Hi all,
I am purchasing a 3PDT switch that I will be using to set up my A/B switch. The place where I am purchasing from sells a PCB for the switch.
My goal is to have an A/B switch with two LED's to show which output is active. It will be powered by either a DC jack or 9V battery. If the DC jack is being used it will cutoff the 9V battery. I am also wiring a 1/4 watt 100K resistor to the tip and sleeve of each output jack to (hopefully) eliminate any popping when engaging the switch. The Input jack will be a stereo jack that will be used as an on/off switch. When a cable is plugged in to the input jack it will be on when it is removed it will turn off. Stomp box is metal.
What I am confused about is how to use the PCB for the switch with the wiring diagram I have.
The diagram I have shows the following:
The switch has 9 poles. The Tip lead from Output 1 runs to the Upper left pole. That pole is then connected (jumped?) to the lower left pole. The Tip Lead from Output 2 runs to the lower left pole and that is connected to the upper right pole on the switch. The Center Right pole on the switch is connected to the Tip of the Input jack. The Center Top pole is connected to the short side of LED 1. The Center Center pole is connected to the sleeve of the Input Jack then to Output jack 2, and it is connected to the Right Most center pole. The Center Bottom pole is connected to the short pole of LED2. The Output Jack Sleeves are also connected together and the black lead from the DC Jack (The run goes from sleeve of output one to sleeve of output two to the DC Jack. A resistor (1K) is connected to the long side of the LED's and to the DC Jack. The DC Jack cutoff lead is run to the + battery lead. The - Battery lead is run to the Ring of the stereo Input Jack.
So, questions...How do I wire the PCB board so it makes all the jumps I need? Second I was planning on using 2 LED's mounted in a bezel with a resistor and shrink wrapped wires. So a self contained unit for my LED's
Here is a link to the PCB. http://www.bitcheslovemyswitches.com/#!/3PDT-Wiring-Board/p/39208323/category=10252302
Any help you can provide would be great! I have posted this on another board but was told that this is a great friendly environment by Lawrence at BLMS.
Thanks!!!
That board won't work. It's designed for true bypass and that's all it will do.
You need to get a different board or solder directly to the lugs of the 3PDT according to your A/B switch diagram.
Also, I don't believe that diagram will work if I understand it correctly. I don't have access to my usual diagram right now but check out the beavis audio diagrams that are out there and follow that (Google "beavis audio a/b" and it should be the first one). In essence you need the following
This is your 3PDT with the lugs horizontal.
-- | -- | --
-- | -- | --
-- | -- | --
For your signal connections
Connect lug 2 (left column, middle lug) to your input jack
Connect lug 1 (left column, top lug) to your first output jack
Connect lug 3 (left column, bottom lug) to your second output jack
Connect lug 1 with lug 6 (middle column, bottom lug)
Connect lug 3 with lug 4 (middle column, top lug)
Connect lug 5 (middle column, middle lug) with ground to prevent noise
LEDs
Connect lug 8 (right column, middle lug) to ground
Connect the negative side of LED-1 to lug 7
Connect the negative side of LED-1 to lug 9
Connect the positive sides of both LEDs to a resistor (2.2k-8.2k will be fine) coming from the positive lug of the power jack
Make sure all your ground connections are tied together (either by wire or through the case) and you're good to go!
HUGE thank you!!!
It won't work...but I found it on the interwebs...LOL
I may be describing it incorrectly...I got it from what appeared to be a pretty good source so I decided to add a picture of what I have. If still no good I have your layout which is great!!!
I did see the one at beavis but it does not show the 9v connections or the wiring to use the stereo jack as an on/off switch.
yeah, the Beavis site is being redone. If you do an image search then you'll get some saved versions of his stuff.
That diagram will work. I wouldn't personally add the resistors until you've tried it without them. It changes impedances and stuff that can make pedals go weird sometimes (if I understand it correctly).
But if you follow that diagram you posted then you'll be fine. You'll just solder to the lugs like it shows.
Thanks sonny!!!
You are talking about the resistors on the jacks correct?
If so, I'll do it with out them. If necessary i'll alligator clip them on to test it. If it's better with I'll add them if not I won't.
Quote from: Shnake on December 08, 2016, 03:36:11 PM
HUGE thank you!!!
It won't work...but I found it on the interwebs...LOL
I may be describing it incorrectly...I got it from what appeared to be a pretty good source so I decided to add a picture of what I have. If still no good I have your layout which is great!!!
I did see the one at beavis but it does not show the 9v connections or the wiring to use the stereo jack as an on/off switch.
The switch scheme from GGG will work just fine. Seeing the diagram makes it easier to decipher. Let us know how it turns out!
Thanks I will,
I haven't done anything like this since high school and that was over 35 years ago. LOL If this goes well I may purchase one of the stomp box kits and put it together for my Son.
Quote from: Shnake on December 08, 2016, 03:51:26 PM
Thanks I will,
I haven't done anything like this since high school and that was over 35 years ago. LOL If this goes well I may purchase one of the stomp box kits and put it together for my Son.
My first build was the GGG tubescreamer kit. It was a great experience. A kit is a good way to get started because it can be a bit overwhelming sourcing parts. The only drawback I see is that the PCB layouts aren't always user friendly.
One of the hard parts of building pedals is managing all the wiring. You should look at the "build docs" of the circuits you're interested in building. For example, at GGG look for the "layout and wiring diagram." You will see an image of how the circuit board is laid out. Notice where the pads are for the wires. Unless GGG has updated their layouts, you will be running lots of wires because none of the pots and switches mount right to the board. Compare that to layouts you will see in Madbean build docs (as well as those by the other guys selling boards around here) and you'll notice that pots and switches tend to be mounted right to the PCB, and the pads for wires tend to be lined up nicely with the stomp switch and power jack. This makes for a WAY cleaner/easier build.
As far as sourcing parts, Smallbear and Pedal Parts Plus, and Mammoth do a lot of the work for you in that they are pretty much selling stuff that is the right size and spec for pedal building. You will still have to do some figuring out, but you can ask tons of questions here and find the help you need.
Thanks again a lot of great info. help and resources!!!
Quote from: Shnake on December 08, 2016, 03:44:21 PM
You are talking about the resistors on the jacks correct?
If so, I'll do it with out them. If necessary i'll alligator clip them on to test it. If it's better with I'll add them if not I won't.
Yes I am. Do exactly like you said and you should be good to go. Best of luck!
:o
Ok, I have hit a bit of a stumbling block. And I have a clarification question...
So first the stumbling block.
The diagram requires a 1K resistor for the LED's. The LED's I am using came with 200k resistors. I have 100k 1/4 and 1/2 watt resistors from other projects. I have no 1K resistors. So can I substitute either the 200k resistors or the 100K resistors. I'm thinking the wattage of the resistors really does not matter because the circuit is so low powered even the 1/4 watt is likely overkill.
Ok on the clarification side...
The stereo 1/4" jack has three contact points. Tip, Ring and Sleeve, In my case I am using the Ring as my switch to close the circuit. So even though it will be in contact with the same part of the 1/4" connector as the sleeve (since I will not be using a stereo jack) I am good because I'm only running it to the negative battery and 9volt power for the LED's. Is that correct?
Thanks
Again!!!
For the resistor value, R1 is a 'current limiting resistor' or 'CLR'. It's basically there to make sure the LED doesn't get too much current and burn out the LED. 1k is enough to stop the LED burning out, but still make it reasonably bright. You could probably use anything from 500 ohms to 10k, depending on the LED.
I suspect 100k or 200k would be way too much, and your LED would be very dim. But it really depends on the specs of the LED. If you've got a breadboard you could stick them in and test the LED + resistor combination before soldering...?
The wattage, as you mention, won't really matter that much in this case.
Hi,
I made an error in my last post...the resistors I have are 200Ohm. NOT 200k. The packaging says 200 and I just ran the codes on hobby-hour.com, definately 200 Ohm.
I'm going with blue and green.
The blue specs out at 465-470nm 3.0-3.4v, 3.2 Typ, 24mA, 13000 mcd
The green is 520-525nm 3.0-3.4v, 3.2v Typ, 24mA, 20000 mcd
Given that should I use two resistors, or one for both? I'm thinking just one because only one led will be lit at a time. The switch will see to that so I should only need one 200 Ohm resistor.
If two, Can I connect them together?
If so serial or parrallel (I'm thinking if two are necessary they will need to be in serial because I am essentially combining resistance values (200 Ohms + 200 Ohms = 400 Ohms of resistance to the LEDs total.)? Parallel keeps the resistance the same but changes the voltage correct?
Joe
Hi Joe,
Assuming you use 9v supply, the resistor will be taking 5.8 volts, you want 24mA max, so you'd want
5.8 / 0.024 = 241 ohms resistor.
A 200 ohm will be super bright. 400 ohms would be nicer I reckon, and yes, you put two in series to do that. I usually use higher value resistors, as the LEDs these days are super bright. Even a 1k or 4.7k would be fine I reckon.
There's heaps of tutorials on the net about how to calculate the resistor needed for an LED - here's one for example: https://www.sparkfun.com/tutorials/219 (https://www.sparkfun.com/tutorials/219)
As for parallel resistors, that's another thing you might want to read up on. Two 200 ohm resistors in parallel would be 100 ohms total resistance. More reading: https://learn.sparkfun.com/tutorials/series-and-parallel-circuits (https://learn.sparkfun.com/tutorials/series-and-parallel-circuits)
Thanks That makes sense...I'll connect them then shrink wrap them.
OK,
All wired up. I didn't shrink all the wrap down just yet.
Interesting problem...
The box works perfectly when I have a 9v battery attached. When I plug it in nothing. Nothing at the box at all. Funny think is I have a daisy chain plug from the AC converter so I can hook a bunch of pedals up to one AC converter. If I plug in the pedal and the mini amp I am using for testing all is fine until I plug the 1/4" cable from the stomp box into the amp. Then is shuts everything down. I've tried it plugged in with and with out a battery, no change.
I thought that I might have a problem with the wiring on the DC jack but I can't see where that is. I've run it against the diagram several times and all looks good. I have run my multi meter over it and and all the conections that conect to it on both the positive and Negative sides all good.
I am wondering about the amount of resistance I am running over the LED's. The LEDs I have came with 200 Ohm resistors. The design calls for a 1K resistor. I took the suggestion from "mjg" and connected two 200 Ohm resistors in serial (so 400 Ohms of resistance) to the lamps to dim them a bit. Is is possible that the extra 200 Ohms of resistance is actually causing the switch to open when connected to the 9V converter?
I ask because the resistors are connected directly to the second Positive lead of the 9V jack.
I'm also wondering if since the box is metal and I have connected all of the sleeves from the jacks together and to the 9v jack (and the battery) have I created a ground loop once I connect the jack and the 1/4" cable to the amp?
I'm also getting a "POP" when I switch between jacks so after I get this worked out I'll test it with the resistors over the jacks.
Any help would be great.
I've posted a photo. It's still messy I haven't moved the wires around.