Vox Clyde McCoy Wah, build report,... Any ideas for Hendrix wah tone?

[mac]

After reading RG article, I suggested a friend to replace the 0.01uf cap from Q2's emitter to the inductor, and solder a socket to experiment with different values. Also to mod the input cap.
About the inductor, they must have a parasitic magnetic field to get that elusive sound. So what we did was to experiment with magnets until we found that those magnetic ads you stick in your refrigerator are ideal. They introduce a small B field which makes the pedal more vocal.

For those who want to build their own inductors this formula maybe useful:

toroidal inductor (a ring) & solenoid inductor (a cilinder)

L = K*uo*N*N*A/s

where L is the inductance in henrys, K the relative permeability of the toroid or solenoid (about 500 - 1000), uo=4*pi*10e-7 wb/A*m, N the number of loops, A the area of the toroid or solenoid, s the lenght of the toroid or solenoid. Units are in meters.
Use it to estimate. You'll never know what the really value is until you measure it with some oscilloscope or other device :-(

Since all the magnetic field is confined inside the toroid, bigger inductance can be achieved with the same number of loops. The solenoid "leaks' magnetic field on its edges. Nevertheless some friends told me that the solenoid sounds better...

mac

[Paul Marossy]

maybe the carbon comps are so far off their spec'd resistance that they hit a sweet spot... try measuring the the resistance of those cc's and compare that to their specs?

I did in fact measure them all a while ago, and they are all pretty close to their nominal values.

About the inductor, they must have a parasitic magnetic field to get that elusive sound. So what we did was to experiment with magnets until we found that those magnetic ads you stick in your refrigerator are ideal. They introduce a small B field which makes the pedal more vocal.

I heard about this trick before. I did this to my 80s Dunlop CryBaby - I've got a refrigerator magnet wrapped around the 5103 TDK inductor. I can't say that it changed dramatically, but I think it did a little bit. 

[formerMember1]

So what we did was to experiment with magnets until we found that those magnetic ads you stick in your refrigerator are ideal.

yeah, i read about this a while ago and completly forgot about it, i was meaning to try it,..but after so many cap swaps and research etc,..i completely forgot about it,....

So what are you saying to do again,...Put a magnet on the inductor?  I am using the arielfx,...but like i just take a magnet of roughly the same size and stick it to the halo?  I guess whatever end N or S that sticks and doesn't repel is fine,... 

[mac]

Placing a magnet near the inductor in such a way that the magnetic field B can flow into the inductor (1), will cause the inductance to vary since L = N*(Bautoind + Bmagnet)*A*cos(angle between B and A)/i where A is the area of the loops. I guess the trick is to keep the inductance near the original 500mH, so the magnet must be small.

(1) B  ---> ())))))))))  inductance  OK             B  !
                                                                         v
                                                             ()))))))))))) inductance     NO

The hole in the halo is a fine place to put magnets or pieces of different Fe alloys. Maybe filling it with some good Italian spaghetti may help...

mac

[formerMember1]

thanks, i will try putting a magnet inside the halo.

[Roland]

Been a while but here's a pic of a backplate of Jimi's wah and the innards of a fuzz face ..taken from a guitar mag poster (80's).

[formerMember1]

that is cool!!

Do you have  a pic of the inside of the wah?

that wah looks like a thomas crybaby or something,..

[Roland]

No, there is no pic of the wah innards, but I do have an short article on what Roger did to jimi's wah. He doesn't get specific but does share some valuable info.

The wah is a Thompson Organ company "made in Italy".

I'll see if I can post a pic of the article later today.

[formerMember1]

that would be fantastic man!!!!!


on another note,...

I am trying to get my digital recorder working right,..and it just doesn't work right,...

It records all raspy and stuff,..i have to get it checked out,...

if i get it fixed i will post clips,...

[Roland]

Just a blurb on wah's but it's a blurb from Roger mayer.



I think a neat experiment would be too make a pnp germanium version of a wah and see how it interacts with a fuzz face.

Neat, the same way it's necessary to tune up off the shelf fuzz faces is the same he tuned up off the shelf wah wah's.

[formerMember1]

 so i guess he sometimes used  an input buffer then,...

thanks for that!!!!

[formerMember1]

I have my layout with the main board on there,...and below the main board the fuzzcentral output buffer,..and i am gonna use a few short jumpers to "attach" the output buffer to the circuit,..so they are both on the same board, but no traces attach them together,..



Could the fuzzcentral output buffer, be wired up as an input buffe?  Or would i have to change some values on the board?

If so, to make the output buffer an input buffer i guess i would,.. not run a wire to the 3rd lug of wah pot but i would instead send that wire to the input of the switch...?
and instead of the output of the buffer going to the output of the switch, that would go to the input of the main board,...Right? 

thanks!!! 

http://fuzzcentral.tripod.com/mccoy/bufferlayout.gif

EDIT**  NEVERMIND   

[Roland]

 I would remove the output buffer and turn it into an input buffer. Yes a buffer is a buffer but remember there is a resistor that affects the impedance of the buffer,perhaps placing a high value potentiometer in parallel will give some "Z" control.

I believe the output buffer you mentioned has a level control, I would omit that function useing it as an input buffer as you will only have a gain of 1 anyways. It is also worth mentioning that the wah wah was the last effect in Jimi's live rig. The fuzz was the first and would drive the octavia or univibe . The wah was used as the final tone and feedback control.

Good luck

[formerMember1]

thanks,..

i thought the wah was jimi's first effect most of the time,..i always seen it like that,...oh well,....

[Roland]

Maybe the way to go is both input and output buffers with the ability to adgust input "Z" and output volume.

Useing the wah after the fuzz face is due to the pnp circuit and feedback. Later,  your right when npn fuzz faces came out it pretty well was exclusive to placing it before the fuzz.

With a totally buffered and switchable (buffers in/out) unit you'll have it all.

[formerMember1]

thanks Roland,..

Roland and Others who may know 

OK,  So i was wondering something,...

A wah has a high impedance and a Ge fuzzface has a low impedance.  THAt is why it won't "wah". 
Ok, you add an output buffer to lower the impedance and that makes it "wah" with a fuzzface.  BUT, it now "wahs" but it sounds Trebly/sustainy/obnoxious, as Steben has said in another thread. 

Steben also said that an input buffer isn't good in a wah becuase it overloads the wah itself, and makes a loss of highs/muddy.

Well, I was thinking how Roger Mayer says he added both an input and output buffer to Jimi's wah.  Many think it is a lie to confuse people. BUT, i was thinking something.  A gcb-95 wah has both an input and output buffer,..right?  Well, I always got great Jimi fuzzwah tones with a ge fuzzface and an gcb-95.  IT wasn't too trebly or "obnoxious" sustainy.

I was thinking that if i add an input buffer to my CLyde WAh, which already has an output buffer and truebypass, it will make the wah tone better with a fuzzface,..right?  Will it affect the tone of the wah when the wah is used by itself, or would the output buffer compensate for the input buffers "muddyness"?

Becuase my CLyde wah sounds fine,..(warm, thick etc,..) without the fuzzface, which also sounds warm/thick by itself too.  BUt when  i combine them,..it is too trebly and sustainy for good fuzzface and wah tones.

SO, if the above is correct i have a few questions,..

1. Does an input buffer that is always on, even if the wah is off, affect the tone of a fuzzface when the fuzzface is only on?  Or is that only an outputbuffer in a wah that affects the tone of a fuzzface, when the wah is off, and the output buffer is on?

2. Would i need an output buffer in the wah along with an input buffer in the wah to make the wah "wah" with a fuzzface?  Or only an INPUT buffer in wah will do the job?

hope this makes sense

[Roland]

Well this is the thing about fuzz faces...the input is very sensitive to what is connected to it. Adding a simple buffer alone to the input of a fuzz face will drastically change it's tone, much less a wah with buffer. There is actually another thread where a fellow is having no end of problems with one inside his guitar no less. Adding a simple cap or resistor to the input changes tone.

It could be having both input and output buffers finally gives the fuzz something it can look at without to much coloring of the tone. Experiment and find out whats right for you.

[formerMember1]

yeah thanks i will do that,...