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Vintage threads from the first ten years

Vintage Wah Wiring question ???

2/22/2000 12:32 PM
Deltablues	Vintage Wah Wiring question ??? I aquired a Fasel inductor Super Crybaby a while ago. It was badly miswired when I got it. So I got a DPDT switch and rewired it as per the Fulltone diagram. Now it sounds wonderful with a "battery". Questions: This pedal has what appears to be an original 1/8" jack for walwart usage. But did 70's Crybaby's come with power jacks? Also, when I wire the jack like it was when I received it, I get a big ol nasty 60 cycle hum out of it. Much more than just a noisy walwart would cause. Can anyone tell me (using the fulltone diagram as a reference http://www.fulltone.com/vox6080.html ), how the power jack "should" be wired?

2/22/2000 12:32 PM

Deltablues

Vintage Wah Wiring question ???

I aquired a Fasel inductor Super Crybaby a while ago. It was badly miswired when I got it. So I got a DPDT switch and rewired it as per the Fulltone diagram. Now it sounds wonderful with a "battery".

Questions:
This pedal has what appears to be an original 1/8" jack for walwart usage. But did 70's Crybaby's come with power jacks?

Also, when I wire the jack like it was when I received it, I get a big ol nasty 60 cycle hum out of it. Much more than just a noisy walwart would cause.

Can anyone tell me (using the fulltone diagram as a reference http://www.fulltone.com/vox6080.html ), how the power jack "should" be wired?

2/22/2000 2:47 PM
Mark Hammer	Works like this. The red wire that goes to the board? It carries +9vdc. That 9v could come from a battery, or it could come from an adapter. So, what you want is a jack in the way that provides that "either/or" function, so that the board gets 9v from somewhere. The jack is likely to be a closed-circuit type; one where the insertion of a plug into it changes what makes contact with what. Closed circuit jacks can come in several flavours. Effects pedals use closed circuit jacks, but they tend to use the pin-type jacks, where the plug consists of a hollow barrel that slides over the pin in the middle of the jack. Usually, there will be a legend on the side of the effect, indicating whether it is the outside of the plug or the inside that is positive. The other flavour of plug/jack is the mini phone jack type. These are more likely to be used on sweepable footpedals, because they are intended for chassis-mounting, whereas the other kind are more oriented towards board-mounting. For this flavour, the tip of the plug is positive, and the shaft is negative. If you purchase a closed-circuit jack for this adapter plug, as you insert the plug, you will see that the tip of the plug pushes the springy thing it touches AWAY from another contact. Pull the plug out, and the connection is "normalized". Okay, here is the crucial part, so listen up. Identify which solder lug each of those two contacts is connected to. This can vary from plug to plug, so I won't tell you that its the middle one, etc. You will have to identify them either by eye, or with a continuity testing device. Of course, since they are in contact with each other when there is no plug inserted, you will have to do the continuity testing with a bare plug inserted. The lug that connects to the contact which the plug tip touches? (the one that usually get pushed away from the other contact) You will want to run a wire (red, just for orthodoxy) from that lug to the place on the board where the existing red wire attaches (unsoldering the existing red wire first, naturally). The original red wire? You will want to solder that to the lug connected to the plug contact/leaf which gets disconnected by inserting a plug. Make sure the remaining lug is connected to your "star ground" connection (as in the illustration) and there you go. To sum up, what you will want to do is to wire up the new jack so that pulling the adapter plug out results in the connection between the battery positive and the board being resumed. When the plug is inserted, the battery is moved out of circuit and the power source going to the board becomes the adapter. WARNING!!!: One of the reasons you tend not to see this kind of thing explained more often in user manuals and such is because adapters vary with respect to the polarity of the plugs, and FX vary with respect to what plug-polarity they are expecting. You can really screw stuff up if you don't verify that your adapter and plug and effect were "made for each other". So check it, and check it again. If you want to be ultra safe, solder in a diode (1N914, 1N4148, 1N4001, etc.) between the board and where it connects to on the new adapter plug, making sure that the end with the stripe is soldered to the board. This will make sure that only positive voltage will find its way to your board. The down side is that you will lose about a half a volt of juice in the process. Finally, this works for just about every effect, not just wahs.

2/22/2000 2:47 PM

Mark Hammer

Works like this.

The red wire that goes to the board? It carries +9vdc. That 9v *could* come from a battery, or it *could* come from an adapter. So, what you want is a jack in the way that provides that "either/or" function, so that the board gets 9v from *somewhere*. The jack is likely to be a closed-circuit type; one where the insertion of a plug into it changes what makes contact with what.

Closed circuit jacks can come in several flavours. Effects pedals use closed circuit jacks, but they tend to use the pin-type jacks, where the plug consists of a hollow barrel that slides over the pin in the middle of the jack. Usually, there will be a legend on the side of the effect, indicating whether it is the outside of the plug or the inside that is positive.

The other flavour of plug/jack is the mini phone jack type. These are more likely to be used on sweepable footpedals, because they are intended for chassis-mounting, whereas the other kind are more oriented towards board-mounting. For this flavour, the tip of the plug is positive, and the shaft is negative.

If you purchase a closed-circuit jack for this adapter plug, as you insert the plug, you will see that the tip of the plug pushes the springy thing it touches AWAY from another contact. Pull the plug out, and the connection is "normalized".

Okay, here is the crucial part, so listen up.

Identify which solder lug each of those two contacts is connected to. This can vary from plug to plug, so I won't tell you that its the middle one, etc. You will have to identify them either by eye, or with a continuity testing device. Of course, since they are in contact with each other when there is no plug inserted, you will have to do the continuity testing with a bare plug inserted.

The lug that connects to the contact which the plug tip touches? (the one that usually get pushed away from the other contact) You will want to run a wire (red, just for orthodoxy) from that lug to the place on the board where the existing red wire attaches (unsoldering the existing red wire first, naturally). The original red wire? You will want to solder that to the lug connected to the plug contact/leaf which gets *disconnected* by inserting a plug. Make sure the remaining lug is connected to your "star ground" connection (as in the illustration) and there you go.

To sum up, what you will want to do is to wire up the new jack so that pulling the adapter plug *out* results in the connection between the battery positive and the board being resumed. When the plug is inserted, the battery is moved out of circuit and the power source going to the board becomes the adapter.

WARNING!!!: One of the reasons you tend not to see this kind of thing explained more often in user manuals and such is because adapters vary with respect to the polarity of the plugs, and FX vary with respect to what plug-polarity they are expecting. You can *really* screw stuff up if you don't verify that your adapter and plug and effect were "made for each other". So check it, and check it again.

If you want to be ultra safe, solder in a diode (1N914, 1N4148, 1N4001, etc.) between the board and where it connects to on the new adapter plug, making sure that the end with the stripe is soldered to the board. This will make sure that only positive voltage will find its way to your board. The down side is that you will lose about a half a volt of juice in the process.

Finally, this works for just about every effect, not just wahs.

2/22/2000 9:50 PM
Rebel420	More than likely, someoen wired in their own 1/8" jack. the TRUE crybaby upgrades included a small da8ughterboard (which I think they still ahve n the 1980s-1990s models, with a pair of dioedes, and some filtering to account for noisy walwarts.

2/24/2000 4:22 AM
John Fisher	Hi Larry, I have an old crybaby but it does not have a power jack but only uses a battery. I don't know the details of the specific pedal you are asking about but you have to watch out for different ground references. The newer pedals for example have the wiring so the positive is on the sleeve of the jack and the negative is in the center pin. The older devices could have the opposite configuration. The problem is when you by chance have 2 different pedals with different polarities sharing the same power source. What then happens is the reference to ground gets messed up and this is where you get a nasty hum. I am not saying that's what's happening in your case but it is something to look out for. Hope things work out for you. John Fisher

2/24/2000 4:22 AM

John Fisher

Hi Larry,
I have an old crybaby but it does not have a power jack but only uses a battery.
I don't know the details of the specific pedal you are asking about but you have to watch out for different ground references. The newer pedals for example have the wiring so the positive is on the sleeve of the jack and the negative is in the center pin. The older devices could have the opposite configuration. The problem is when you by chance have 2 different pedals with different polarities sharing the same power source. What then happens is the reference to ground gets messed up and this is where you get a nasty hum. I am not saying that's what's happening in your case but it is something to look out for.
Hope things work out for you.
John Fisher

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