Amp capacitor questions. (2)

[Artie]

Is there some formula, or "rule-of-thumb" for determining amp cap size per watt? I see these after-market 1fd caps going for $100 or more. (With unwanted, fancy electronics attached.)

Also, I'm concerned with the inrush current of a large cap at initial turn-on. Could I just limit the initial current with a resistor, that's bypassed by a relay, after a 3 - 5 second turn-on delay? Know what I mean?

[luka]

1F will do you no good, unless you have only 100-300w amp, if you have 1000 or a lot more, get battery, and one of those good ones

But if you want capacitor, you will need to find 50F or even better 100F to make any diffrence

cap at initial turn-on?? you must charged it via resistor, you might get it with cap

Cap is then always charged, coz it is connected to battery

[Artie]

I'm "only" going to be running about 100W, but my main interest is in whether or not these add-on caps provide some real sonic impact, or are they just a "fad"?

Thats why I was hoping there might be some formula for determining capacity vs power-output.

[luka]

They don't impact sound, but they help hold vltage for amp high for longer time, but 1F is just way too small for that, 20, 50 or even better, 100F would make big diffrence, helping you to have your minimal voltage higher = amp clips later = you can push it harder...

but if you ask me, small caps, like 1F are just for show, none for audio

[Artie]

Thanks for the info Luka, but a 50F cap costs about $500. Thats almost more than I have in the whole system.

I'll have to do more homework on this.

[luka]

that is kinda my point, you will never pay so much for cap, which could really inpact your system, you will gain by far more with some good bat, like d3100, hc2400... not saying you need one as strong as those...

[Artie]

Ah . . . I have a friend who does high-performance engine tuning that recommends those bat's also. I'll look into them.

Thanks.