Off Topic Q: High Ripple Current in cap.

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SamL

Off Topic Q: High Ripple Current in cap.
« on: 16 Jun 2004, 04:32 am »
Saw the new Panasonic FM cap over Digikey catalog (page 778).

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FEATURES:
• Low Impedance: 40-70% lower than FC Series • High Ripple Current: 50% higher than FC Series • Long Life: 2000 ~ 7000 hours at +105°C • PVC free, Pb free • Appearance: Black body with gold markings
*

Is high ripple current a good thing in cap? Is this mean the Panasonic FM cap is better than FC?

TIA,
Sam

Occam

Re: Off Topic Q: High Ripple Current in cap.
« Reply #1 on: 16 Jun 2004, 04:21 pm »
Quote from: SamL

FEATURES:
........
•  Appearance: Black body with gold markings
......
Is high ripple current a good thing in cap? Is this mean the Panasonic FM cap is better than FC?

TIA,
Sam


If we are talking about filtering a 100kz switching power supply, the answer would be yes..... but we're not. And while impedance, which is inversely related to ripple current (at relevant frequencies) is certainly important for PS filtering and decoupling, unfortuneately, there is more to it. I've not a clue as to why. I'll simply state that I've found some higher impedace caps to be prefferable in various roles, to better specified ones.

Ultimately, the only way to tell is to build 2 identical amps, with appropriate burn-in as dictated by your religion, where the only difference is the component under test., and make a reasonable subjective compapison, that is, if you believe in such things as I do. Even then, as components sometimes interact with each other in that overall 'voicing', such a methodology might not find the optimal for some given constraints, such as cost.

Also, realize that these FMs only go up to 50volts, while the slightly less well specified FCs go up to 100v. If you're going to place an order from digikey, you might want to order some Nichicon HEs,(pg 808-810) to further complicate matters.

Yes, I think the Black with Gold lettering would definitely make the amp sound better. It visually screams BESPOKE! :roll:
 
But I must confess, I visually prefer the Elna Cerafines, RED, probably based on my purrient attaction to the tawdry. 8)

SamL

Off Topic Q: High Ripple Current in cap.
« Reply #2 on: 17 Jun 2004, 02:34 am »
Hi Occam,

Thanks for your response. I am hoping to replace the caps in my new Pioneer DV667A DVD/SACD/DVD-A player - hence the off topic. I had the player for 4 days now and although it is details, it is also sharp, bright, incoherence with high listening fatigue. My favourite listening chair is now like a torture chamber. Since I can't afford high end universal player, I am looking at "improving" this player. I found an interesting post at diyaudio http://www.diyaudio.com/forums/showthread.php?s=&threadid=24449&perpage=10&pagenumber=7
which set me to the search and this is how I found Panasonic FM cap. Since I will be replacing a list of the caps in the psu, from what you saying, the Panasonic FM will be better over here? As for the analog section, is Nichicon Muse better than the Panasonic FC or Nichicon HE? Have anyone used them in a CD/DVD player?
With about 40+ caps to replace, the Elna is out of the $ range. Getting it is another problem as I need to order it from another vendor which cost extra in postage.


Have fun,
Sam

Occam

Off Topic Q: High Ripple Current in cap.
« Reply #3 on: 17 Jun 2004, 06:19 am »
Hey Sam,

When you posted your question and I responded

If we are talking about filtering a 100kz switching power supply, the answer would be yes..... but we're not.

I was, I believe, wrong. You actually are talking about a switching power supply and I simply didn't know what type of component you were planning on using those Panasonic FMs on.  I'm assuming that this DVD player, like most, uses a switching supply.

That very nice thread which you referred me to has that list that of replacements (for a different model) which seem eminently reasonable.
http://www.diyaudio.com/forums/showthread.php?postid=309286#post309286
using BG nx caps for audio coupling, low impedance FCs for switching PS filtering and digital decoupling, replacing the opamp(s), and a healthy dollop of polyprop bypasses, etc....

You'll note that poster was VinnieR, who posts to this forum. As he is far more experienced than me in modding these components (he has been very active on the AAsylum Digital board and the mod of the PS on the Toshiba 3950/60 is named after him), I'd suggest you PM him asking him to weigh in either in private or on this thread.

The comment on buying those Nichicon HEs, in addition, was based on the wrong assumtion that you were asking about replacing a couple of PS filter/decoupling caps, not the passle required for a DVD upgrade.

With regards to using Muse caps for analog ps bypassing over low impedance 'switching' caps (FC, FM, HE, etc...) its going to depend on your subjective 'voicing' preferences. One design I tremendouly admire uses those 'switching' caps for local analog ps decoupling while another uses Nichicon Muse KZs.  I realize that not an overly helpful answer, but it really depends on your subjective preferences and the other, interacting components. If I wasn't prepared for the effort of truly optimizing a design, I'd think Muse KZs would be a safer bet for that specific role.

The faceteous comment on the Elnas was not about  their audio qualities but rather a reference to the fact that I tend to be distracted by bright, shiny, colorful objects.  :D

SamL

Off Topic Q: High Ripple Current in cap.
« Reply #4 on: 22 Jun 2004, 10:07 pm »
Just to let those who interested of getting Pioneer DV667A/563A know that after another 10 days of burn in with no major improvement, I decided to sit the player on a small bicycle tube with $20 worth of spare coins (my poor man version of Shaktii stone  :lol: ) on top to add weight to help stabilise the player. I also change the silver IC to Cat5 and now the player sound much better in all area although the top end is still a bit sharp. I wonder if it got to do with the silver IC between the preamp and power amp or I should add another $10 of coins  :)
Anyway, the 667A now sound more like an award winning entry level player. Overall the bicycle tube, $20 coins and Cat5 IC are cheap and easy tweak that improve the sound without ruin the Warranty.

Have fun,
Sam

Malcolm Fear

Off Topic Q: High Ripple Current in cap.
« Reply #5 on: 23 Jun 2004, 12:48 am »
Hi
Place a shelf on top of the inner tube, then your player on top of that. You will hear differences in support shelf materials.
I have ended up with Corian shelving as the best I have found. You can get Corian from a kitchen bench manufacturer. Ask for their sink cut outs. Cheap.

SamL

Off Topic Q: High Ripple Current in cap.
« Reply #6 on: 1 Jul 2004, 10:11 am »
Can someone tell me the type of cap in this diagram? The cap I know is -||-


First time attaching image so not sure if it will work. Image from my photo gallery. http://www.audiocircle.com/index.php?action=gallery;area=browse;album=108


TIA,
Sam


AKSA

Off Topic Q: High Ripple Current in cap.
« Reply #7 on: 1 Jul 2004, 11:16 am »
Sam,

Difficult to be sure about this, but I think it is a metallized film cap, dielectric not known but possibly polystyrene (or polyester) but it is 1500pF, or 1.5nF.

Cheers,

Hugh