5F6A Capacitor question

[travis-260]

Looking at the Ceriatone layout of the 5F6A and the schematic from weber don't agree, at least I think they don't. If you look at the weber schematic it calls for a 250uF cap for C1 and the ceriatone calls for 220uF(far right on the board). I will try to include the links. Any thoughts?

http://www.ceriatone.com/images/layoutP ... 100508.jpg

http://hem.bredband.net/b493830/5f6a_schem.jpg

[jaysg]

Not much to think about there. Depending on the brand and voltage rating chosen, there may not be a 250uF selection. The original schematic calls for a 250uF/6V cap. That doesn't mean that Fender used that exact part. You won't hear a difference.

[Zippy]

Look at the original schematic, if you like:

http://schematicheaven.com/fenderamps/b ... _schem.pdf

220 is about the same as 250 - the value of the cap that you use will probably be close.

[Sonny ReVerb]

250uF is a 'historic' or traditional value. The modern equivalent would be 220uF, which is a standard value. You often see values on older schematics such as 500pF, 5uF, 25uF, etc. The cap values have been standardized and the modern equivalents would be 510pF (or 470pF), 4.7uF, 22uF, etc.

[Richie]

And sometimes the USA caps were like 20 25 30 40 50 250 etc.. where overseas caps may be rathed like 22uf 220uf. Same as the 5k presence pot.. the UK has a 4.7k ..or a 22k middle pot on a marshall, where a USA pot might be 25K Or thats what seems, that some values are easier to get depending on where you live. More so, back in those early days.

[Sonny ReVerb]

Here's a good explanation on why they went to standardized values:

Real capacitor values (the E3 and E6 series)

You may have noticed that capacitors are not available with every possible value, for example 22µF and 47µF are readily available, but 25µF and 50µF are not!

Why is this? Imagine that you decided to make capacitors every 10µF giving 10, 20, 30, 40, 50 and so on. That seems fine, but what happens when you reach 1000? It would be pointless to make 1000, 1010, 1020, 1030 and so on because for these values 10 is a very small difference, too small to be noticeable in most circuits and capacitors cannot be made with that accuracy.

To produce a sensible range of capacitor values you need to increase the size of the 'step' as the value increases. The standard capacitor values are based on this idea and they form a series which follows the same pattern for every multiple of ten.

The E3 series (3 values for each multiple of ten)
10, 22, 47, ... then it continues 100, 220, 470, 1000, 2200, 4700, 10000 etc.
Notice how the step size increases as the value increases (values roughly double each time).

The E6 series (6 values for each multiple of ten)
10, 15, 22, 33, 47, 68, ... then it continues 100, 150, 220, 330, 470, 680, 1000 etc.
Notice how this is the E3 series with an extra value in the gaps.

The E3 series is the one most frequently used for capacitors because many types cannot be made with very accurate values.

[travis-260]

Thanks for the replies. I didn't figure it would make a difference but I'm new to all this and trying to learn as much as i can. Thanks again!