Wima capacitors for audio?

[Analog_Fan]

Polyethylene Terephthalate (PET)
or Polyester?

i believe, i have read Wima recommends "Polyethylene" for audio.



What about Polyester?

sifting through the mouser catalog.

 

[Ricardus]

It's fine.

 

[john12ax7]

Wima polypropylene is very standard in a lot of audio gear. It's a better dielectric than polyester.

Edit: I was thinking of something else regarding PET.

 

[soapfoot]

PET/Mylar/Polyester are all different names for the same type of plastic film.

they’re just fine for audio.

polypropylene is slightly better on paper, and usually available (sometimes slightly larger, and harder to metallize).

polystyrene is a good dielectric but is prone to overheating and is rarer today, especially in larger values.

Polytetrafluoroethylene (Teflon) is very good, but rare, quite expensive, and overkill for most applications.

polycarbonate, polyphenylene sulfide are other good dielectrics. Really, audio is pretty easy.

I usually look for film and foil first over metallized films, but metallized films can work just fine

 

[Analog_Fan]

Yeah, i also believed after reading that polypropylene where the sacred ones.

I have made a few voltage controlled filters with em and they sound very good, as far as i can tel.
That's why i want them, i aim for the 2.5% variants else 5%.
I like their red packages, sticks out on the PCB's, in the past i have used those from Siemens (grey), not sure if they still are being sold.
I have a ribbon with a few blue ones, not sure what brand, but look the same as Wima package wise.

There are a lot or Wima's at mouser, it's easy to order the wrong one, psychical size.

Roland used green capacitors in their TB-303, TR-606, System 100(m) and so.
Believe these are polyester or polystyrene or so, look like handmade.

Now i found those from Xicoh.

 

[Analog_Fan]

Didn't know that TDK produces capacitors as well.

datasheet: TDK FG series, TDF FA series

Would you include or view them as suitable these in a equalizer circuit, audio path.
2.5 mm x 5 mm
those Xicon are rather big atleast 12 mm x 5, using 4 of them would require almost require a extra pcb (in my case).

 

[soapfoot]

In an equalizer, space permitting, I’d personally probably choose either polypropylene or polystyrene, film-and-foil.

many other things would work well, but that’s what I’d choose if I wanted to tell myself I’d chosen “the best”

Most likely any difference in performance would be very slight or even negligible

brand name would be far, far down my list of priorities. Dielectric material and construction are most important.

 

[JohnRoberts]

Didn't know that TDK produces capacitors as well.

datasheet: TDK FG series, TDF FA series

Would you include or view them as suitable these in a equalizer circuit, audio path.
2.5 mm x 5 mm
those Xicon are rather big atleast 12 mm x 5, using 4 of them would require almost require a extra pcb (in my case).

COG (NPO) dielectric are very neutral so fine for audio paths.

JR

 

[soapfoot]

Yes, C0G (class 1 ceramics) are among the very best performers by all objective metrics, but can be pretty difficult to source in values over 100nF or so.

Recently you'll find them as high as 470nF sometimes for workable prices, but only at low voltage ratings. You probably won't find higher values than that (at least not in sensible form factors or prices).

When searching, make sure you enter C0G (C-zero-G) or NP0 (n-p-zero), not the letter "o"

Also worth noting that these are a very different matter from the more common "class 2" ceramics, which are generally not indicated for high-performance signal-carrying applications.

 

[abbey road d enfer]

Didn't know that TDK produces capacitors as well.

datasheet: TDK FG series, TDF FA series

Would you include or view them as suitable these in a equalizer circuit, audio path.

These caps are ceramic. Only the COG are suitable for "being in the signal path", so only up to 10nF.
The others have too much capacitance variation with applied voltage, making them distortion generators.

 

[scott2000]

Those green wima (fkp?) were nice.

 

[Analog_Fan]

Those green wima (fkp?) were nice.

Ya, but my supplier (a litle mayor trader) found that's it good enough and hang his coat definitely on the hanger and went to enjoy his pension.
i got those green from him.

don't discover those at mouser.

 

[Analog_Fan]

These caps are ceramic. Only the COG are suitable for "being in the signal path", so only up to 10nF.
The others have too much capacitance variation with applied voltage, making them distortion generators.

the E.Q. circuit i got uses one 470pF and one 560pF.

COG never heard of that before.

it's seems watching for low tolerance is not enough, i was happy to find 5% TDK's, guess ...

thank you guys.

 

[soapfoot]

Tolerance is definitely not enough information.

As Abbey said, class 2 ceramics have high voltage and temperature coefficients—the former of which can generate measurable harmonic distortion, and the latter of which can make the exact value in-situ temperature dependent.

class 1 ceramics (C0G, NP0) on the other hand are exceptional performers in these regards.

For 470pF and 560pF, C0G ceramics would be an excellent choice, and would probably be my preferred choice (polystyrene film would also be excellent)

 

[CJ]

noise can be an issue with the really flat WIMA caps from yesteryear, circular caps seem to cancel noise, i noticed this while building a Pultec EQP1a

ceramics can be microphonic due to their crystalline nature.

 

[Gold]

In the EQ circuits I have experience with the brand of like material capacitors matters. In the Igor Sontec TDK PP caps sounded much better than Wima mkp or fkp.

 

[Ivan K.]

Capacitors are often "opinion-land" as opposed to fact based. See article below. Application is very important too. Polypropylene and all ceramic caps are piezoelectric, so if they are on a PCB inside a subwoofer, you may get PIM (passive intermodulation distortion) products, but in a mic pre, they would be fine. I'd recommend looking at the classic Cyril Bateman Wireless World & follow-up articles here: Cyril Bateman's Capacitor Sound articles | Linear Audio NL.

Those green, polyester caps are the cheapest of the cheap and I don't have any great love for them. All things being equal (and never are), PP are lower distortion than any of the polyesters. Also, using a higher voltage than needed (as in 2X or more) caps also will give you lower THD. Now, I'll have to re-read the articles to see if my memory needs a good demagnetizing and rerecording!

 

[JohnRoberts]

Capacitors are often "opinion-land" as opposed to fact based. See article below. Application is very important too. Polypropylene and all ceramic caps are piezoelectric, so if they are on a PCB inside a subwoofer, you may get PIM (passive intermodulation distortion) products, but in a mic pre, they would be fine. I'd recommend looking at the classic Cyril Bateman Wireless World & follow-up articles here: Cyril Bateman's Capacitor Sound articles | Linear Audio NL.

Those green, polyester caps are the cheapest of the cheap and I don't have any great love for them. All things being equal (and never are), PP are lower distortion than any of the polyesters. Also, using a higher voltage than needed (as in 2X or more) caps also will give you lower THD. Now, I'll have to re-read the articles to see if my memory needs a good demagnetizing and rerecording!

there are objective metrics that describe capacitor behavior adequately. I first wrote about them back in the 80s.

COG/NPO caps are quite good.

Polyesters are not the cheapest and not the worst.

JR

 

[john12ax7]

In the EQ circuits I have experience with the brand of like material capacitors matters. In the Igor Sontec TDK PP caps sounded much better than Wima mkp or fkp.

Careful Paul, the double blind ABX police will be coming for you soon.

I too have also heard caps sound different.

 

[living sounds]

Those green, polyester caps are the cheapest of the cheap and I don't have any great love for them.

Yes, but in a drum machine or synth higher distortion might be a good thing.