Fuzz pedal is great but could use more low end

[Kerosenetrewthe1]

Hey all,

I had started a thread recently but with the help of this forum, the issues were worked out. Thank you.

I am still working on my first build, a mammoth fuzz clone. It's all put together but I'm surprised at how much low end is sucked out of my signal. This is the Mastadon pedal kit which is supposed to be bass guitar friendly and let some of the low end signal to pass through the circuit. This sounds great on my electric guitar, but not so much on my bass. I was curious if there's a resistor, transistor, pot, or cap that I could replace to allow more low end to flow through? I don't know if it's possible, but I thought I would ask. This has been a great building experience to get my feet wet in circuits. I'm really enjoying the learning curve.

Here's the schematic for the circuit.

[PRR]

The highest poles are 52Hz. So it slightly shaves the lowest few notes of Bass, but probably not enough to matter.

You could try C1= 470nFd, C3= 220uFd.

However I would also look for build errors.

[Kerosenetrewthe1]

The highest poles are 52Hz. So it slightly shaves the lowest few notes of Bass, but probably not enough to matter.

You could try C1= 470nFd, C3= 220uFd.

However I would also look for build errors.

Thanks for the reply and suggestions. The build seems to work fine as all the controls do what they are suppose to do. Anything in particular to look at that would cause the lack of low end?

[chuckd666]

I'd recommend checking the supplied capacitors are the correct ones, and yes to make sure you don't have any bad solder joints and ensure things are going where they're supposed to.

[Kerosenetrewthe1]

I'd recommend checking the supplied capacitors are the correct ones, and yes to make sure you don't have any bad solder joints and ensure things are going where they're supposed to.

Thank you.

I took the circuit out of the pedal house to diagnose some things. Looks like the bi-color LED light was causing my popping when I would switch the pedal on and off. So I unhooked one of the connections to the LED so now the light only comes on when the pedal is engaged. I prefer this anyway as it's not confusing on my pedal board which pedal is engaged. One issue solved.

One last thing though, when the circuit was out of the metal house, I got zero ground buzz. But when I installed the circuit back into the housing, the pedal hums a lot. How can I check for ground loops?

[GGBB]

Checking for ground loops is essentially a matter of drawing a diagram of all the ground paths in your build, including the enclosure. It is possible that this is not a ground loop in the pedal itself (that's not impossible but it is unusual) but something else - bad ground connection, interaction with other pedals (possibly ground loops), power supply issues... Lots of threads here on all that stuff. Does it hum with battery power? By itself (no other pedals connected)? Is it only with one power supply?

[Gus]

measure the collector voltages at min middle and max of the pinch control

Look at this thread http://www.diystompboxes.com/smfforum/index.php?topic=112217.msg1037302#msg1037302

The circuit is sensitive to transistors beta/hfe, any 2n3904 might not work.
The transistors need to be selected for this circuit to work correctly