Opinions on Modding a Thomas Organ Wah

Started by Oatmeal, February 10, 2013, 02:46:14 PM

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Oatmeal

I have a Thomas organ wah from the 70's and a newer Jimi Hedndrix wah that was just given to me in trade for an orange squeezer clone I built(along with some cash, just so y'all don't think I'm an idiot). Neither of the wahs work. The Thomas Organ has a really scratchy pot and the Hendrix is dead and has not been diagnosed as of yet.

Here is what I want to do and I kind of want permission from the pedal community before I desecrate a vintage pedal.

I want to pull the TDK inductor out of the Thomas Organ and pair it with a Wipple inductor in the GGG schematic. I want to fully mod it with the multiple capacitor switch and the inductor switch. I'm going to house it in the Hendrix housing so I can have a power supply jack and I don't have to mod Thomas Organ housing. I figure if I do it this way I could put everything back to stock except for the switch holes I would have to put in the Hendrix housing.

So should I do this and does anyone have any advise? I don't want to offend the vintage pedal gods.
Anything worth doing is worth overdoing.

Quackzed

i have a few thomas organ wahs, and have modded them 'carefully' so i could put 'em back to stock. all i can say is that these are indeed original wahs made in usa - the vox'es were made in uk - clydes etc... so from a vintage standpoint i'd say don't mess with it. on the other hand they made em for quite a while and i cant say if yours is an early one or not. they are reasonably plentifull though...
what i can say is that if its got the square cube tdk inductor (bad rap) its probably not a very early one, thos had a 'stack of dimes' inductor. also i think the chicago ones are earlier, sepulveda cali a bit later...
if the pot is scratchy and unuseable, i'd personally replace the pot and keep the old pot in case. no sense in having it be unuseable.
also the jacks on these can be prone to intermitent contact and oxidation, posibly the problem with the hendrix wah as well, its mostly due to people stepping on the jacks due to their placement and causing the jacks to fail...
if your gonna use the hendrix case, why not leave the thomas alone and just copy the resistor values and add mods etc on the hendrix board rather than beating up the thomas board. circuits should be the same other than some resistor values. and your gonna replace the pot, the inductor and possibly the jacks, so why not just do it all on the hendrix. you could probably even score some (5117?) trannies if you look... i dont think the caps are special unless they were tropica fish caps which they arent, so i'd just mod/hack on the hendrix and leave the thomas alone other than the pot. btw the tdk's arent bad at all. they give a more traditional 'full on' wah sound as opposed to the more subtle 'mojo' inductor.
wink:
nothing says forever like a solid block of liquid nails!!!

Quackzed

#2
so ...
1. check the jacks on the hendrix wah, wiggle the plugs while on, check the battery cable/wires for breaks
2. once the hendrix is working, mod the snot out of IT!
3. try some pot cleaner on the thomas, and leave it stock...
... btw not trying to tell you what to do, just organizing my thoughts on the subject, i tend to ramble a bit...  ;D
nothing says forever like a solid block of liquid nails!!!

joegagan

the thomas wahs are fun for modding, the pads are large, the board is robust, lots of gooey lead in the solder. there are many things you can do without drilling holes in the board. not sure if they will ever be worth big$$ , there are hundreds of thousands of them made i think. but no need to carve up the board IMO>

my life is a tribute to the the great men and women who held this country together when the world was in trouble. my debt cannot be repaid, but i will do my best.

joegagan

i think that drilling holes in the thomas shell is a little less than kosher, but again they are possibly never going to be goldmines.
my life is a tribute to the the great men and women who held this country together when the world was in trouble. my debt cannot be repaid, but i will do my best.

Oatmeal

#5
I just want to take the inductor out of the Thomas Organ and put it with a Wipple on a new board in the Hendrix wah housing. The GGG board has a inductor switch for two inductors.
Anything worth doing is worth overdoing.

Quackzed

i mean, go for it. the thomas's arent 'hens teeth' rare. and its unlikely it'll ever buy you a car... though i have seen em go for 150-250...
nothing says forever like a solid block of liquid nails!!!

Oatmeal

Ok here are some gut shots and I've started to try to diagnose the Hendrix issues. It sounds fine in bypass, and the tone changes when you engage the wah but rocking the pedal does nothing. Anyone know what that is a symptom of?

Wah gut shot by Oatmeal_76, on Flickr

Thomas Organ gut shot by Oatmeal_76, on Flickr

Hendrix gut shot by Oatmeal_76, on Flickr
Anything worth doing is worth overdoing.

joegagan

First thing to check is the term clip. They can fit loose and have intermittent contacts. Yellow wire to pot making connection at lug?
my life is a tribute to the the great men and women who held this country together when the world was in trouble. my debt cannot be repaid, but i will do my best.

Quackzed

if the clip is ok and turning the pot, the pot could be shot. if its not the pot, try replacing the smaller electro cap, the blue one it could be failing...
found that here...
http://www.geofex.com/article_folders/wahpedl/wahped.htm
the bible of wah workings from resident guru R.G. Keen. definately worth a read if you wanna fix or tweak your wah!
nothing says forever like a solid block of liquid nails!!!