advertisement


Capacitor Types Explained

jagdesign

pfm Member
Does anyone have a good overview of the different types of capacitors, where they are typically used in audio applications, and why one should choose one type or brand over another?

Hoping this might be a useful reference for others as well as myself :)
 
There are plenty of such guides already extant but the really important point is that this is of generally much less importance than people think.
As I've already posted elsewhere today, an excellent circuit built with second hand parts from old TV's and video's etc will still sound excellent but an average or below circuit built with the most expensive boutique parts will still be average or below. I would say the difference made by the quality of the parts is only maybe 2%!! Layout probably 10% ish and the rest is down to circuit topology.
 
There are plenty of such guides already extant but the really important point is that this is of generally much less importance than people think.
As I've already posted elsewhere today, an excellent circuit built with second hand parts from old TV's and video's etc will still sound excellent but an average or below circuit built with the most expensive boutique parts will still be average or below. I would say the difference made by the quality of the parts is only maybe 2%!! Layout probably 10% ish and the rest is down to circuit topology.

Interesting - so other than using electrolytics for power supply duties, due to their ripple current handling abilities, it’s pretty much free reign on the other types in other areas, so long as the specs are correct?

Presumably, a tighter tolerance is nearly always desirable?
 
I only kn
Interesting - so other than using electrolytics for power supply duties, due to their ripple current handling abilities, it’s pretty much free reign on the other types in other areas, so long as the specs are correct?

Presumably, a tighter tolerance is nearly always desirable?
Oh, and pay attention to whether you need polarised or non-polarised capacitors.
 
After playing around a fair bit my view is don’t assume you know better than the original designer and just replace any tired ones like-for-like with the best quality of the same type you can find, e.g. replace PIO with PIO, electrolytic with electrolytic and film with film. Anyone who tells you they all sound the same is deaf as a post and should be ignored! As documented on my JR149 thread I have two identical sets of crossover boards so can swap in/out very easily (plug-connector) and I spent some time comparing modern film caps to electrolytics (the original spec). It changed the voicing to a substantial extent, and certainly not for the better. I’ve heard exactly the same in electronics. This is not that film caps are worse, they are clearly better in pretty much every measurable way, it is that the speaker was designed and voiced using electrolytics.

Really good kit, i.e. the stuff you buy because you like the way it sounds against other options, has obviously been voiced by the manufacturer using the components that are in it. Change them at your peril, e.g. changing tantalum caps in a Naim preamp unquestionably changes the voicing, they are a big part of the sound you bought, same with changing PIOs to modern film caps in a vintage Quad, Leak, vintage Fender guitar amp or whatever. Once you do that you are way, way out on your own, it is no longer the product you bought, it is now a different thing.

Sure, some folk love tweaking and changing stuff, but to my mind it is too much of a crap shoot, far better to buy something you really love and just maintain it properly so it retains the sound you paid good money for. I’m also now very firmly of the mindset that if you do want to alter something ‘to taste’ you absolutely need two of it; one to keep entirely stock as a reference point, the other to modify. It is just way too easy to persuade yourself something is an improvement whereas on long-term re-evaluation against the reference unit it proves otherwise.
 
@Tony L definitely agree with your sentiment of respecting the designers decisions (in most cases).

Interestingly it’s a small tweak on my Quad 34 , to reduce the effects of the rumble filter in the phono stage, which sparked this discussion, and I believe this is a tweak that you very much advocated :)

@martin clark has very kindly donated me some Wima (polystyrene?) caps to do the mod, but I also have some Nichicon electrolytics which are the correct values. So just trying to understand why most people would recommend the Wima’s over something else for this application.
 
Interestingly it’s a small tweak on my Quad 34 , to reduce the effects of the rumble filter in the phono stage, which sparked this discussion, and I believe this is a tweak that you very much advocated :)

Yes, definitely. Rob did mine, so I’ve no idea what he used, though the combination of reducing the rumble filter and setting the loading for the Ortofon 2M Black I was using absolutely transformed it from something I’d not want to listen to at all to a phono stage I actually preferred with that cart to an EAR834P! I guess Quad designed it rather aggressively so as not to send a load of warp frequencies into ESLs. With the Tannoys the rumble filter just sat on bass dynamics, it just came to life afterwards. IIRC Rob dramatically reduced its effect rather than remove it entirely. He also recapped the whole preamp (Panasonic electrolytics IIRC).
 
each cap type has a specific function where it will offer better measured performance vs alternatives, but pricing plays a role in choice for manufacture as well so its seldom clear cut and 'good enough' often suffices
 
They pretty much all sound the same but there are plenty of people with lively imaginations who wrongly claim they all sound different.
There are a few very specific applications where they can be quite critical, which I will keep to myself, but other than that....

I suggest those that think they sound different rig up a little jig so they can add a capacitor to the signal path between pre and power and then judge for themselves.
 
Does anyone have a good overview of the different types of capacitors, where they are typically used in audio applications, and why one should choose one type or brand over another?

Hoping this might be a useful reference for others as well as myself :)

I think the first part of the op question is where and why you would use a certain type of capacitor in a circuit e.g. film, Tantalum, electrolytic, SAL, low leakage, high ripple, low/high impermanence, high Value, small package etc.
But it looks like everyone has just jumped on the "all capacitors sound the same" band wagon ? yawn
Alan
 
All in all the only cap types needed are electrolytic, polypropylene and polystyrene. For ALL jobs in audio one of those types will be the best you can get. Electrolytics are of course poor but when you need loads of capacitance in a manageable size they are your only choice. Polystyrene are generally for use in small values of up to 10nF and have a significant crossover with polypropylene but polystyrene will be what you usually use for values under 1000pF, polypropylene can then take you up to 1uF or a bit more (I often use 4.7uF and even 10uF polypropylene for critical uses), and electrolytic up from there.
The ones to be avoided at all costs are high K ceramics. To keep it simple, don't use a ceramic cap of over 1000pF/1nF in the signal path.
I don't use tantalum as they are nasty things with high distortion and likely to fail as a dead short circuit. If you must use them then never apply a DC voltage in excess of half their rated value.
Paper in oil (PIO) I also never use at all. They are used in similar values and apps as polypropylene but polypropylene are VASTLY better in every way so there is no good reason to use PIO. They are an anachronism that some who believe that everything from before 1970 was better than modern stuff wrongly believe to offer something special...
They can also be quite unreliable depending on how good the seals are as they can take in moisture and become leaky.
The other main types are mylar/polyester and polycarbonate and these can offer good performance but polypropylene is even better.
 
Last edited:
COG, cough cough.

Precisely why I said not to use ceramic over 1000pF.... C0G (AKA NP0) are available up to around this value. They are fine where low value caps are needed and are cheap but polystyrene can be regarded as even better.

Teflon are also extremely good but very expensive indeed and probably add nothing to the party beyond what polyprop can do..
 


advertisement


Back
Top