power supply caps...100uF 350v for 100w clone...

[massygt6]

Hi!
From some schematics I see that for a 100w version is necessary to replace the 2x 100uF 350v caps with 220uF caps...is it bad if I left the 100uF for a while? What can I expect?
thanks

[roberto]

Hi Massy!
A good 100u cap can work better than cheapy 220u, but with the same brand, half the capacitance means less punch and less bite. This is more evident as you raise the volume (because the amp needs more current and capacitors could not have enought to punch in the right way).

[massygt6]

considering that I'm using a 100w marshall out TX, with a primary imp of 1750ohm and continuos impedance from anode to anode of 32ohm, I think that this is going to be good, since that that kind of tranny should compensate the loss of punch...it has half the AtoA impedance of a fender tranny...
thanks roberto...

[mlp-mx6]

I doubt that a lack of current/filtering capacity can be compensated for by an output transformer.

[massygt6]

I intended that the punchier OT should compensate the EFFECT of that lack of filtering...I've ordered the 220uF caps, they're on the way, my question was only intended to know if I risk something running a 100w power section with those caps...
thanks

[Structo]

I think what everybody is saying is that with the bigger caps current storage capability, that when you hit low notes at power that they can compensate better instead of having sag from running out of juice.

That's why these guys with the powerful car stereos with the gigantic subwoofers put huge caps on their amps. To help carry the current that the subwoofers demand at low frequency.

[roberto]

Structo is right. Supply Caps (and supply structure in general) can change the way an amp sounds. In bass amps, using "switching" capacitors can change a dull amp in a war hammer.
But this concept fits also guitar amps. Guitar punch is basically in the low-mid of the spectrum, so good caps (and a inductance) can storage the right amount of power to punch notes but not to make them sound sterile.
By the way, at lower volumes, you'll notice less differencies (less current peaks needed), maybe just in pick attack.

[massygt6]

ok, it's very clear now...by the way, I've changed the caps to 2x220uF, so I should stay in the right ballpark now
thanks for the help!
Max