Fasel Inductors...opinions?

[phillip]

I was just wondering what you guys who've used them think of the Dunlop reissue Fasel inductors...either the red or the yellow...both of which have different core types.  From what I understand, the yellow is the one that's supposed to give the "classic Fasel sound," while the red one is for a very clean sounding wah.

Are they worth the money and live up to the original Fasels, or are they just another "genuine vintage sound" marketing tactic?

TIA!
Phillip

[RDV]

I don't have an original to compare, but I bought the red fasel for my DIY vox circuit, and it sounds really good. A huge improvment over the black filmcan looking crybaby one I had.

HTH

RDV

[Paul Marossy]

There probably isn't anyhting that can replace a true vintage Fasel inductor, but I'm sure they are reasonably close. The vintage "stack of dimes" inductors are generally regarded as being the other lusted after inductor. Stuart Castledine makes some replicas of those that kick butt, too.

Have you ever read "The Technology of the Wah" at geofex.com? I wonder if there is a way to simulate a vintage Fasel inductor by using some kind of circuit that would create an asymmetrical wave form like the coveted Fasel? Sounds like an interesting idea. "Faselize your wah"!

[Peter Snowberg]

I've always wondered how wrapping an inductor with another coil would do. You would need a constant current source to drive it which adds some complexity, but you could easily create a bias field and pre-saturate the core to whatever level you wanted.

Take care,
-Peter

[Paul Marossy]

"I've always wondered how wrapping an inductor with another coil would do. You would need a constant current source to drive it which adds some complexity, but you could easily create a bias field and pre-saturate the core to whatever level you wanted."

Very interesting idea... ever actually try it?

[Paul Perry (Frostwave)]

For experimentally minded Australians, Altronics has a ferroxcube transforme core and bobbin, that allows you to make your own ferrite cored inductors.
http://www.altronics.com.au/cat.asp?cat=16&grp=210&sort=code
L5300 & L5305

[Peter Snowberg]

Very interesting idea... ever actually try it?

Sadly my crybaby walked off about 14 years ago and these days I have a Morley Power Fuzz Wah, which is a non-inductor unit.

I drew up an experimental schematic a while back around an LM2576 switching regulator and a TL072 to make a constant current supply. The LM2576 puts out power which then runs through a sensing resistor (0.1 to 0.2 ohms). The voltage developed across that resistor is processed and buffered by the TL072 and then becomes the feedback control for the switcher. That gives a stable drive current regardless of battery voltage. The switching frequency is 52KHz. There's also the LM2599 and the LM2676 to look at. The LM2676 has a switch frequency of 260KHz.

I'll post a schematic if you want to fool around with the design. 2 chips, 1 Schottky diode, 1 inductor (~100uH), 3 caps, and 9 resistors, one of which is a pot for setting the current.

My original idea was to use the circuit to saturate 1/2 of a 1K:8ohm output transformer as a distortion device. I think it would be the only pedal with magnetic saturation based distortion. I don't see any reason why it couldn't be used to pre-saturate another inductor. A 12V relay core would be perfect for influencing the other inductor.

Take care,
-Peter

[Paul Marossy]

Peter-

A magnetic saturation distortion circuit sounds very intriguing! Have you ever actually tried building it?

[Peter Snowberg]

Nope, I haven't built it yet. Maybe it's about time to breadboard one up.

Using an undersized output transformer is pretty common in tubeland to get magnetic saturation, but I always worry about power handling ability.

In all my messing with inductors and transformers (non-audio) the object was always to avoid any kind of saturation. :lol: I used to make light dimmers with big torroids wrapped in #12 for hash filters. To reduce saturation,  I used to use a tile cutting saw blade to make a gap in the ring. It seems odd to be going in the opposite direction.

Take care,
-Peter

[Manolo Dudes]

I've always wondered how wrapping an inductor with another coil would do.

We've tried it in www.pisotones.com:



The whole article is here.

We've also tried the "stick_a_small_magnet_atop_the_inductor" way   with very good results. Look here for more details.

P.S. Again, in spanish, sorry  :oops:

[Peter Snowberg]

Very cool Manolo!!!

Thanks for the information. The idea of using a magnet in there too is great!

English translations from Google can be found here and here. Unfortunatly Google gives up translating about 1/2 of the way down the second page. :?

Take care,
-Peter

[Mike Burgundy]

If I remember correctly, someone measured an old stack-of-dimes *very* meticulously to see what all the mojo was about (GEO comes to mind but i can't find anything). It turned out ot have a slightly magnetic core, which in itself is rather unique since core material is designed to be particularly non-retantive in the magnetic department.
This yields an offset response, even harmonics, etc.
a tiny magnet will apparently work fine - as Manolo said.
Is there a translation from spanish to english of that site? Mine's not too good ;(

[Gringo]

Last year, following the instructions from pisotones, i added small pieces of magnet to the inductor in my stock crybaby, and the results were excellent. Subtle, but very noticeable.

When i added an input buffer to mitigate tone sucking, it just got better.

Now i have a great wha, like 100% better than stock, and i haven't messed with all the other possible mods yet

[Paul Marossy]

So all I would have to do is add a magnetic with certain specifications to my inductor and presto?!

That seems too simple.  :wink:
But, it does make some sense. I guess I'm going to have to check out that page...

[Manolo Dudes]

For reasons beyond my knowledge, the "tiny magnet" trick does not work for every wah. A friend of mine got amazing good results in his already good sounding VOX wah. I've got great results with my old Thomas Organ CryBaby (this time in english!!!  :wink: ) but not comparable to my friend's VOX, perhaps because the original "Stack of Dimes" in mine is already somewhat magnetic (besides being very good sounding itself   ) and got great results with my Tri-Wah too but some people have told me that they couldn't hear any difference atall in theirs'.

It's important that you use a very weak magnet. I've found the typical foldable foil magnets like those used for stick-on-fridge-door publicity are ideal for this task. Stick it atop the inductor. If the inductor have a nut above as the typical crybaby/VOX, just do a hole with a paper punch.

What is even funnier is that the polarity *does* matter with the magnet. If you do not get any improvement, flip it upside down and try again.

If  you decide it to be a keeper, stick it with that gluebars used to stick paper... Pritt, for instance. It is completely removable and is strong enough to keep things in place.

Remember: weak magnet and watch that polarity  :wink:

[Paul Marossy]

Anyone ever try this on a TDK inductor? The wah I have has one of these in it, and it sounds pretty good, but it could be better...

BTW, that Tri-Wah thing is pretty cool.

[Manolo Dudes]

Just try it yourself. If you don't like, take it out and you've only lost ten minutes  :wink: This is a completely reversible modification.

[Paul Marossy]

Yes, I like that fact that it's easily reversible and simple. Lots of room for experimentation.

[Fret Wire]

Fridge magnets..... I'm gonna have to try that! I do like the yellow Dunlop Fasel, I haven't tried the red one yet. Antique Electronics has them and Fulltone pots  pretty cheap. Just type "wah" in the search field.

http://www.tubesandmore.com/

This started me thinking of the thread I started on capacitance meters. Circuit Specialists ($42.00) had one that also measured inductance (henries). Figured it would be nice for wah building. I'm wondering if the effect of the magnets on the inductor could  be measureable?

http://www.web-tronics.com/digcapandint.html

[Paul Marossy]

"I'm wondering if the effect of the magnets on the inductor could be measureable?"

You could probably see it on a scope, to some degree. I imagine that you probably would need a spectrum analyzer to really see what it's doing in the guitar frequency range (approx. 82Hz to 3kHz)
But, I'm thinking that you could run a sine wave from a signal generator thru the circuit and see what the waveform looks like. From what I have read thus far, you would be looking for an asymmetrical waveform, like the fabled original Fasel produces. If sticking the magnet on the inductor has an effect, you should be able to see something different than without it on there...

I think I'm going to try this on Tues. or Wed. - I'm really curious about this now.