Enchanted Boost Input Cap Question

[falco_femoralis]

Hi all, I'm learning more about circuit design. I noticed the Enchanted Boost doesn't use an electrolytic decoupling input cap, rather a standard film type. Is the electrolytic not necessary? I thought it was prudent to filter DC before the transistor.

Thanks

 

[GAStan]

The decoupling cap  isolates DC and depending on uF value can filter certain audio AC frequencies.

Type of cap (electrolytic, film, ceramic...) can (depending on who you talk to) effect tone.

Edit: capacitor types can be interchanged as long as value and voltage ranges are adhered to. Different types do have other characteristics (look at these on the individual listings on vendor sites such as Mouser or Digikey or look at spec sheets) that will affect how it interacts with the circuit it is used in. For decoupling as used in our pedals value, voltage rating and physical size/shape are probably the most important. You can socket this and try various types to see if there is any audible difference and if so which one you prefer. You can also try different value to see how this impacts the sound.

 

[falco_femoralis]

^ does the decoupling cap need to be electrolytic?

 

[GAStan]

No

 

[GAStan]

If you haven't already see edit to my first post

 

[lowpitch]

If we're talking about C1, that's a coupling capacitor, not a decoupling capacitor. It blocks DC while allowing AC signals to pass. A decoupling capacitor would be connected in parallel to ground, and for example be used to filter out high frequencies or stabilize voltages in the power supply. Neither needs to be electrolytic. In fact, ignoring cost and size, there aren't a lot of cases where electrolytic capacitors would be preferrable over film capacitors.