Does Capacitor Type Matter

[drewsmith83]

Building the Dwarven Hammer right now and noticed that most folks use box type capacitors for most of the assembled boards I’ve seen. I’m assuming this is primarily for space on the board but since the build instructions didn’t specify I planned on using ceramic capacitors as they seem to last longer. Maybe this is a dumb question but for non polarized capacitors would it really matter if it’s box or ceramic?

 

[steviejr92]

Building the Dwarven Hammer right now and noticed that most folks use box type capacitors for most of the assembled boards I’ve seen. I’m assuming this is primarily for space on the board but since the build instructions didn’t specify I planned on using ceramic capacitors as they seem to last longer. Maybe this is a dumb question but for non polarized capacitors would it really matter if it’s box or ceramic?

Either will do. MLCC caps are usually in the pF and box film caps are usually in nF. There are exceptions with certain values like a 1uf can be box film or electrolytic.

 

[drewsmith83]

Either will do. MLCC caps are usually in the pF and box film caps are usually in nF. There are exceptions with certain values like a 1uf can be box film or electrolytic.

Ah that makes some sense. I was using 0.047uF for a 47n (e.g.). I guess I missed the memo the unit is a way to delineate. Thanks.

 

[steviejr92]

Yeah careful that .0047uf is actually reading 4.7nF not 47nf. No problem glad that helped!

 

[drewsmith83]

Yeah I edited my typo. Good catch. This is not my day job lol.

 

[steviejr92]

What are you building if you dont mind me asking?

EDIT: duh the dwarven hammer!

 

[drewsmith83]

Yep the hammer but I have a few boards on deck

 

[steviejr92]

Yep the hammer but I have a few boards on deck

Looking forward to seeing the build reports!

 

[Snicksound]

Either will do. MLCC caps are usually in the pF and box film caps are usually in nF. There are exceptions with certain values like a 1uf can be box film or electrolytic.

Box are typically film caps (polyester or polypropylene), but not all film caps are box.

You also have the "red drop" types and other rounded caps.

But yeah the box type (e.g. Wima) make for cleaner boards.

 

[steviejr92]

Box are typically film caps (polyester or polypropylene), but not all film caps are box.

You also have the "red drop" types and other rounded caps.

But yeah the box type (e.g. Wima) make for cleaner boards.

I like the way these look but for size reasons and footprint spacing i use the regular box film caps! Darn now i want to use these style caps for my next build

 

[DAJE]

View attachment 40077

I like the way these look but for size reasons and footprint spacing i use the regular box film caps! Darn now i want to use these style caps for my next build

I use them: three greens and a red in my last build report, the Basstaur.

 

[steviejr92]

I love how they look! I used them on my Mountain Oyster boost!

I use them: three greens and a red in my last build report, the Basstaur.

 

[DAJE]

I love how they look! I used them on my Mountain Oyster boost!

Yeah, they're cool. I have a heap of green caps in pf sizes, 220pf to 820pf, so they get used pretty regularly.

 

[steviejr92]

Yeah, they're cool. I have a heap of green caps in pf sizes, 220pf to 820pf, so they get used pretty regularly.

Funny i do too i just havent been using them idk why.

 

[Alan W]

Building the Dwarven Hammer right now and noticed that most folks use box type capacitors for most of the assembled boards I’ve seen. I’m assuming this is primarily for space on the board but since the build instructions didn’t specify I planned on using ceramic capacitors as they seem to last longer. Maybe this is a dumb question but for non polarized capacitors would it really matter if it’s box or ceramic?

Have you had failures from film caps? (Just curious.)

 

[Bricksnbeatles]

you don’t want to use MLCCs anywhere that dc is present iirc

 

[benny_profane]

you don’t want to use MLCCs anywhere that dc is present iirc

They are typically fine for decoupling, but yeah, capacitance is not stable across dc bias variance (for dialectrics other than C0G (NP0)).

 

[Chuck D. Bones]

MLCCs are ok, but ceramic caps can be microphonic and the low voltage ceramic caps (<100V) have long-term reliability problems because the dielectric layers are so thin. The DC bias issue doesn't really come into play at the low voltages we find in pedals. Ceramic caps do not last longer than film caps. Except for aluminum electrolytics*, the two main causes of capacitor failure are manufacturing defects and overstress. Keep the stress levels low and a film cap will outlive you.

*Aluminum electrolytics have a finite lifetime because the electrolyte will eventually dry up or eat thru the insulation layers.