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Vintage Wah Question

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2/21/2000 7:47 PM

Vintage Wah Question

I have a vintage "fasel" Thomas Organ wah. When I first got it, it was horribly miswired (static popping etc...). I rewired the pedal as per the diagrams on Fulltone's web site. Now it sounds "Great" when used with a battery.

Here's are the questions... It came with a 1/8" jack that was wired presumably to provide the option of using a walwart. It looks original, but can anyone tell me if the Thomas Organ 70's Crybabies came with a ac power option?

Second, I tried wiring this the way it was when I got it, but I get this god awful 60 cycle hum. And before you say it's a bad walwart, it's one of the same one's I use with other pedals with no problems.

What would be the "correct" way to wire the 1/8" jack (Using the Fulltone diagram as a reference)?

2/22/2000 10:56 AM

As far as I know the originals didn't have an external power jack.

I have tried using an AC adapter with an italian "Mr. Cry Baby" and there it was that awful 60Hz hum. The AC adapter was quiet with other pedals, like my MXR Dynacomp clone and a Boss Super Overdriver. I gave up and decided to use a battery. I think the discrete cry baby circuit is much more sensitive to ps hum than op-amp based fx - so it may need an AC adapter that's better than usual.

Does the hum happen even if the wha is the only pedal between the guitar and amp? Even if your PS is very quiet you may still get hum if you've got a ground loop. Say the wha is connected to a distortion and both are powered by the same AC adapter. The grounds of both fx will be tied together by the signal cable and by the ps jacks making a loop. If you have a situation like this you can try unsoldering the ground on one of the plugs of the signal cable.

2/22/2000 11:55 AM

I have added DC jacks to a couple of my wah wahs and power them from a PS. A "normal" wall wart usually doesn't work very well with the simple circuits like wah wahs and fuzz faces. If you use a regulated, well filtered PS you should be alright, that works well for my wah wahs. Maybe try one of the new Fulltone regulated warts. You can add DC filter right inside the wah, to cut the hum as described in Craig Anderton's Projects for Guitarist book. He uses a 100ohm resistor, in-line, and a 1000uF cap across the wires.

For the jack wiring, EH used to use eighth inch jacks. The jacks had a third lug with a normally closed switch (when the jack plugs in, the switch opens) and is wired like this:

http://tinpan.fortunecity.com/solidgold/29/pj2.gif

Good luck,
JD

2/23/2000 6:30 PM
Rebel420	ACTUALLY, the ac adapter upgrades form dunlop for the crybaby had a 'daughterboard' with diodes for protection, and a r-c filter network to get rid of the 60hz hum

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