Low-ESR cap -vs- Normal cap with sunbberized.

[nina]

Hi,


Snuberizing caps seems to lower cap's ESR which make the caps chrage & discharge quicker. However, the low ESR cap like panasonic FC series is not available widely, I wonder if any one ever try comparing the FC cap and normal cap with Carlos's snubberized? Any theory can explain if their effects are the same?

Thanks!

[mauropenasa]

The snubber net serves to reduce the resonance in the ELcap net, caused by the parasite inductive (internal) element .
The low ESR even are optimized as parasitic inductance, but the principal characteristicis it's the Low ESR = Low " Equivalent Series Res .".
This parameter is not improved from external nets, and improve the performances even to low frequency.
The critical zone of resonance, managed by the snubber net is usually out of from the audio zone, and its effect in audio band is a lot of limited ( or void ).
The snubber net for the ELcap has been developed in the years 60-70 for the switching PS ( and variuos RF stage ), on account of the low efficiency that the ELcap (of the epoch) had on the high frequency troubles.

Ciao

Mauro

[jackinnj]

electrolytics, because of ESL and ESR become high impedance devices at high frequencies -- you can model this in LTSpice or TINA-TI -- the ESL for a ceramic cap can be a nano-henry (1x10e-9) or less, the ESL for a tantalum can be 2- 10 nH, and for larger electrolytics the ESL and ESR dominate the impedance at high frequencies! ( |Z| = SQRT [(ESR^2) + (XsubC - XsubL)^2]. The ESR can be a few tens of milliohms for an OSCON to many ohms for some of the dud caps found in old tube amplifiers.

[nina]

Thanks Jack, Mauro. But I am afraid those explanation are pretty hard for me to understand now

Let me put it another way.

A) using low-ESR cap like panasonic FC series
B) using ELNA audio with 0.1R+0.1UF snuberrized

Which one sound better?

[mauropenasa]

Only my experience:

Low ESR = best (low cost) PSU ELcap (all applications).

If they exist problems of PS modulations (high current spikes ) Low ESR is the only system to limit it.

The "ordinary" ELcap +snubber net have not this performance.

The audio result ?

The audio result depends from the quality of the circuit, of the layout PCB and only after from this components...

But I am not experienced in audio as other that frequent this forum...

Ciao

Mauro

[jackinnj]

Originally posted by nina
Thanks Jack, Mauro. But I am afraid those explanation are pretty hard for me to understand now

Let me put it another way.

A) using low-ESR cap like panasonic FC series
B) using ELNA audio with 0.1R+0.1UF snuberrized

Which one sound better?

As Mauro suggests, use an ELCAP, don't bother with the 0.1R/100n. The explanation for the snubber isn't particularly rigorous.

I would suggest 100n as close as possible to the power chip's V+ and V- pins.

Dress the power supply leads carefully, trying not to "parallel" them with either the output or input leads.

[nina]

Originally posted by jackinnj


As Mauro suggests, use an ELCAP, don't bother with the 0.1R/100n. The explanation for the snubber isn't particularly rigorous.

I would suggest 100n as close as possible to the power chip's V+ and V- pins.

Dress the power supply leads carefully, trying not to "parallel" them with either the output or input leads.

But the Power Supplu Design Tip highly recommend the RC?

Ordering only Pana FC cap from digkey cost ~ US$25. But sure if it worth doing it

[evo]

nina you in UK?

[Magura]

For the europeans, take a look here.

www.svalander.se

Look for the Rifa PEH-169

One of the best PSU caps around.

Magura

[nina]

Originally posted by evo
nina you in UK?

No, I now moved from London EC1 to Thailand.