Quick Octavia Question

[erick4x4]

I am finishing an GGG Octavia, and realized I forgot to order the 2x 33uf caps.

I have 2x 47uf, or 2x 25uf caps.  Would either of these work, and could anyone explain what they are doing? I am really trying to learn anything I can in this new found hobby of mine!!  I am up 2 my 10th different pedal now!

Thanks!

[erick4x4]

Anyone?

[Mark Hammer]

C8 decouples/smooths the power.  Increasing it to 47uf shouldn't affect much and will certainly not impede functioning.

C6 simply limits low end, while blocking DC.  47uf will let more low end through than 22uf or 33uf.  Whether that additinal bass is actually noticeable is another matter.  You can feel free to use either 22uf or 47uf and it will still work. 

Keep in mind you can always parallel caps to get a value not found in your parts bin.  A 22uf in parallel with a 10uf will get you a value as close to a living breathing 33uf unit as possible.

That being said, very often the caps on power supply lines can be easily increased without problem  Indeed, the values selected are very often the minimum value that will do the job, rather than the "deluxe" value.  When it comes to bandwidth-limiting caps like C6, such values are often (though not always) selected to provide more than enough needed bandwidth in that circuit, just for insurance so that bass trimming doesn't accumulate over several pedals and yield an undesirably thin sound at the end of the signal chain. 

It's a bit like toxins.  If we knew that toxin X was the only one you would ever encounter in the environment, safety standards would probably be set at several more parts per million, but since we know you're exposed to a variety of toxins, safety standards are set conservatively so as to account for the sum total of all of them.  In similar fashion, no single bass-limiting cap normally does enough "damage" to the sound, but you add up all those bass-limiting caps here there and everywhere across all pedals, and you can lose a lot of bass in teeny-weeny increments unless you make a point (as a manufacturer) of using bigger values than is really needed just for that component alone.

[nero1985]

put sockets there and use the other values untill you get to order the 33uf