Low Impedance vs. Gen Purpose vs. High Temp Caps?

[oregoncruzer]

Hello all!

I am replacing some caps in my pre-amp on my Panasonic SA-6500. After going to mouser.com (thanks mark!) I have found many different capacitors that fit the 10 microfarad @ 25V rating of the ones I need to replace. My question is, for capacitors that fit the needs below, what are the best type between GP, Low Impedance or High temp? Any benefit to one vs.the other?

output coupling capacitors
power filtering


thanks!

[Nakdoc]

hi temp is for long life, so get the 105 degree types. low impedance refers to high frequency series inductance, which is a bad thing, so get those. "computer grade" is often used for the large filter caps, and this is a good thing as well. longer life and greater imunity to spikes.

[Martin.Ca]

Are these signal caps? Just curious. If so, maybe Panasonic "Muse" series would be nice?

[markthefixer]

Drat, I shoulda just said: EchoWars uses Panasonic FC or FM, and Nichicon PW or HE which is now UPW and UHE in mouser...

I just addressed something like this:
That's an almost total recap, there is a separate parts list for the tuner and AF boards, and you need to go through the list and figure out the values from the schematic and how they correspond to the parts numbers in the list, separate out the electrolytics from the indicated values and the schematic notations, then find the UPW or UHE Nichicon caps....

In other words I'm not going to search out an entire recap list of parts numbers, it would take me (an hour? hours?) and I've gotta get the soldering iron heated up and do some real WORK.....

a few hints: it looks like the CEA prefix on the caps in the list are electrolytics, and on Mouser I
1.search on a partial wildcard part number, like 647-upw* and hit search
2.set the in stock search flag, and hit search again
3. check off the capacitance and voltage I need and hit "apply filters"
4. if i see the cap I need, i hit buy, and back up to the page in step 3
5. If it doesn't have the cap, I go back to 3 and check higher voltages to find it.
I keep on checking values I need, and I will go UP in voltage to get a value I need, but NEVER DOWN.

It is also necessary to be sure the caps are radial leads, as opposed to an axial package, just in case... you have to either eyeball them or look at the pc board layout in the service manual.

as for that low impedance thing, it's mostly aimed at switching power supplies that operate at VERY high frequencies, and MUST have low impedance to reduce critical internal heating of the capacitor... IF the price differential isn't too big, go for it, but don't let that be your determining factor, as you won't hear a difference, because any theoretical changes are both small and the rest of the caps in the signal chain, and the not-so-high end stuff it is going into will swamp any measurable gains.

It could even hurt as the reduced impedance COULD affect the stability of that particular stage as designed, giving unexpected side effects....

[oregoncruzer]

Awesome, thanks! I'm looking at the UPW and UHE Nichicon caps as I type.