Sandspar Fuzz - hissing/fizzling at high fuzz levels

[Coach_McGuirk]

I've tried a few different transistors, but I'm getting similar issues with my Sandspar Fuzz (silicon fuzzface) making some interesting noises when the fuzz is cranked up to max. At first I thought it sounded kind of cool, like a broken record, but I'm trying to figure out how to make it go away. Changing transistors doesn't seem to matter. Obviously, I've played with the trim pots too. I have the Q2 C bias set around 6V, but it doesn't matter where I set the bias. The issue persists.

 

[harmaes]

It can help if you reduce the clean input trim a little, this should remove the oscillation.
Thinking about it, silicon transistors shouldn’t oscillate as much as germaniums. Validate all components to see if everything is correct. Otherwise share some pics so we can validate as well.

I wire all the Sandspur and Sunflower builds with an external clean input trim to remove some of the wooly low end and/or to reduce oscillation. Also helps to dial it in to different guitars. Reducing the fuzz a little will also work but might not be the sound you’re after.

Did you box the build already or is this outside of the enclosure? Also the bias trimpot is most convenient to set to 4,5V when the bias pot is in the middle. Then you can get to 6v+ for a fatter sound and below 3V to have some more splatty/spitty sounds.

 

[Coach_McGuirk]

Yeah, I think there's something wrong because I don't really hear the same sound in demos I've listened to.

I should note that I'm using bc549c right now, but I've cycled through a few. I don't have any BC108, so I have to try other ones.

 

[harmaes]

Yeah, I think there's something wrong because I don't really hear the same sound in demos I've listened to.

I should note that I'm using bc549c right now, but I've cycled through a few. I don't have any BC108, so I have to try other ones.

you can use a lot of silicon transistors, as long as you check the pinout. I prefer BC183C