Pros and Cons of Caps in PSU

I have a skeleton of a MILA that I'm building in front of me. It calls for 2 x 22uf caps in the PSU.

I have a 2 x 32uf can cap laying around. When doing the engineering on my enclosure layout I found I could save a lot of space and some money using it over the 22uf caps.

Can I get away with it? If so what would be my losses and gains doing so?

Schematic, http://www.twin-x.com/groupdiy/albums/userpics/MILA1-Updated.pdf

[quote author="abby normal"]I have a skeleton of a MILA that I'm building in front of me. It calls for 2 x 22uf caps in the PSU.

I have a 2 x 32uf can cap laying around. When doing the engineering on my enclosure layout I found I could save a lot of space and some money using it over the 22uf caps.

Can I get away with it? If so what would be my losses and gains doing so?

Schematic, http://www.twin-x.com/groupdiy/albums/userpics/MILA1-Updated.pdf[/quote]

I am no expert... but I believe that using a higher uF cap will simply provide you with better filtering to further reduce the ripple left over from the AC to DC conversion by diodes. In guitar amplifiers, some people claim that this translates into a "tighter" bass response. I assume the effect would be similar in a mic pre, but not completely sure. Again, I am no expert so I could be way off, but I think you can get away with using the bigger caps without a problem.

Mason

BTW - I built a MILA and I think it sounds great. I'm working on getting the frontpanel done and I'm hoping to post pix and sounclips at some point.

There's really no downside here.

More capacitance will gain you better filtering of the PSU. However, I would make sure that the 2x32uf can is rated for the proper voltage. Since it is smaller, I'm slightly suspect that it may not be rated for as high a voltage.

-Matt

Thanks guys!

Not smaller, I just have the ability as a can cap to mount it outside the enclosure. Doing this would open up more room internally not to mention I could use it's terminals to point to point some of the PSU also saving space.
I have one of these laying around and thought I could make good use of it.

[quote author="Nishmaster"]There's really no downside here.

More capacitance will gain you better filtering of the PSU. However, I would make sure that the 2x32uf can is rated for the proper voltage. Since it is smaller, I'm slightly suspect that it may not be rated for as high a voltage.

-Matt[/quote]

There are always exceptions. If the capacitors follow valve rectifiers you have to be a bit careful. This is because most valve rectifiers specs include a maximum value smoothing cap that they can see directly after them. If this is exceeded then the inrush charge on switch on can damage the valve.

[quote author="Nishmaster"]There's really no downside here.

More capacitance will gain you better filtering of the PSU.[/quote]
Just one thing to realise, if you significantly pump the microFarads, the switching-on action will stress the stuff in front more (transformer). So don't overdo.

And unless you use bleeder resistors (large value R in // to the cap), the cap will longer remain 'dangerous'. I was once bitten by a high voltage cap after returning from a holiday of several weeks... so use those bleeders.

Bye,

Peter