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Capacitor sizing

Started by SprinkleSpraycan, December 25, 2021, 06:31:05 AM

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SprinkleSpraycan

Today I was building a buffer for my pedal chain and was short the 10uF Audio Capacitor that was called for. I used a 100uF Capacitor instead to finish up the build and it seems to work fine. Can someone tell me what difference this will make? Thanks

GibsonGM

If you post a schematic, I'm sure we can!  ;)      In general, an input cap works with the input impedance of the device following it, forming a high pass filter.  The frequency this filter passes is determined by the impedance AND the capacitance. A larger cap will result in more bass content being 'allowed' into the circuit.  Sometimes this is desirable, and other times it's not, depending on what you're doing with the circuit.   So, a 10x larger cap may be just fine, but will increase the bass content.
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duck_arse

I feel sick.

GibsonGM

Yes, Sprinkle - welcome!  :) 
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MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

SprinkleSpraycan

#4
Oh man I meant to post what I was working off and forgot. Oops. https://guitarpedalparts.com/products/buffer-pcb
I don't have a schematic. Just this page, which is what I ordered.
Thanks for the input and warm welcome. I'm new to building and learning new stuff everyday.

GibsonGM

Yes, it's just allowing more bass in. Maybe some time, if you enjoy building, you'll get some more parts, and can just pop in the 10u (or smaller!)   :)   If it's not bothering you tone-wise, it's not a problem...what is your next build?
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MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

iainpunk

Quote from: GibsonGM on December 25, 2021, 09:52:46 AM
Yes, it's just allowing more bass in. Maybe some time, if you enjoy building, you'll get some more parts, and can just pop in the 10u (or smaller!)   :)   If it's not bothering you tone-wise, it's not a problem...what is your next build?
its an output capacitor, for a buffer, i think everything over 1uF should be plenty large for a buffer.

welcome to the forum and cheers!
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers

GibsonGM

Why did I think it was an input cap?  :icon_eek:   Same difference.  :icon_lol:
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MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

SprinkleSpraycan

Quote from: GibsonGM on December 25, 2021, 09:52:46 AM
Yes, it's just allowing more bass in. Maybe some time, if you enjoy building, you'll get some more parts, and can just pop in the 10u (or smaller!)   :)   If it's not bothering you tone-wise, it's not a problem...what is your next build?

The other build this weekend was modding a ds1 to the jhs synth mod. Super successful. Also built a silver pony 2 but one of the chips blew (fairly sure it was bad out of box). When I get home from the family's house I can get more chips and finish that one up.
When I post pictures to my Instagram I'll link it here.


GibsonGM

What's the mod SOUND like?  :)
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MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

SprinkleSpraycan

If you swipe on the IG picture there is a video. 

duck_arse

I feel sick.

fryingpan

#13
Generally speaking, those very large valued caps are intended to block DC, and don't have a sound sculpting purpose. You can use whatever sized cap over the specified value, usually, with no ill effect. In fact, if you use electrolytics, a good practice is to use ten times the specified value (of course only if the specified cap is unpolarized, generally speaking a poly cap; if the design already calls for an electrolytic, then just use what the schematic specifies). If a circuit specifies a 1uF poly, for instance, and it mostly has a DC blocking purpose, use a 10uF electrolytic. This way, you'll ensure that the reduction in capacitance due to cap aging (which is a real thing with electrolytics) won't skew the frequency response, and also keeps the frequency range where the electrolytic cap might add distortion far from the hearing range (dropping it to, say, the 1-5Hz range). Same thing applies for bypass caps on transistor sources/emitters, *provided* the bypass cap is not intended to provide a treble boost. For instance, if you see a 68uF cap from source/emitter to ground, you can use 100uF, 150uF, whatever. If it's a smaller-valued cap it's bound to be a low cut, and you should really use polyester caps there if possible (for guitar, it might not matter though).