[robjrock]

Ok, first of all, I swear I've searched everywhere for an answer, google, head-fi, etc etc and I haven't been able to find one. Also, apologies for the noob question. But I'm about to order some parts and I basically need one thing answered, I'm hoping the HF community can help me...

Metalised Polypropylene Caps: Are they as good / better than using polypropylene film or metalised polyester caps for C2 in the standard Cmoy design? (ie 0.1uf caps ~ Part Lists and Suggestions ) - I understand standard polyester film caps are a step down.

Basically this one website in the UK has everything except the recommended C2 caps and I really don't want the expense / minimum order hassles of ordering two measly caps by themselves! Thanks guys!

 

[Pars]

I would think that the metalized polypropylene would sound better than the met. polyester. Whether or not they would be up to polypropylene I wouldn't know. If your source(s) do not have any DC offset, you could build it with no input caps... no cap is better than any cap

 

[NelsonVandal]

Are you really sure you need C2 at all? I think probably not. Remove it and stop worrying about capacitor quality

 

[NelsonVandal]

Quote:

Originally Posted by Horse /img/forum/go_quote.gif The limits of a CMOY don't really lie in C2. The metallized polypropylenes are perfect.

No they're unnecessary. They're large, cost money and can do nothing but degrade the sound.

 

[Earwax]

I wouldn't automatically dismiss metal polyester. I have used the Vishay MKT1818 and MKT1817 series and they seem to be entirely neutral. MKT1818447064 Vishay/Roederstein Metallized Polyester Film Capacitors 0.47uF 63V 5%

I've built amps with input caps and then removed them and not heard a difference.

(OTOH, I've tried mylar caps and they sounded horrible)

 

[robjrock]

Thanks for your replies, greatly appreciated. I think I'll go ahead and order a couple, but I didn't even realise you could bypass them all together. Guess I'll give both methods a try. Cheers y'all!

 

[robjrock]

Well in case anyone is interested I ended up using two X2 metallized polypropylene caps because I was too worried about DC offset killing my precious Phonak PFE earphones! But to my ears it sounds brilliant: not saying you can't do better, or it wouldn't say better just left out altogether, and I haven't actually tested any other caps, but to me they sound just dandy.

Oh, and they are quite large, which goes with the vague idea I read here or there that suggests 'bigger is better' when it comes to caps (physically bigger I mean)

I do have a couple of small plain polyester caps lying around, may slip them in one day to compare the SQ (which I imagine would be worse!) But for now I'm too busy enjoying my Cmoy...!

 

[hopeless]

I'm very happy with the Wima MKS 2 for my DAC's (4.7uF 63V).

 

[Tomo]

Hey,

I am baaaack. Now that is done. ...

I think MKP (metalized polypropylene) would be just fine; in fact, preferable. Any film/foil is said to be better, but they are too big. Rob, you said your metalized polypropylene cap is too big, ... just wait until you see my Teflon Film/Foil 1uF cap. It is as big as your common "C" battery. I also have OrangeDrop caps and they are bigger than your AAA battery. Unless your chasis is bigger than common removable harddrive cases, you are better off using MKPs.

(Polyester, Mylar, and Carbonate can also be used with good results. It is said that Polypropylene is better because it works nice in audible frequencies. But for me, I had good results with polyester, too.)

If you are concerned with sound quality. It is generally better to go for higher voltage capacitors. So, in average, going for 630V Solen would be somewhat better than 250V Solen. (The C battery sized teflon cap is 1000V!) However, note higher voltage stuff is generally bigger too. (Polyester and Carnonate run at fairly lower voltage.)

T

 

[robjrock]

Quote:

Originally Posted by Tomo /img/forum/go_quote.gif Rob, you said your metalized polypropylene cap is too big, ... just wait until you see my Teflon Film/Foil 1uF cap. It is as big as your common "C" battery.

LOL: yep, I know they can get pretty huge, I wanted everything to be 'portable' enough... I guess in retrospect they ain't that big! I would like to build a desk-top cmoy (or maybe PPAv2) and use components like big caps etc for the best SQ

Thanks for your info, its re-assuring to know I haven't used the worse caps in the world...

 

[Tomo]

Hey,

I am doing exactly what you said. Building a desktop CMOY amp. You saw my re-education thread.

Anyways, look at these caps.

Guess which one is my favorite. I think I lost my teflon cap some place

I can't find em.

T

 

[Fred_fred2004]

use the energiser

 

[BrianDonegan]

A couple points:

More important then the material (polyester [MKT] vs. polprop [MKP]), is the construction of the cap. Stacked film is generally better than wound film construction. this is because wound film results in induction, where stacked film does not (think coil of wire vs flat wire). Stacked film caps also have lower ESR, which is good for inline applications such as DC-blocking.

I am not saying MKT vs MKP is not a consideration, just not the only one.

Also, Mylar is a 3M brand name for polyester... mylar caps are polyester caps.

 

[diditmyself]

You still don't need them in a CMOY with "normal" modern bipolar input or JFET input opamps. It's just fetishism.

 

[hopeless]

Except that if the source has a little bit of DC offset...

In that case, the input DC blocking caps might even improve the sound, besides obviously keeping your headphones safe.