Question for Normster...

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v00d00blues79
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Question for Normster...

Post by v00d00blues79 »

Do you have a layout for your Relay PS board handy by chance? I have the same chassis and i'm struggling to get a layout worked up that would fit on the board.

Thanks,

Andy
Normster
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Re: Question for Normster...

Post by Normster »

Here's the layout I used. Board dimensions are 1.75" x 3" so just rescale the drawing to fit. Hope this helps.
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v00d00blues79
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Re: Question for Normster...

Post by v00d00blues79 »

Not to be a pain or anything, but how are the wires hooked up to the board?

Thanks,

Andy
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Re: Question for Normster...

Post by Normster »

Here ya go...

BTW, this is a voltage doubler. If you use a radioshack transformer, do not ground the center tap. I found this out the hard way.
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Normster
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Re: Question for Normster...

Post by Normster »

I forgot to add one more comment, VERY IMPORTANT!
Do NOT use this rectifier circuit with any center-tap-to-ground power source! This includes tapping off of the heater filaments!!! It will fry your PT.


Gary at Glaswerks helped me figure out the original problem I had with overheating transformers. Apparently, this circuit sends each leg alternately to ground. It works well with a RadioShack 12V transformer using the center tap and one leg for 12V or both legs for 24V, but in either case just tape off the remaining wire.
v00d00blues79
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Re: Question for Normster...

Post by v00d00blues79 »

I have one of the RS 12.6v Transformers. Its CT'd with 6.3v going to each leg. So i would tape off one 6.3v leg? Little confused by this.

Thanks for the help,

Andy
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Re: Question for Normster...

Post by Normster »

v00d00blues79 wrote:I have one of the RS 12.6v Transformers. Its CT'd with 6.3v going to each leg. So i would tape off one 6.3v leg? Little confused by this.

Thanks for the help,

Andy
Yup, tape off one 6.3V leg and use the other plus the CT to get 12V. (Actually, it's more like 16V unloaded, but don't worry about it. It's normal.) Remember, the CT is not a ground, just a halfway point in the wiring.
v00d00blues79
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Re: Question for Normster...

Post by v00d00blues79 »

Ahhh... now i understand. I'm used to grounding the CT on power transformers... this all makes sense now. Thanks!

Andy
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Re: Question for Normster...

Post by v00d00blues79 »

Normster,

Another question for you. I noticed in your pictures that you have a three prong XLR jack on the back of your amp. Do you use that to only switch between the clean and od channels? I have the same jack in mine and was wondering if that would be enough to only do that.

Thanks,

andy
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Tdale
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Re: Question for Normster...

Post by Tdale »

Normster wrote:
v00d00blues79 wrote:I have one of the RS 12.6v Transformers. Its CT'd with 6.3v going to each leg. So i would tape off one 6.3v leg? Little confused by this.

Thanks for the help,

Andy
Yup, tape off one 6.3V leg and use the other plus the CT to get 12V. (Actually, it's more like 16V unloaded, but don't worry about it. It's normal.) Remember, the CT is not a ground, just a halfway point in the wiring.
I have some problems getting that... If you tape off one of the 6.3 and use the CT, or halfway point, how do you get 12V and not just 6,3, as you normally do when you don't tape off anything? Isn't the voltage between the CT and each lead 6.3, if you tape off one, or not?

Tommy
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Re: Question for Normster...

Post by v00d00blues79 »

Thats what the voltage doubler circuit is for. Apparently you just start with 6v and then double it to 12v to get the RS tranny to work in this application.


Thanks,
Andy
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Re: Question for Normster...

Post by Normster »

Tdale wrote:
Normster wrote:
v00d00blues79 wrote:I have one of the RS 12.6v Transformers. Its CT'd with 6.3v going to each leg. So i would tape off one 6.3v leg? Little confused by this.

Thanks for the help,

Andy
Yup, tape off one 6.3V leg and use the other plus the CT to get 12V. (Actually, it's more like 16V unloaded, but don't worry about it. It's normal.) Remember, the CT is not a ground, just a halfway point in the wiring.
I have some problems getting that... If you tape off one of the 6.3 and use the CT, or halfway point, how do you get 12V and not just 6,3, as you normally do when you don't tape off anything? Isn't the voltage between the CT and each lead 6.3, if you tape off one, or not?

Tommy
I'm not exactly sure how it works, although Gary did explain it to me. What I do know is that I get about 16V using the CT and one leg, and about 34V using both legs and no CT. And yes, it is a 12.6V CT transformer. I suspect that it's magic. ;)

Voodoo, I'm only using one relay (OD) so a 3-prong works OK. I did notice that Dumble used at least 4-prongs on all builds, even those with only one relay. I suspect he did it so no one would plug a mic in the back.
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Re: Question for Normster...

Post by jazzyjoepass »

Normster wrote:
Tdale wrote:
Normster wrote:Yup, tape off one 6.3V leg and use the other plus the CT to get 12V. (Actually, it's more like 16V unloaded, but don't worry about it. It's normal.) Remember, the CT is not a ground, just a halfway point in the wiring.
I have some problems getting that... If you tape off one of the 6.3 and use the CT, or halfway point, how do you get 12V and not just 6,3, as you normally do when you don't tape off anything? Isn't the voltage between the CT and each lead 6.3, if you tape off one, or not?

Tommy
I'm not exactly sure how it works, although Gary did explain it to me. What I do know is that I get about 16V using the CT and one leg, and about 34V using both legs and no CT. And yes, it is a 12.6V CT transformer. I suspect that it's magic. ;)

Voodoo, I'm only using one relay (OD) so a 3-prong works OK. I did notice that Dumble used at least 4-prongs on all builds, even those with only one relay. I suspect he did it so no one would plug a mic in the back.
Or he had intended to add in other footswitching?
llemtt
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Re: Question for Normster...

Post by llemtt »

Usually Dumbles use a 4 conductor connector to switch OD and PAB plus having a separate supply to the pedal's leds.
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ayan
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Re: Question for Normster...

Post by ayan »

Tdale wrote:
Normster wrote:
v00d00blues79 wrote:I have one of the RS 12.6v Transformers. Its CT'd with 6.3v going to each leg. So i would tape off one 6.3v leg? Little confused by this.

Thanks for the help,

Andy
Yup, tape off one 6.3V leg and use the other plus the CT to get 12V. (Actually, it's more like 16V unloaded, but don't worry about it. It's normal.) Remember, the CT is not a ground, just a halfway point in the wiring.
I have some problems getting that... If you tape off one of the 6.3 and use the CT, or halfway point, how do you get 12V and not just 6,3, as you normally do when you don't tape off anything? Isn't the voltage between the CT and each lead 6.3, if you tape off one, or not?

Tommy
A word of caution, If I may. While using only half of the transformer -- which is what happens if one tapes off one of the 6.3VAC leads -- and a voltage doubler will get the voltage up where it's needed, the current demands for the application will have to be met by half of the transformer's secondary windings, so watch out. One way to avoid this is to tape off the CT and use a bridge rectifier on the secondary. If you do it a la Dumble, add a 12V voltage regulator to the output of that and you're be all set.

Gil
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