dunlop wah circuit with 12v?

[KH602]

hi there, i am currently building a remote wah and i am wanting to know what changes i need to make

to the dunlop wah circuit to make it run off a 12V power supply? also how many mA should the power supply need to be?

i am only asking this because i am struggling to find 9V relays in the UK where as 12V relays are more common. i just dont

fancy sticking 12V through a crybaby circuit just incase anything blows, and i have been told to many amps through the fasel

inductors will cause alot of damage due to the high value of mH.

[petemoore]

hi there, i am currently building a remote wah and i am wanting to know what changes i need to make

to the dunlop wah circuit to make it run off a 12V power supply?
  How many parts are in it which are rated <16v ?
  also how many mA should the power supply need to be?
  Greater than the circuit or circuits loading it, for a Wah that's pretty much any adapter, I forget, but not much draw to run a couple wah transistors.
i am only asking this because i am struggling to find 9V relays in the UK where as 12V relays are more common. i just dont
  I'm not at all sure how forgiving these different relays are to input voltage variance.
fancy sticking 12V through a crybaby circuit just incase anything blows, and i have been told to many amps through the fasel
  Look in there, it's probably all caps rated for 16v, 25v maybe 50v, I say this because I haven't looked in every wah, really doubt there's a 10v in there...
  Mind that the 12v adapter probably puts out 16v with a light load such as a wah, measure the voltage output of the adapter unloaded, add say 10% for adapter input over-voltage, make sure the capacitors never see a potential higher than their rated voltage.
inductors will cause alot of damage due to the high value of mH.
  I'm almost sure the reason I don't understand that about "amps through fasel" referring to "damage @ high Mh" is that this reference is misnomer.
  For sure the inductor wired into a wah circuit isn't going to be damaged by a 12vdc circuit supply. 

[KH602]

cheers for the reply.

i know that standard is 9v through a wah, so i thought if i change it to 12v then it will help with the relay (coil) switching to make the wah remote.

I would use 9V relays just to make it easier but i cant find/get any in the UK. theres loads in the U.S

just looking at my offical pedal and all the electralitic caps are 16V. really not sure about the other caps though.

would the transitors blow?,9v through...one has 1k on collector other has 22k on the collector

[Paul Marossy]

The transistors should be fine, the datasheet says that they can handle up to 30V - http://www.datasheetcatalog.org/datasheet/motorola/MPSA14.pdf

You might need to tweak the collector and/or emitter resistors a little bit. I'm guessing that with the increase in operating voltage you'll have an increase in the overall noise level. Might not be too bad. Only one way to find out...

[anchovie]

Perhaps use your 12V supply with the relays directly and take another path from it through a 9v regulator to feed the wah? A 7809 needs a minimum of 11.5V in to give 9V out.