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DIY Stompboxes => Building your own stompbox => Topic started by: tehfunk on April 16, 2009, 09:32:14 PM

Title: What 3pdt wiring do you use; why?
Post by: tehfunk on April 16, 2009, 09:32:14 PM
I use the one from tonepad's offboard wiring pdf which allows for an led. I don't see a lot of people using this method, so i was wondering what are the other methods and what are their advantages? Here's a pic of the method I use:
(http://i38.photobucket.com/albums/e101/putzdaddy/offboardwiringfordiy.jpg)
Thanks!
-Sam
Title: Re: What 3pdt wiring do you use; why?
Post by: Nitefly182 on April 16, 2009, 10:06:12 PM
I prefer to ground the input when the effect is in bypass which keeps the pedal from popping when I hit the switch. The only ground on the tonepad diagram is for the LED. I dont have a diagram though.
Title: Re: What 3pdt wiring do you use; why?
Post by: davent on April 16, 2009, 10:44:14 PM
Hello,
I went with this method, Figure B.  http://www.dazatronyx.com/support/true-bypass-technique.pdf

dave

Title: Re: What 3pdt wiring do you use; why?
Post by: Tantalum7 on April 16, 2009, 10:50:58 PM
If you follow the connections for the switch in both positions, the above tonepad diagram does ground the input during bypass.  This is also why it states so at the bottom of the diagram.  I use the tonepad method above--no pops yet.   
Title: Re: What 3pdt wiring do you use; why?
Post by: Sody54 on April 16, 2009, 10:54:20 PM
I use this one.  I think only because it was the first way I learned to do it and it made sense to my noob brain.  :icon_biggrin:

http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/The-Mod-Zone-_/EZ_3PDT_WIRING.gif.html (http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/The-Mod-Zone-_/EZ_3PDT_WIRING.gif.html)

Brian
Title: Re: What 3pdt wiring do you use; why?
Post by: FlyingZ on April 16, 2009, 11:09:48 PM
My Rat's LED diodes would flicker and alter tone when bypassed until I grounded the input.
Title: Re: What 3pdt wiring do you use; why?
Post by: MikeH on April 16, 2009, 11:26:37 PM
Quote from: Nitefly182 on April 16, 2009, 10:06:12 PM
I prefer to ground the input when the effect is in bypass which keeps the pedal from popping when I hit the switch. The only ground on the tonepad diagram is for the LED. I dont have a diagram though.

Hey if you take a second look at that tonepad diagram you'll notice that the effect input is grounded via that jumper whe it's in bypass.  I use this wiring all of the time; it works well.
Title: Re: What 3pdt wiring do you use; why?
Post by: FlyingZ on April 16, 2009, 11:53:40 PM
Quote from: MikeH on April 16, 2009, 11:26:37 PM
Hey if you take a second look at that tonepad diagram you'll notice that the effect input is grounded via that jumper whe it's in bypass.  I use this wiring all of the time; it works well.
I didn't even look  :icon_redface:
Title: Re: What 3pdt wiring do you use; why?
Post by: Nitefly182 on April 17, 2009, 12:21:05 AM
Quote from: Tantalum7 on April 16, 2009, 10:50:58 PM
If you follow the connections for the switch in both positions, the above tonepad diagram does ground the input during bypass.  This is also why it states so at the bottom of the diagram.  I use the tonepad method above--no pops yet.   

Wow I must be completely blind.
Title: Re: What 3pdt wiring do you use; why?
Post by: Tantalum7 on April 17, 2009, 12:53:47 AM
Quote from: Nitefly182 on April 17, 2009, 12:21:05 AM
Quote from: Tantalum7 on April 16, 2009, 10:50:58 PM
If you follow the connections for the switch in both positions, the above tonepad diagram does ground the input during bypass.  This is also why it states so at the bottom of the diagram.  I use the tonepad method above--no pops yet.   

Wow I must be completely blind.

Well, after your initial posting, I had to prove to myself that tonepad wasn't lying by actually following the wires.  I figured you had noticed something I didn't, and I'd been left with a floating input on about 5 pedals. 
Title: Re: What 3pdt wiring do you use; why?
Post by: Mugshot on April 17, 2009, 01:43:35 AM
what i understand from the above diagram is that when the circuit is bypassed, the LED connection is disconnected, the input gets grounded through the jumper and into the sleeve terminal of the jack. or i must be missing something.
Title: Re: What 3pdt wiring do you use; why?
Post by: Tantalum7 on April 17, 2009, 02:00:57 AM
Quote from: Mugshot on April 17, 2009, 01:43:35 AM
what i understand from the above diagram is that when the circuit is bypassed, the LED connection is disconnected, the input gets grounded through the jumper and into the sleeve terminal of the jack. or i must be missing something.

Yes, this is the conclusion I also came to when I followed the connections on the diagram above.  It states that it grounds the input in bypass, and it does.
Title: Re: What 3pdt wiring do you use; why?
Post by: anchovie on April 17, 2009, 05:16:52 AM
I used the grounded input method because it stops high-gainers from oscillating and the bypass wires picking it up as interference.
Title: Re: What 3pdt wiring do you use; why?
Post by: jefe on April 17, 2009, 07:17:22 AM
Quote from: tehfunk on April 16, 2009, 09:32:14 PM
I use the one from tonepad's offboard wiring pdf which allows for an led. I don't see a lot of people using this method, so i was wondering what are the other methods and what are their advantages?

Yo sam, that's the one I use. Well, slightly modified to remove the battery... changed the colors of the wires... but yeah, this wiring has been good to me.
Title: Re: What 3pdt wiring do you use; why?
Post by: SonicVI on April 17, 2009, 08:30:06 AM
Quote from: Sody54 on April 16, 2009, 10:54:20 PM
I use this one.  I think only because it was the first way I learned to do it and it made sense to my noob brain.  :icon_biggrin:

http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/The-Mod-Zone-_/EZ_3PDT_WIRING.gif.html (http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/The-Mod-Zone-_/EZ_3PDT_WIRING.gif.html)

Brian

Same here. It's just how I've done for years so I don't have to think about it like the other ways.
Title: Re: What 3pdt wiring do you use; why?
Post by: Toney on April 17, 2009, 08:43:53 AM

Compared em all...

Tonepad's is 'the one' in my opinion.  :icon_cool:
Title: Re: What 3pdt wiring do you use; why?
Post by: Ice-9 on April 17, 2009, 09:46:58 AM
Quote from: Sody54 on April 16, 2009, 10:54:20 PM
I use this one.  I think only because it was the first way I learned to do it and it made sense to my noob brain.  :icon_biggrin:

http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/The-Mod-Zone-_/EZ_3PDT_WIRING.gif.html (http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/The-Mod-Zone-_/EZ_3PDT_WIRING.gif.html)

Brian

If you add a jumper wire from the orange input connection to the unused centre connection it will add the ground for the input bypass. other than that its the same as the tonepad version. (i keep the led in the middle poles also)
Title: Re: What 3pdt wiring do you use; why?
Post by: gtudoran on April 28, 2009, 01:17:07 PM
Is there any way to ground the input when effect is bypassed and to use a led with millenium bypass (useing a DPDT sw insted of 3PDT sw.). An answer willl be gladly appreciate, as i whant to put 2 effects in the same enclosure(like a TS808 and a Dynacomp Compressor).

Best regards,
Gabriel
Title: Re: What 3pdt wiring do you use; why?
Post by: R.G. on April 28, 2009, 02:14:27 PM
Quote from: gtudoran on April 28, 2009, 01:17:07 PM
Is there any way to ground the input when effect is bypassed and to use a led with millenium bypass (useing a DPDT sw insted of 3PDT sw.). An answer willl be gladly appreciate, as i whant to put 2 effects in the same enclosure(like a TS808 and a Dynacomp Compressor).
Try ...reading... geofex.com. Specifically in this case, the Millenium C.
Title: Re: What 3pdt wiring do you use; why?
Post by: jimosity on April 28, 2009, 02:43:46 PM
I've always preferred the Beavis Audio version....

(http://www.beavisaudio.com/techpages/StompboxWiring/StompboxWiring.gif)
Title: Re: What 3pdt wiring do you use; why?
Post by: mikemaddux on April 28, 2009, 03:58:46 PM
Im sorry if im out of the loop here, but what is the tonal difference?!?!?

I use the EZ style of wiring 3pdt and never have a problem with switches popping....

What are ALL of the advantages of a "grounded input"
Ive built high gain pedals and never had oscillation....

The other version looks so much more complicated.
Title: Re: What 3pdt wiring do you use; why?
Post by: Projectile on April 28, 2009, 05:01:09 PM
Quote from: mikemaddux on April 28, 2009, 03:58:46 PM
Im sorry if im out of the loop here, but what is the tonal difference?!?!?

I use the EZ style of wiring 3pdt and never have a problem with switches popping....

What are ALL of the advantages of a "grounded input"
Ive built high gain pedals and never had oscillation....

The other version looks so much more complicated.

+1

I'd like to know as well. I've never had a problem with the EZ style 3pdt wiring. The only advantage I see is that it would allow you to get rid off the initial 1M pull down resistor in a lot of circuits. Other than that, it just seems pointlessly complicated. I would think that if your design includes the 1M pulldown resistor before the input cap, then there would be no reason to use the input grounded wiring scheme. However, I've seen builds that use both! I'm no expert though, so maybe others could chime in on this one.
Title: Re: What 3pdt wiring do you use; why?
Post by: davent on April 28, 2009, 05:49:15 PM
I believe grounding the input is done to help suppress oscillations that sometimes occur when certain high gain circuits are bypassed and then bleed into other circuits.

dave
Title: Re: What 3pdt wiring do you use; why?
Post by: Mr. G. on April 28, 2009, 09:25:02 PM
I use roughly the same wiring as the tonepad version.  I do this because when I built my first pedal (a true bypass loop pedal), the first loop was strictly for sending the signal to a tuner pedal.  It was first wired with the input ungrounded, and I got some bleedthrough.  It was only noticeable if the gain was up on my amp, or I had a distortion pedal on.  After that, I rewired the switch so that the input was grounded, and there was no more bleedthrough.  So, I've been wiring things like that ever since.
Title: Re: What 3pdt wiring do you use; why?
Post by: punkin on April 28, 2009, 09:42:33 PM
Quote from: tehfunk on April 16, 2009, 09:32:14 PM
I use the one from tonepad's offboard wiring pdf which allows for an led. I don't see a lot of people using this method, so i was wondering what are the other methods and what are their advantages? Here's a pic of the method I use:
(http://i38.photobucket.com/albums/e101/putzdaddy/offboardwiringfordiy.jpg)
Thanks!
-Sam

That's the one I use...easy and gets the job done.
Title: Re: What 3pdt wiring do you use; why?
Post by: Projectile on April 28, 2009, 10:42:38 PM
Quote from: davent on April 28, 2009, 05:49:15 PM
I believe grounding the input is done to help suppress oscillations that sometimes occur when certain high gain circuits are bypassed and then bleed into other circuits.

dave

Ahh, that makes sense. I've never had that happen, but I see now how bleed in high gain situations could cause a problem. I always thought it was just a pop prevention measure. Thanks for clearing that up guys.  All my distortion and OD pedals will get this wiring scheme from now on.  :icon_cool:
Title: Re: What 3pdt wiring do you use; why?
Post by: danielzink on April 28, 2009, 11:35:18 PM
I've used this for all but 1 or 2 pedals - not too different from the tonepad style.

(http://pws.cablespeed.com/danielzink/musical/3pdt-wiring.jpg)



Dan
Title: Re: What 3pdt wiring do you use; why?
Post by: Andi on April 29, 2009, 02:34:07 AM
(http://www.monkeyfx.co.uk/pictures/bypass%20strip.gif)
Title: Re: What 3pdt wiring do you use; why?
Post by: Projectile on April 29, 2009, 04:22:57 AM
Alright, so basically we still have the same 2 versions that are in the FAQ: "Standard" and "grounded input."

Everything posted here appears to be simple rearrangements of the same 2 basic wiring diagrams.
Title: Re: What 3pdt wiring do you use; why?
Post by: Paul Marossy on April 29, 2009, 10:17:48 AM
QuoteI believe grounding the input is done to help suppress oscillations that sometimes occur when certain high gain circuits are bypassed and then bleed into other circuits.

Since I starting building things towards the end of 2001, there are only two times that I have used the grounded circuit input in a guitar pedal. One of those was in my Shaka Tube build because it would oscillate in bypass mode and that somehow found its way into the signal path when in bypass mode - it was like a whining sound, IIRC. I still don't know exactly how that was happening, but the grounded circuit input method fixed it.
Title: Re: What 3pdt wiring do you use; why?
Post by: snap on April 29, 2009, 01:55:38 PM
it should be standard!
Title: Re: What 3pdt wiring do you use; why?
Post by: bumblebee on April 29, 2009, 06:42:19 PM
I use a version I came up with, i've only seen a few people use it and there's no diagram online of it. It has grounded input and regardless or not if you use a DPDT you still have grounded input.. When you use a 3PDT all grounds (LED/INPUT) are connected together.
Title: Re: What 3pdt wiring do you use; why?
Post by: Projectile on April 29, 2009, 07:10:28 PM
Quote from: bumblebee on April 29, 2009, 06:42:19 PM
I use a version I came up with, i've only seen a few people use it and there's no diagram online of it. It has grounded input and regardless or not if you use a DPDT you still have grounded input.. When you use a 3PDT all grounds (LED/INPUT) are connected together.

How can you have grounded input without a DPDT? Are you sure it's not just a reorganized version of the one that's been posted here a dozen times? In the standard input grounded wiring scheme all grounds are also connected together.
Title: Re: What 3pdt wiring do you use; why?
Post by: Mugshot on April 29, 2009, 08:54:44 PM
when you ground the input you effectively shut the circuit down, similar to turning it off. so basically the effect is off when the input is shunted to ground.


grounding the input using DPDT is possible, without an LED it is very obvious; using millenium bypass it is also the same.
Title: Re: What 3pdt wiring do you use; why?
Post by: Andi on April 30, 2009, 04:51:49 AM
Quote from: Mugshot on April 29, 2009, 08:54:44 PMwhen you ground the input you effectively shut the circuit down, similar to turning it off. so basically the effect is off when the input is shunted to ground.

The circuit is still on and still drawing current. If you grounded the circuit input but connected the output to an amp you'd still, for instance, hear any noise generated by the circuit. Grounding the input is more to prevent the circuit from squealing or oscillating as some high gain circuits can.
Title: Re: What 3pdt wiring do you use; why?
Post by: bumblebee on April 30, 2009, 05:53:14 PM
Quote from: Projectile on April 29, 2009, 07:10:28 PM
Quote from: bumblebee on April 29, 2009, 06:42:19 PM
I use a version I came up with, i've only seen a few people use it and there's no diagram online of it. It has grounded input and regardless or not if you use a DPDT you still have grounded input.. When you use a 3PDT all grounds (LED/INPUT) are connected together.

How can you have grounded input without a DPDT? Are you sure it's not just a reorganized version of the one that's been posted here a dozen times? In the standard input grounded wiring scheme all grounds are also connected together.
You cant WITHOUT a DPDT, LOL. You can have grounded input with a DPDT easily enough though.
Title: Re: What 3pdt wiring do you use; why?
Post by: Projectile on April 30, 2009, 08:02:16 PM
Quote from: bumblebee on April 30, 2009, 05:53:14 PM
Quote from: Projectile on April 29, 2009, 07:10:28 PM
Quote from: bumblebee on April 29, 2009, 06:42:19 PM
I use a version I came up with, i've only seen a few people use it and there's no diagram online of it. It has grounded input and regardless or not if you use a DPDT you still have grounded input.. When you use a 3PDT all grounds (LED/INPUT) are connected together.

How can you have grounded input without a DPDT? Are you sure it's not just a reorganized version of the one that's been posted here a dozen times? In the standard input grounded wiring scheme all grounds are also connected together.
You cant WITHOUT a DPDT, LOL. You can have grounded input with a DPDT easily enough though.

Ummm..... you said, quote: "It has grounded input and regardless or not if you use a DPDT you still have grounded input." Re-read what you typed. It doesn't make any sense. You are directly contradicting yourself.
Title: Re: What 3pdt wiring do you use; why?
Post by: Mugshot on April 30, 2009, 10:30:58 PM
Quote from: Andi on April 30, 2009, 04:51:49 AM
Quote from: Mugshot on April 29, 2009, 08:54:44 PMwhen you ground the input you effectively shut the circuit down, similar to turning it off. so basically the effect is off when the input is shunted to ground.

The circuit is still on and still drawing current. If you grounded the circuit input but connected the output to an amp you'd still, for instance, hear any noise generated by the circuit. Grounding the input is more to prevent the circuit from squealing or oscillating as some high gain circuits can.

1) andi, when the circuit is bypassed, isnt the output disconnected already from the signal line? please shed some light here :D

2) also, is it okay to add pulldown resistors to the output of the circuit when bypassed? because i do this to all my pedals that use 3pdt to help eliminate pops if possible.

3) since most circuits already have pulldown resistors for the input, what benefit can we get if we also wire the circuit to have the input shunted to ground when bypassed? from what i see there is already a ground loop in that setup.
Title: Re: What 3pdt wiring do you use; why?
Post by: Projectile on May 01, 2009, 12:56:01 AM
Quote from: Mugshot on April 30, 2009, 10:30:58 PM
1) andi, when the circuit is bypassed, isnt the output disconnected already from the signal line? please shed some light here :D

Yes, but you can still get bleedthrough if you have something very loud like an opamp oscillating in the disconnected circuit. The circuit isn't actually off until you disconnect V+ or ground from the active components. It can still amplify noise, and it can still become unstable and oscillate

Quote from: Mugshot on April 30, 2009, 10:30:58 PM
2) also, is it okay to add pulldown resistors to the output of the circuit when bypassed? because i do this to all my pedals that use 3pdt to help eliminate pops if possible.

I don't see any problem with adding a pulldown resistor to the output. As long as it is a high enough value, like 1M, it shouldn't load down the output enough to make any difference in the signal.

Quote from: Mugshot on April 30, 2009, 10:30:58 PM
3) since most circuits already have pulldown resistors for the input, what benefit can we get if we also wire the circuit to have the input shunted to ground when bypassed? from what i see there is already a ground loop in that setup.

That's exactly what we just spent the last page of this thread discussing. I asked the same question at the top of the page. No offense, but where have you been man? Sleep in class much?  :icon_lol:

from above:

Quote from: davent on April 28, 2009, 05:49:15 PM
I believe grounding the input is done to help suppress oscillations that sometimes occur when certain high gain circuits are bypassed and then bleed into other circuits.

dave


Quote from: Projectile on April 28, 2009, 10:42:38 PM
Ahh, that makes sense. I've never had that happen, but I see now how bleed in high gain situations could cause a problem. I always thought it was just a pop prevention measure. Thanks for clearing that up guys.  All my distortion and OD pedals will get this wiring scheme from now on.  :icon_cool:

Quote from: Mr. G. on April 28, 2009, 09:25:02 PM
I use roughly the same wiring as the tonepad version.  I do this because when I built my first pedal (a true bypass loop pedal), the first loop was strictly for sending the signal to a tuner pedal.  It was first wired with the input ungrounded, and I got some bleedthrough.  It was only noticeable if the gain was up on my amp, or I had a distortion pedal on.  After that, I rewired the switch so that the input was grounded, and there was no more bleedthrough.  So, I've been wiring things like that ever since.


Quote from: Paul Marossy on April 29, 2009, 10:17:48 AM
Since I starting building things towards the end of 2001, there are only two times that I have used the grounded circuit input in a guitar pedal. One of those was in my Shaka Tube build because it would oscillate in bypass mode and that somehow found its way into the signal path when in bypass mode - it was like a whining sound, IIRC. I still don't know exactly how that was happening, but the grounded circuit input method fixed it.

Quote from: Andi on April 30, 2009, 04:51:49 AM
The circuit is still on and still drawing current. If you grounded the circuit input but connected the output to an amp you'd still, for instance, hear any noise generated by the circuit. Grounding the input is more to prevent the circuit from squealing or oscillating as some high gain circuits can.
Title: Re: What 3pdt wiring do you use; why?
Post by: Mugshot on May 01, 2009, 03:06:31 AM
Quote from: Projectile on May 01, 2009, 12:56:01 AM
Quote from: Mugshot on April 30, 2009, 10:30:58 PM
3) since most circuits already have pulldown resistors for the input, what benefit can we get if we also wire the circuit to have the input shunted to ground when bypassed? from what i see there is already a ground loop in that setup.

That's exactly what we just spent the last page of this thread discussing. I asked the same question at the top of the page. No offense, but where have you been man? Sleep in class much?  :icon_lol:


hehe, probably i was reading too fast   ;D

thanks for the replies man, now i have a pretty solid idea what the application of the techniques makes to stompbox wiring  :icon_redface:
Title: Re: What 3pdt wiring do you use; why?
Post by: Mugshot on May 03, 2009, 08:47:59 PM
follow-up Q:

since the volume pot of most effects is actually a connection between output and ground, do you think it is far better to raise that pot's value to 2Meg, instead of soldering in a pull-down resistor for the output connection?
Title: Re: What 3pdt wiring do you use; why?
Post by: Projectile on May 03, 2009, 09:24:39 PM
Quote from: Mugshot on May 03, 2009, 08:47:59 PM
follow-up Q:

since the volume pot of most effects is actually a connection between output and ground, do you think it is far better to raise that pot's value to 2Meg, instead of soldering in a pull-down resistor for the output connection?

Why would you need to raise the pot's value to 2M??? A pulldown resistor is a pulldown resistor. It doesn't have to be 2M. The only reason why we use such large values is so they bleed off less of the audio signal. A 100K pot to ground is an even more effective pop prevention resistor than 2M. To also use a 2M resistor would just be redundant, and replacing the 100K volume pot with a 2M pot would just significantly increase the output impedance of the pedal when not at full volume. Not good for tube amps. Bad idea. If you already have a 100K pot to ground at the output, you already have all of the pop protection you need.
Title: Re: What 3pdt wiring do you use; why?
Post by: Mugshot on May 04, 2009, 01:56:54 AM
Quote from: Projectile on May 03, 2009, 09:24:39 PM
Quote from: Mugshot on May 03, 2009, 08:47:59 PM
follow-up Q:

since the volume pot of most effects is actually a connection between output and ground, do you think it is far better to raise that pot's value to 2Meg, instead of soldering in a pull-down resistor for the output connection?

Why would you need to raise the pot's value to 2M??? A pulldown resistor is a pulldown resistor. It doesn't have to be 2M. The only reason why we use such large values is so they bleed off less of the audio signal. A 100K pot to ground is an even more effective pop prevention resistor than 2M. To also use a 2M resistor would just be redundant, and replacing the 100K volume pot with a 2M pot would just significantly increase the output impedance of the pedal when not at full volume. Not good for tube amps. Bad idea. If you already have a 100K pot to ground at the output, you already have all of the pop protection you need.

i dont quite get some of your earlier explanation (electronics noob = me  :icon_biggrin:) but the last one was quite simple.

i get it!