Emu Amp Sim - C101 - 220u - minimum voltage?

[jcpst]

I tried to encapsulate it all in the title. All the 220uf caps I have on hand are either 10v, or these clown shoe 50v ones that I’m not sure I can fit.

Or, alternatively- does it need to be 220?

 

[phi1]

These are power supply filtering. Lots of pedals use 100u from 9v to gnd and 47u from Vref to gnd, so that would probably be fine here

 

[jcpst]

I was wondering if something like that might be the case- thanks!

 

[YourGuitarist]

More capacitance is always better. Look at the footprint size and find the largest capacitance per diameter. Then ensure voltage rating is at least ~1.5x expected DC. So 16v input cap for 9v pedal, 12v for vmid etc.

 

[YourGuitarist]

One caveat actually, larger capacitance means less impedance at inrush which leads to high inrush current. Some supplies and other pedals don't like that. Could add a small series resistor like 10r in supply but eh..... I know 470u has given me this issue. Not sure where the cutoff is

 

[owlexifry]

larger capacitance means less impedance at inrush which leads to high inrush current. Some supplies and other pedals don't like that.

in what way? does this cause noise or something?

always wondered what the point of series resistors in power supply inputs were for.
e.g. opamp muff:

 

[YourGuitarist]

The series resistor generally acts to limit current. With a big 220u there, it's more than likely just preventing the current draw upon plugging in from being so much as to turn off other pedals or the supply.

It's also useful for protecting diodes from being over-powered. Many schottkys and zeners (for over-voltage protection) are "fine" without the resistor but technically ... ... Sometimes you need it.

One reason against series resistors is that they can de-regulate a supply. The regulation prevents variations in the current demand of the pedal from modulating the supply voltage(s)/rails. Otherwise, big signal swings would draw more supply current which would induce a voltage drop in the SERIES RESISTOR that then lowers Vdd/Vcc/V+ etc... blahblahblah

but I digress