BIG Film caps and Noise

[Deleted]

There is an interesting thread in DiyAudio ( with measurements) of the effect on big film caps, by noise from PSU etc.
Perhaps those big Russkies, with their metal cases, may benefit ftom their cases being earthed ?
SandyK

www.diyaudio.com/forums/showthread.php?s=&postid=1481918#post1481918

[Deleted]

More on Capacitors and other interesting associated subjects
from Walt Jung etc. (fairly technical stuff)

waltjung.org/Classic_Articles.html

[charleyphogg]

Nice one SandyK

Someting else I found there proves, to me, the argument towards different cables and why they would make a difference.
Even for those who can't do the math, I certainly cant even bother trying wiht it any more, but it is there in balck and white.

Here's the linkk.....

en.wikipedia.org/wiki/Skin_effect

Even way back then, they mention the direction of flow,i.e. the reason IC's are marked with am arrow.
Hope this didnt take it off topic, I think it still applies. I mean, really, in a nutshell, the only diffence between an IC and a cap, is that the ic doesnt store the energy. Doesn't everything else, basically apply?

[Deleted]

charleyphogg
It is now widely accepted that "skin effect" is of little consequence at Audio frequencies.
It does however play a part at radio frequencies. These days you see valve amplifiers with thick insulated wire being nicely routed via 90 degree bends etc to look good. Years ago these wires were direct between stages, without bends, particularly in radios etc. They don't need to do this with audio, or use silver plated wire like they do with R.F.

SandyK

[charleyphogg]

Thanks for setting me straight .

[rickcr42]

there is also the microphonic aspect of audio coupling capacitors.I realise we don't listen to tapping erasers but music through our gear but it CAN be a bit unsettling to tap a cap lightly with a pencil eraser and here it reproduced via the loudspeakers or headphones !

My understanding is (and it makes good sense on a strictly mechanical/vibrational/acoustical level) is that the more voids there are inside the capacitor housing the more microphonic the cap will be while the tighter the dielectric is wrapped and the tighter the cover is the less will be the effect.

moving to a more practical example: ever notice how HEAVY for their size the more musical sounding film caps are ?

[Deleted]

..... while the tighter the dielectric is wrapped and the tighter the cover is the less will be the effect.

So where does this leave the gentle art of "skinning" capacitors, as proposed recently ?

[rickcr42]

Nekkid Capacitors ?

SHOCKING !

[rickcr42]

..............but makes sense also when you consider the cover is also a dielectric so will have an effect on the sound and even if it did not (called CYA :Cover Your Ass by pacifying both camps ) we audiophile DIY nut jobs have to have SOMETHING to do because as we all know we just can't leave shit alone even IF it blows the "circuit designing by pretty color combos" theory all to hell


if there is any merit to the "strip the bitch" technique I can not personally say but I can say from a position of personal experience there are SQ gains to be had from strapping and dfamping larger caps and this goes for PTP construction as well where it is my personal practice to use tie strip to crank those suckers down right to the terminal strip mounting point and even more weirdly (I AM the rickmonster after all ) never leave Dangly Wires feeling what is good for the caps MUST be good for the wires they being a potential dielectric as well unless they too are stripped nekked

[Deleted]

(called CYA :Cover Your Ass by pacifying both camps )

Bummer! And here was me trying to get you and Mike sparring with each other !

[PinkFloyd]

Both Leo and myself are in agreement that skinning electrolytics "does" have an audible effect... whether that effect is for the good or not is totally down to personal taste.... I feel that also grounding the electrolytic enclosures brings about sonic improvements.... Leo has replicated my string and sellotape grounding technique in his SOLO and he also found an audible improvement.

There is certainly a lot more to a cap than slotting it in and cranking down the lid. If you have a bank of, let's say, 10 caps you can flood hot melt glue in between them and this has an audible effect....... hot glue damping example:





You can also add felt pads to the top (as shown in the above picture) My latest "favourite" it to apply a blob of sticky bitumen "under" the cap.... seems to tighten the bass up a tad. Of course there are many combos and only your ears will decide what's right for you.

Strip them bare, ground them, glue them, bitumen them, blu tack them, felt pad them.... do the lot, do one or do two.... plenty of fun to be had. My last idea was to skin an electrolytic, lightly sand it with some 1000 grade wet or dry paper and then apply some damar varnish.... possibly 5 coats..... leave for a good few weeks to cure and then fire them into a circuit..... I haven't had the time to try this as yet but certainly will be giving it a go!

All good stuff and all cheap to try too

[PinkFloyd]

Apr 17, 2008 0:41:20 GMT rickcr42 said:

it CAN be a bit unsettling to tap a cap lightly with a pencil eraser and here it reproduced via the loudspeakers or headphones !

Why are you tapping caps with a pencil eraser you woman's blouse? Use your finger! you frightened incase you get a shock or something? Pencil eraser my royal arse!

[leo]

I tried the Ruskies as signal coupling caps, had them running in since last night, they are on the output of my dac to allow easy swapping etc.

My first impressions are totally different to what I was expecting ;D
I was expecting bright and thin, how wrong can somebody be!!! these caps are extremely detailed and smooth , very nice tbh and don't sound anything like other polystyrene caps I've tried before.
Grounding the case on these lowers background noise making silences blacker, gives a wider soundstage

Thanks to Mike for letting me try these8-)

[jonclancy]

I think I missed this, but what were the caps please, mate?

I have the teflons about to go into the Pearl as a bypass to 6u8, and I'm very interested to hear what you got out of the Ruskies.

Cheers

Jon

[leo]

Apr 17, 2008 21:51:32 GMT jonclancy said:

I think I missed this, but what were the caps please, mate?

I have the teflons about to go into the Pearl as a bypass to 6u8, and I'm very interested to hear what you got out of the Ruskies.

Cheers

Jon

Mike was kind enough to send me a couple of 0.47uf polystyrenes , I used them on the Elcheapo dac output first just to try out.
0.47uf is a little low here and theres some slight loss of low end but its fine for testing.

I'm going to try bypassing with those 0.1uf teflons next

[leo]

BTW those teflons should make a very fine bypass across the 6.8ufs

[Deleted]

I'm going to try bypassing with those 0.1uf teflons next

Leo
I hope you mean bypassing capacitors like >100uF electros ?
Alex

[rickcr42]

Apr 17, 2008 17:08:37 GMT PinkFloyd said:

Apr 17, 2008 0:41:20 GMT rickcr42 said:

it CAN be a bit unsettling to tap a cap lightly with a pencil eraser and here it reproduced via the loudspeakers or headphones !

Why are you tapping caps with a pencil eraser you woman's blouse? Use your finger! you frightened incase you get a shock or something? Pencil eraser my royal arse!

Hammer was on loan compadre