Resistor Substitution? Frustration!!

Started by Ed B., March 22, 2008, 07:14:10 PM

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Ed B.

I just finished populating a Tonepad Heladito small clone chorus board and I can't find the 47ohm resistor that I supposedly ordered.  I really want to fire this thing up!! Can I sub a different resistor value until I get a 47 ohm?  The 47 ohm comes in right from the 9v in.  Any ideas??
Thanks
Ed

Faber

Well, the first thing I thought of was two 100 ohm resistors in parallel.  That'll give you 50 ohms...

GREEN FUZ

I would try substituting the nearest approximate value you have.

If you`re really desperate multiples in parallel or series will also work though not quite as elegantly. For example, 2 100 ohm resistors wired in parallel will result in 50 ohms ( as Faber stated). Five 10 ohm resistors in series results in 50 ohms also which is near enough to 47 to make little difference.

Or you could wait till you can purchase the exact value but you knew that already

springtank

Ed,

The 47-ohm resistor is only there to serve as a way of filtering noise if you happen to be using a noisy 9V wall adaptor.  If you power your pedal with a battery, the 47-ohm resistor is completely unnecessary.  If you are going to use a battery, then put a wire jumper in there and do some playing and testing.  You can test it with 9V adaptor with the wire jumper in place also - if the noise level is still OK, then you don't need that 47-ohm resistor ever.  If you find the noise level increases with your 9V adaptor, then either get a better regulated adaptor (best) or put the 47-ohm in place for adaptor use.

Note:  Using a wire jumper in place of the resistor is not going to damage anything.

Good Luck on your project!

Brian

the recluse

47 Ohm is a really common value.  Common enough that you should b able to pick it up at Radio Shack.  I know they carry 1/2 watt 47Ohm as stand alone items, but I think they have 47Ohm 1/4 watt in their assortment packs.  The assortments come out to around $.03 which isn't too bad considering many of them are usable values.