So I'm designing a circuit at the moment that's based on a big muff. I feel like it has some unnecessary polar electrolytic caps that are taking up space. How do I know what caps need to be polar electrolytic and which can be non polar box caps?
Posted Sep 5, 2023, 11:36 PM UTC
Most muffs only have an electro as the power filter cap. Are you using an odd Muff schem?
It's the swollen pickle.
It's always ok to replace a polarized cap with a non polar cap. The polarization of electrolytic caps doesn't do anything useful-it's just a side effect of how they're made.
This. You can use a big ass 100uF film cap as a power supply filter cap if you want, but it'll just be huuuuge. Hence electrolytics.
Thanks for the help. Think I'll replace all the electrolytics in the signal path with box caps and then leave the ones in the power section as electrolytic. Think some of this issue may just be reading the schematic wrong / assuming caps are electrolytic / polar when they aren't .
You’ve already gotten your answer, which is that you should use non polar box caps in the signal path and polar electrolytic caps for power. I want to flesh out some details.
Electrolytic capacitors should be avoided as much as possible in the signal path for a few reasons. First, they have much looser tolerances than other types, meaning that you’re more likely to get a very different value than you expect. Therefore you should never use them to set a time constant. Second, they are much noisier. This becomes less noticeable with larger values, but it would be noticeable if you were to use exclusively electrolytics. The only exception is if you need something like a 10uF or larger. At that point you’d be hard pressed to find a film capacitor that big and you’re letting all the AC signal through so the exact value isn’t so important.
Thanks. That's super helpful.
I think it'll naturally shake out depending on the capacitance of the capacitor. Electrolytics are likely used where film would get physically too large to supply a certain capacitance value.
Yeh I noticed anything 1uF or above was using electrolytics. But there was only 4 that were above 1u so I changed all the 1u to box caps and kept the other 4 as electrolytics.
Early big muffs used nearly all ceramics. Don't sweat the type. They make little to no difference in this circuit. Values matter most.
Where in the schematic are you referring, if it's at the beginning it's because most fuzz don't get fuzzy without a pretty big I put cap, you can take the bottom out of the output by using the decoupling cap and the output put as a high pass filter