advice about simple fx looper (kind of)

[arch23]

Hello,
first time here and building effects...
I need a box that will help me switch quickly between connecting pedals through the amp fx loop and going with whole chain straight in. Looking
for a fast way to switch between 2 modes of work without messing around with the cables.
My electric design knowledge is pretty basic, so my naive design is comprised of:
3 inputs (mono jacks): loop pedals send, from amp return and other pedals in.
3 outputs (mono jack): to amp send, to loop pedals return and to amp.
A 3pdt toggle switch - ON: the loop is active, OFF: the loop is disabled, the pedals in the loop join the end of the regular chain.
I have a scheme I can upload later, but it's as simple as can be, just connecting the jacks in the correct combination and controlling it with the switch.
Will this work? Am I missing anything?
Thanks in advance
Ori

[blackieNYC]

Not simple, but not hard to wire. This is in need of a drawing but, here goes.
It's helpful to think of switches as choices - spots in the circuit that need to choose between two* things that can happen to that spot. Each spot needs an individual switch, and since we want them to all work together in unison, these individual switches will be "poles" of the same switch.  Switches 1,2&3 will choose 1x or 1y, 2 will choose 2x or 2y, 3 has 3x or 3y.  
"x" will be your "everything out front and nothing in the loop" condition.
"y" will be your "some pedals in front of the amp input and some in the loop" condition.
For your design I'm seeing three such spots that need to make choices.  Let's say you have pedals (in order) A and B always out front, and pedals C and D sometimes in the fx loop of the amp.
1 - the input of the amp needs to choose between the output of pedal B, or the output of pedal D.  Right?  Switch 1. Conditions x or y, in that order.
2 - the input of pedal C needs to choose between the output of the fx loop send or the output of pedal B.  Switch 2. conditions x or y, in that order.
3 -the input/return of the effects loop needs to choose between the output of pedal D and the fx send (for when no pedals are in the loop).  Switch 3. condition x or y, in that order.

You will need that last one, the y condition, even though no pedals are in the loop.  You know why.
Your conditions equate to the "throw" of a switch that has the "chooser" spot in the middle and the choices being either "up" or "down". ("chooser" is not an official term)

If you draw the above, you want condition x to be when all three switches go "up".   Condition y will be when all three switches go down.
Your three pole double throw switch will have this wiring:
The center "chooser" spots 1,2&3.  The "x"s are all on one side, the "y"s on the other.

You have three switching.  This uses up a 3p2t stompswitch.  There is nothing left over for an LED, but you can get a 4p2t stompswitch at smallbearelectronics.com
Now take a look at the "effects order switcher" at beavis.  http://www.beavisaudio.com/Projects/Looper-Switcher/index.htm  
This is a 4 pole switch you can use.  Forget the exact wiring you see there - think x side and y side and an x LED and any LED.  Connect as above.  Let me think about those jacks a bit.

*usually

[blackieNYC]

[arch23]

Thank you blackieNYC, I appreciate the detailed explanation and drawing.
I need to read this carefully and compare to my drawing. Although, from a quick look, I think I see similarity.
So buffers needed? no ground loops to solve? that's good.

[blackieNYC]

No buffers.  No ground loops of any consequence. And you mention a toggle switch, so that can be your "indicator" and you can skip the LED

[neilmcnasty]

What you are looking for is a "Dropout Looper"
It is designed for this purpose and will do the trick!
I can not find it online right now, but I'll dig trough my files and post it as soon as I find it...

[arch23]

neilmcnastry - thanks, hope you'll find it 

here is the scheme I came up with.


blackieNYC - there is one difference from your version: I'm not sure "From FX send output" should be connected though Switch 3 to "Fx return input". They close the loop through effects C and D, and "Fx return input" should stay disconnected. What do you think?

[neilmcnasty]

Found it!
The section labeled Loop "To" & "From" is the send and return of your amp's FX Loop
The effects you want to move in and out of your FX Loop are labeled "Effect (to dropout) - Send & Return"
And this looper box then goes where you would like to have your loop in the pedal-chain when not inserted in the Amp's FX Loop
(I guess you allready figured out that much, but I write it just to make shure, as I found it a bit confusing myself at first glance...)

http://imageshack.com/a/img912/7206/L0PRE5.jpg

[blackieNYC]

If you remove c and d from the fx loop and string them along before the amp's input, your switch must still have cabling connected to the send and return of the amp. If a jack is plugged into the amps fx return it interrupts the signal, so the fx send needs to be connected to the fx return even if the pedals are switched out of that loop.  To confirm, play thru your amp with no pedals, and then stick a plug in the return.  Silence probably.  The jack, internally, has a switch. When nothing is plugged in, the return jack is connected to the send jack.  Since you have a plug in the return jack, if you want nothing in the effects loop you need to connect the send to the return.  Unless your amp has a switch that says "insert fx loop" or something.  A fancy feature.  The imageshack drawing includes this as well, though there's something odd in that design to me, but I'm not awake yet.  It must work. It's drawn nice and published!  
Mine should work, try it with an ohmeter and a healthy imagination - this condition, that condition.
To be clear, you don't want anything to drop out, you just want to move a section of the chain from here to there?

[arch23]

neilmcnasty - thank you! I'll have a good look at this to see what I can learn from it. After you mentioned the name of this box, I did a search and found pedal maker offering such a pedal.

blackieNYC - OK, I understand the difference, both diagrams work I guess. Mine assume the cables to the amp send/return are not connected. The setup is done once per session and does not change during. That's why I need only a toggle switch and not a stomp switch. Your assume the cables stay connected.
I'm also still not sure what does the "drop" means. I want to move the effects into the end of the main chain, when I'm not using the amp fx loop. But don't want to mess with the cables connected to the effects, just the ones to/from the amp.

A question about the ground - Do I need it? (i'm not using any led) Where do I soldier the end of it - to the box?

Thank You.

[blackieNYC]

You won't need a ground on the switch. And yes, you won't have to touch any cables - if you connect that send and return for the condition x.  Even in the studio environment, it's highly, extremely, unlikely this will cause a ground loop noise. Unless you're ne of you effects has a three prong grounded AC plug, and it's in a different circuit than the amp.   Jacks will be grounded thru your metal enclosure.  Start off will all metal jacks, or wire their grounds.

[rumbletone]

blackieNYC - OK, I understand the difference, both diagrams work I guess. Mine assume the cables to the amp send/return are not connected. The setup is done once per session and does not change during. That's why I need only a toggle switch and not a stomp switch. Your assume the cables stay connected.
I'm also still not sure what does the "drop" means. I want to move the effects into the end of the main chain, when I'm not using the amp fx loop. But don't want to mess with the cables connected to the effects, just the ones to/from the amp.

Assuming I understand correctly what you're trying to do . . . . If you are not planning to connect the cables to the loop when the pedals are all in front, there is no need for the toggle switch at all - simply use switching jacks for the jack that sends to the amp's input (i.e., when the pedals are in the FX loop) that 'normals' to the jack that returns from the amp's FX send. When using the pedals in the loop, plug in all 3 cables. When using the pedals all in front of the amp, plug in a single cable to the amp's input from the jack that otherwise goes to the amp's FX return, and because you don't plug in the other 2 cables, the signal automatically normals from the 'to amp input' jack to the 'from amp FX send' jack and continues straight from the 'pre' pedals chain to the 'post' pedals chain, and then back to the 'to amp FX return' jack and into the front of the amp.

To think of it another way, when running the FX in the loop, the amp's preamp is just another pedal/loop that is inserted between the 'pre' FX and the 'post' FX, which is activated by plugging into the 'to amp input' jack. When you plug nothing in, the loop is bypassed and the signal goes straight from the 'pre' FX to the 'post' FX, skipping that loop. But instead of connecting the final 'to FX return' jack to the amp's FX return, you're plugging it into the front end of the amp. Let me know if this doesn't make sense.

This is the way I wired the I/O box on my big gigging board, so there is no need to have a toggle or footswitch (less things to forget to switch or to break) - I just plug in for the desired routing, and it's automatically switched accordingly.

[arch23]

rumbletone, thank you for joining in 

I understood the basis of your suggestion but not how to to do it... Can't visualize it yet and I don't think I know what is a switching jack. Is it a different type of jack? Do you have a link maybe?

[rumbletone]

rumbletone, thank you for joining in 

I understood the basis of your suggestion but not how to to do it... Can't visualize it yet and I don't think I know what is a switching jack. Is it a different type of jack? Do you have a link maybe?

Here is an example of a switching jack:

http://www.neutrik.com/en/audio/plugs-and-jacks/m-series/nmj4hc-s

When you insert a plug, the lug connects with the plug. When no plug is inserted, the metal contact connects with a second lug - which you would have connected (via a soldered wire) to the lug on the next jack in the chain - in other words, the act of plugging/unplugging the plug is the same as flipping a toggle switch.

This is same type of switching used in most serial FX loops and 'insert' send/returns on audio gear - plug a plug into the FX send jack, and the audio routes to the FX chain that is in the loop. Don't plug anything in, and the jack normals to the FX return jack - this is why you don't need to plug a patch cable from the FX send to FX return on the amp when not using the loop -You just leave it unplugged and the audio circuit completes by itself through switching jack.

The wiring is very simple - just wire all the jacks as you would for a simple pass through box, and then add an extra wire from the second (switched) lug of the 'to amp input' jack to the 'from FX send' jack. On mobile so can't send wiring diagram - should be some online if you search - can draw one later if you can't find one. The whole thing will easily fit in a 1590B enclosure.

[caspercody]

Sorry I did not read this whole tread, but I think this website will help with bypass loopers:

http://www.singlecoil.com/tb-strip/tbstrip.html

There are a lot of links to schematics, but this is the basic one on that page:

http://www.singlecoil.com/tb-strip/dia1.html

I did build one of these, and it works great.

Thanks
Rob

[arch23]

Thanks caspercody, good link with useful info. It's not exactly what I need though.