Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

[yanz]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

I noticed that too!

Worse ripple after a recap that is.

Right after I had finished building my PSU load tester, I obtained 2 brand new identical Enhance 300w PSUs for about $10 each.

They tested the same, actually not bad at all.

So I recapped one and surprise! Higher ripple.
I had taken out Teapo and maybe some Ltec and put in mostly Nichicon PW, a Rubycon MBZ and a UCC KZJ. The MBZ was on 5VSB, 12, 5 and 3.3v were all PW series. I didn't have an ESR meter at the time.

Testing them against each other was a lesson in humility.

Similar results from pulling the OST out of an Antec Earthwatts. Put them back in, back to normal.

The ripple is still well within ATX spec but this unexpected outcome was puzzling.

On another note, recapping a 300w Allied PSU had no ill effects. Replacing the "YC" (or CY?) brand caps with PW series had no effect on ripple. The ESR on the YC caps was pretty close to that of the Nichicon PW ones.

Have Fun,
Keri

PS. I just started on building PSU load tester #2 with Analog panel meters instead of Digital.

Maybe the Teapo caps are lower esr than the Nichi PW caps? PW is comparable to FC, iirc (not too lower esr)..

[KeriJane]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

Hi Yanz

Could it be that the PW series isn't as low in ESR?
Maybe.

But that doesn't explain the recap of the Eathwatts which was mostly Rubycon MBZ, or Oklahoma Wolf's recap with KZE, both of which are extremely low ESR.... maybe too low?

I feel that OW is probably right again (as usual) ... the design of the circuit is optimized in some way for the Teapos (or OST, etc) . My Allied recap worked out because the original YC caps were close enough to PW to have no apparent difference. Other than Nichicon's excellent reputation that is.

At least the cheapie Allied responded well to a recap. Who knows? I may have extended its lifespan somewhat.

One neat thing... the Seasonic S12--600 in my Vista Box is crammed full of KZE and KY from the factory. No worries there!

Have Fun,
Keri

[PCBONEZ]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

^^

Hes right, on jonnyguru he recapped a psu (can't remember what it was,) and it got even worse ripple than before. Teapos will be fine in a nicely designed and cooled psu like that silverstone.

They didn't pay any attention to ESR or grades when they did that swap.
Switching to Chemicon [or whatever] doesn't help when you go to a series with worse ESR that the stock crap cap.

.

[PCBONEZ]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

Stock caps in FSP Epsilon [here now] are Capxon KF and OST RLP.
FC/PW just about match on ESR but have less of a ripple rating.
If you had to use less than FC or PW that's what screwed the test.
If you did use FC/PW then it wasn't an upgrade other than brand name.
-
Would be interesting to see it done again with FM or ZL or something that actually has significantly better ESR than the stock caps.
.

[i4004]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

true....would be interesting to see ripple with both matched caps, and those with lower esr...indeed!

hm...i have some crappy psu with fan noises that could be experimented on...need to undust it first, though....oh wait, i don't have load....

kerijane should be making&selling those...

[Oklahoma Wolf]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

Stock caps in FSP Epsilon [here now] are Capxon KF and OST RLP.
FC/PW just about match on ESR but have less of a ripple rating.
If you had to use less than FC or PW that's what screwed the test.
If you did use FC/PW then it wasn't an upgrade other than brand name.
-
Would be interesting to see it done again with FM or ZL or something that actually has significantly better ESR than the stock caps.
.

The only option open to me was Chemi-Con KZE. Couldn't get my hands on anything else in the right diameters.

If you guys want to do some experiments I'd love to see the results, but the way my schedule is now I probably won't be re-doing that article anytime soon.

[PCBONEZ]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

I have a NOS [new old stock] FSP 460 watt that's easy to get at the caps in set aside to do something like that with but like you I don't have enough time right now to find my round to-it.

All the filter caps in it are 12.5mm so I can swap out about any cap I want and check the affects on the ripple.


.

[PCBONEZ]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

KZE should have been an improvement if you changed the caps on -both- sides of the coils in the filters with KZE.

You have to keep the output filters balanced for ESR if you don't want to change the operating characteristics.
- The coil in the PI filter behaves somewhat like a voltage divider only with ESR and Ripple vs Resistance and Volts as in a DC circuit.

If you lower ESR on the output side of the PI filter by a large degree relative to the caps on the input side of the filter then you encourage a greater % of the ripple to pass -through- the filter coil [vs shunting to ground before the coil] and there the O'scope will 'see' the higher % of the ripple in the output.

If you change -both- input and output filters by the same degree then you don't change the % of Ripple that passes through the coil and you should see less ripple over-all in the output.

...

It's important [in some PSU's anyway] to have lower ESR on the input side of the PI filter to shunt most of the ripple to ground -before- the coil so it isn't 'felt' in the output.
-
That's why so many [better] PSU's have two caps on the input side of the PI filter and only one in the output side.
['Two caps' may be one with lower ESR than output cap.]
.

[Oklahoma Wolf]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

I did indeed change both sides of the pi filter. I remember that because the input cap had a piece of heatshrink on it. IIRC the Epsilon had one 2200 on the input and two 2200's on the output side.

[PCBONEZ]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

In the same rail that doesn't make sense.
I'll have to look at mine again and trace it out if I have time.
.

[Oklahoma Wolf]

Re: Silverstone ST56F with Teapo capacitors – Is there any need for replacement?

That's what I thought at the time. The two output ones were parallel if I remember it right. This was one of the very first Sparkle branded Epsilons to come out, and was one I bought at NCIX.com even before you could get them in the US.