Newbie question: what's the easiest way to tell the maximum voltage your

Started by Belanger, March 18, 2016, 02:07:26 PM

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Belanger

What's the easiest way to tell the maximum voltage your guitar pedal can use I know that you have to look at the data sheets but I was wondering if there's certain components that matter more then others? Do I have to figure out what each resistors value is on can I ignore the resistors all together.  And just focus on the data sheets for everything else and read the maximum voltage on the electrocylic capacitors and make sure the values of ALL capacitors are atleast double the input voltage?


I've confused myself on this one I'm sure, hopefully someone can make sense of what I'm missing here. I'm sure it's a very basic fundamental principal/s that I'm just not clicking into
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GibsonGM

Hi Belanger,

Decent question. The answer really is....what are the caps rated for, and the ICs' max ratings...and anything else that may be affected by increasing the voltage.

18V is a safe bet for the IC's (or + and - 9V), and you can look at the caps as you've already thought of, see if they're rated over what you want to increase to.   No need for 'double' rating....that "16V" or whatever, that is the WORKING VOLTAGE of the cap, so don't exceed that value.

Only takes a minute to make a list from the schematic or whatever, note the ICs and caps.   

1/4W resistors are good for oh, 250V ;)    1/2W for much more.  We'll never need to worry unless you go into tube work!


>>>>   Anyone else (PRR, Duck, R.G., Mark?) do you need to consider 'offset voltages' if you wanted to jump to 18V?    <<<
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PRR

> 1/4W resistors are good for oh, 250V

Put 250V across a 250 Ohm resistor and smell how long it lasts. (250 Watts makes short work of a 0.25W part.)

"Most" resistors in most pedals are working down nearer 0.01 Watts, so double voltage (FOUR times power) is probably still safe.

Why do you want to blindly tip bigger voltage at your pedals? That's a little like raising a home's water-pressure from a nice 40PSI to 100PSI. Maybe the pipes won't blow-up. But does it wash the dishes any faster?
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R.G.

Quote from: Belanger on March 18, 2016, 02:07:26 PM
What's the easiest way to tell the maximum voltage your guitar pedal can use
Why would you want to know?
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Phoenix

There's also little utility in increasing the voltage supply for many types of pedals, particularly anything that involves clipping, like distortions/overdrives/fuzzes, because if they are limited by anything other than rail clipping, the forward voltage of the clipping element will still be the same, so nothing will change other than increased current draw in most cases. The best thing to assume is that the design of the pedal has been optimized for the specified operating voltage.

GibsonGM

Quote from: PRR on March 19, 2016, 12:58:51 AM
> 1/4W resistors are good for oh, 250V

Put 250V across a 250 Ohm resistor and smell how long it lasts. (250 Watts makes short work of a 0.25W part.)

"Most" resistors in most pedals are working down nearer 0.01 Watts, so double voltage (FOUR times power) is probably still safe.

Why do you want to blindly tip bigger voltage at your pedals? That's a little like raising a home's water-pressure from a nice 40PSI to 100PSI. Maybe the pipes won't blow-up. But does it wash the dishes any faster?

Caveat...as long as you're aware of whether you're going to exceed their WATTAGE rating, 1/4W resistors are safe to use up to about 250V.  Of course one must be aware of what's happening as they 'move the slider up' and increase their voltage  :)
I say this in reference to tube amps...often you will fail due to too high of a voltage rather than the current thru a device (plate resistors etc).
So a glance at a schematic to see how the power flows would be a good thing!
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duck_arse

was there not a recent thread that dissected "the voltage across a cap versus its voltage rating", including signal and offsets? and all those small value electos that come in 100V/160V/200V, their ratings don't need to be doubled any further.

[only Mark left now.]
don't make me draw another line.

Belanger

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