Inductors

[rasco22862]

Hi, im still doing the mod wah wah from ggg. I put the "resistor" inductor type, and the project didn´t work, now im trying to get the real indcutors. My question is : it is necesary that the inductor have 4 pins. i´m getting a 2 pin inductor.

PD: from 400 to 600 uH value right?

[Paul Marossy]

My question is : it is necesary that the inductor have 4 pins. i´m getting a 2 pin inductor.

No, it's not. The 4-pin inductors in the current manufacture CryBabys have two pins that go to the inductor and the other two are extras that don't serve any purpose other than for mounting to the PCB.

[zyxwyvu]

PD: from 400 to 600 uH value right?

You need an inductor with a value around 500 mH, not uH.

Here's some places you can get them:
http://www.smallbearelec.com/Categories.bok?category=Wah-Wah+and+Swell+Pedal+Parts
http://www.diystompboxes.com/cart/
http://www.arielfx.com/view_sub_cat.asp?main_id=7&sub_id=5
http://area51tubeaudiodesigns.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=001&Category_Code=cat003

Lots more places if you look around too.

[jonathan perez]

ive got around 6 crybaby inductors. pm me if youre interested.

[Mark Hammer]

It doesn't HAVE to be 500mh.  I built a perfectly acceptable wah with one that apparently measured 750-800mh or so.  It's a litle "throatier" than "quackier", and it likely won't do Theme From Shaft especially well, but it'll do White Room just fine.  So, 600mh won't be "textbook" but I suspect it will sound pretty darn fine to most ears.

Incidentally, since most of us lack an inductance meter and simply go on the basis of what is written on the inductor or advertised at the website, just what exactly IS the tolerance on those standard and deluxe wah inductors?  If it says 500, what sorts of deviations might one expect?

[jonathan perez]

i measured an inductor and found the mH to be 600. resistance was around 19 ohms. it measured NO differently than a handful of stock inductors that i had laying around, but sounded darn good to my ears. throaty as hell!

[Paul Marossy]

You know, after reading so many posts from people who had different experiences with inductors, I think that they are about as individual as guitars in terms of how they sound in a circuit...

[jonathan perez]

a fellow emailed me a month ago asking for a SRV wah...so i made it for him, no problem!

but he wasnt having it, as he wanted an EXACT replica of SRV's wah, saturation and thickness in all!

i explained to him that there was FAR more going on than JUST his wah, to get that level of saturation. sure, he had a vibrolux a tube screamer, and a good strat with 14's, but thats STILL not enough to nail his tone...

and hes still nagging me about that damn wah...

so yeah, i agree with you Paul...

its like when people buy a $500 tube screamer and expect it to sound like SRV...and when people realize that ceaser diaz only kept SRVs gear intact, they go ape shit! buy a stock tube screamer, change the chip and leave the rest alone...but NOOOOO...people NEED the blue LED, people NEED the choice between symetrical and asymentrical clipping, people NEED the choice between 45 different opamps and resistors, because thats what SRV did to get such fine tone! 

not that theres anything wrong with modding a tube screamer, but for those die hard fans who firmly believe thats what SRV had, i say "not a chance" to that. but i urge people to mod their tubescreamer if they dont like it, just dont expect it to get you closer to "heaven", unless its your OWN heaven...

rant alert...

oh, and so now the SRV wah guy is trying to find my supplier of inductors, because he doesnt believe me...

[The Tone God]

Whenever someone bugs me to make them "sound" like someone my typical response is "I doubt you play like him so maybe you should practise first. When you get as good as him then call me."

Andrew

[Paul Marossy]

its like when people buy a $500 tube screamer and expect it to sound like SRV...and when people realize that ceaser diaz only kept SRVs gear intact, they go ape shit!

Yeah, it's more than just using one pedal. He used to record thru several amps simultaneously, and you can't get a complex sound like that from just a Tube Screamer. Not to mention his technique, his guitars, etc., etc., etc. 

Whenever someone bugs me to make them "sound" like someone my typical response is "I doubt you play like him so maybe you should practise first. When you get as good as him then call me."

Yeah, but what if they bought a "Talent Boost" and used in conjunction with your hand built pedal?! 

[brett]

Hi
I'm winding a whole bunch of inductors and transformers (in one sense they are back-to-back inductors) at the moment.  It is VERY difficult to get two within about 10% of each other.  For the type of toroids in wahs, there are a few variables other than inductance that are likely to affect their performance.  But first - what is all this about saturation?

People refer to saturation as if it is a good thing.  But saturation leads to a loss of inductance and an increase in input current flow without increasing energy storage by the inductor.  People sometimes assume that it does the reverse, causing extra resistance (or limiting or compression).  The highest impedance to AC in inductors is usually at flux densities well below saturation (e.g. 10 to 60% of saturation).

An increase in saturation can be achieved in wahs by reducing the 470k resistor in series with the inductor.  That resistor keeps the DC flux in the toroid low, *preventing* saturation.  The 470k resistor keeps the DC current down to about 2V(?)/470kohms = 0.004mA.  Even a small amount of DC current can saturate toroidal inductors (because the relative permeability is high and there's no air gap).    Maybe someone would like to test this out and reduce the 470k resistor to 100k?

PS I'm no expert about wahs at all.  The ones I've built have been fairly ordinary.
cheers