Does Capacitor size matter...for sound?

[TerryD]

I'm thinking it might.
I'm about to recap my beautiful, beautiful, beautiful 66 Vibrolux.  I thought I'd be economical/cheap/too cheap?? and got the F&T caps for the power section.  I've heard great reviews on them.  But now I see that they are much smaller than the Sprague caps.  Not so much quality wise but I'm thinking the size is going to affect the sound of the amp ...and not for the better.
This might be the beginning of world war III  "The Dawn of the  Planet of theTechnocrats."
As always guys thanks for the replies

[Ed_Chambley]

No, there should be no wars on this.  The Sprague can is actually larger than the inside material.  Sluckey will post the photo shortly.  Just wait.  The choice of F&T is a great one and they are actually a little larger than the new sprague, but you would have to cut one of each open to know.


I have.  The F&T is actually larger.

[Willabe]

Ed's right. I have cut open a couple Sprague caps. They are much smaller internally than the can it self.


                 Brad     

[TerryD]

Amazing!

[Willabe]

The manufacturing technology got better, uF's to size, which is clear to see in modern caps.

But certain company's like Sprague have kept selling the 'old' style, size wise for old amp rebuilds. They fit the old eyelet boards but it's just the can size.

And we pay more for those caps.

I use the (new) small radial caps for new builds and so far they've worked just fine. 

             
                                     Brad        

[SILVERGUN]

Here's a reposted repost of a repost of that pic....

[Ed_Chambley]

Amazing!

TerryD, keep in mind there are reasons why it is necessary to keep the size.  Brad mentioned for old equipment replacement, but also some items are purchased by specification like size, width and so fourth.  To maintain selling contracts these items cannot changes.


For instance, I have a contract with the government to produce an envelope.  Over the years the item that is inserted in the envelope is smaller, but Procurement has not gotten around to changing the specifications on the envelope for 7 years.  Government ya know.


On another note, I now put the filter along the edge of the board in fender builds, but not original.  My old fender amp doghouses, I put black foam rubber in the top held by just a couple of drops of rubber cement.  Makes it easy to replace if you dont use too much glue.

[HotBluePlates]

In caps that are a fraction of a microfarad (meaning film caps), size might matter.


Caps made of different materials will approximate an "ideal cap" to varying degrees. Unfortunately, the materials that come closest to making an ideal cap also make the largest cap for a given capacitance value.


So air-dielectric caps are bigger than teflon or polystyrene caps, which are bigger than polypropylene caps, which are bigger than polyester or polycarbonate caps, which are bigger than electrolytic caps.


The vintage amps didn't use the absolute best caps available (for economy reasons), and probably used paper or polyester dielectrics most often (with some ceramic or possibly mica caps for the smallest values). Opinions vary over whether the differences are audible, or whether using "the authentic cap" or "the best possible cap" is a better sonic choice.


To get a sense of the size comparison, a 0.1uF 630v polyester cap (similar to a Mallory M150) is about 9mm x 25.4mm. I have some teflon caps of the same specs which measure 26mm x 52mm (not counting the leads). With lab measurement, the teflon cap will be shown to work "more perfectly" (though that may not be audible in a guitar amp).