Output filter Caps

Yes, adding more filter capacitance can greatly increase bottom end impact, lower the noise floor, provide greater dynamic range, etc...

Keep in mind that you will have a greater amount of "in-rush current" ( turn on surge ) if you increase the power supply reserve. As such, you might want to think about replacing and / or upgrading the rectifiers being used just to make sure that they will handle the increased load. Both rectifiers and capacitors typically die a slow death and then "go" all at one time. It would be better to replace the rectifiers now before they decide to let go later.

While you are at it, i am of the school that believes that bypass caps are also an improvement. I also believe that it is better to use a bank of multiple smaller value caps and stagger the values rather than to use a few giant cans. However, increased reserve ( more filter capacitance ) is better any way that you can get it. Just make sure that the caps are installed properly ( the correct polarity ) and are rated for well above the actual voltage of the circuit that they will be used in. Sean
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PS... If you've found a good source for parts like this at a reasonable price, i'm sure that others would like to know about it. I know i would : )

Sean, how would you feel about me calling you directly to ask a few questions? Email me at lincolncleppert@hotmail.com and I will explain.
Linc

Yes and no. Yes the "rewards" are a higher reserve peak current that gives better low frequency extension and control, frequency dynamic range etc as stated by Sean above. But...

By increasing the supply capacitance, you are forcing the transformer to push out more current through its secondary windings. The xfmr VA rating is determined by the DC power on the load side, temperature rise of the secondary, and the secondary voltage. By doubling the filter caps you are increasing the xfmr secondary current draw (what goes out of a cap must come in). Since the xfmr VA is fixed and the filter caps provide a pure capacitance load, the xfmr does not produce more power with the increased current flow. Instead, it is dissipated as heat. Heat which can damage the xfmr and the circuitry nearby (diodes, regulators, etc). The xfmr is now producing more reactive power and less "working" power. The xfmr is an integral part of the PS and, as far as I know, cannot remain a constant with respect to filter cap sizes.

And, for God's sake, be careful about monkeying around with filter caps. They have enough energy stored to kill you if you short them with yourselfdom - even months after the power is switched off.

Back in the mid-1980's, I had a Hafler DH-220 amp which I wanted to modify myself. I went to a local computer parts supply dealer, and got a pair of high quality computer-grade power supply capacitors that were twice the capacity of the stock filter caps in the Hafler. This mod made a really major improvement in not only the deep bass response of the amp, but also made some improvements to the mid-range and upper frequencies. I was able to get the replacement caps at wholesale price -- had these caps been part of the stock Hafler amp, it would have increased the retail price of the amp by a factor of 2.