way the havoc switch affects the sound of the Cannon Fodder MkI. Hence my musings about the feedback loop.
I am down the rabbit hole, tucking 47pF caps places in hopes it helps. I dunno man. Getting dark in here. Any help appreciated.
