Parallel/cascade switch

[edo1123]

Hi guys. It may be a silly request, but I don't know if something like this is possible or not. I'm looking for a way to put two pedals in a box with a switch that allows me to choose between one pedal after the other or them both simultaneously in parallel. Obviously I'd use two separate foot switch to activate them individually. I'm out of ideas

[Pavlos]

Hi edo, I'm very new to the pedal building side of things so this may need a bit of assistance from someone with greater knowledge than myself, but approaching it from a guitar pickup switching viewpoint which I'm more familiar with......... here goes............there is no reason as far as I know that series / parallel switching would not be possible and could be done using a DPDT on/on switch, if you want LED indication you would need extra poles on the switch though. One possible problem could be that when linked in parallel (If I'm remebering this correctly?) there could be issues related to a mismatch in the loading of the inputs and outputs? so you might need a splitter /mixer or buffer just to keep things in order, otherwise it could adversely affect the sound quality and response of the pedals. Also in series, depending on the pedals and the order you want to put them in, some circuits don't always play nicely with each other (Early fuzz and wah pedals are notorious for not squabbling when used together) hopefully someone with far better knowledge than myself will be able to give you a beter and more in depth answer but at the very least just think of normal pedal connection one after the other as series, and using a mono Y lead to split/combine pedals as parallel.

If what you mean is to just save space and have two pedals mounted in the same box and be able to switch them on and off independantly then the answer is yes, just hardwire the output from 'pedal' 1 to the input of 'pedal' 2 and when each is in bypass then the signal would just pass through to the following output / pedal / amp. And if you want to be able to reverse the order of 'pedal' 1 and 2 then again the answer is yes, you just need a changeover switch (On/on) to swap which circuit sees the input jack first :o)

[edo1123]

So, the problem is the dpdt wiring. The series connection shouldn't be a problem, but the switch is driving me crazy. I was planning to do this with two delays, but I'm stuck and now that you told me about the splitter and the buffer I'm not sure it will work as I hoped. Do you think those two section (splitter and buffer) are strictly needed?

[Pavlos]

well I think two delays should play nicely together, although things might get a bit crazy depending on feedback levels........but that could be a good thing ;o)

As for it working, there is no reason why it shouldn't, just that on their own and in series the pedals would each be 'seeing' an individual input and output, but in parallel they would also be 'seeing each other which is where the the possible need for the buffers comes in (Expert help required on that one for if required and exactly what please) it's a bit like whe you try to use two amps at the same time, if you just use a Y lead to split your signal the input sections of the amps interact with each other and your tone changes, whereas if you use an active splitter box / amp selector, the amps can only see the guitar and not each other :o)

The switch is not too complicated, just google series/parallel wiring for guitar and you'll get plenty of good results, it's pretty easy to wire up a DPDT on/on toggle switch to do this and then to think about extra lugs to the side to add on LED indication if you want it, otherwise a label on the box to say which is which would do the job :o)

[edo1123]

Thanks you very much, man. Now I just have to build it

[Pavlos]

hey my pleasure, just glad to be able to contribute something, hope it does what you want, got plans myself for doubling up with A/B and master on/off foot switches, maybe with a toggle to reverse the order as well :o)

[rocket88]

Hey man. If I understand correctly you want to have a switch that will change which effect comes infront of the other. If that's the case, take a look at this thread, I show a diagram how to do it with a 4pdt switch so you can have LEDs, taken from the now gone beavis. If you don't want LEDs then just use a 3pdt switch and leave off the led row on the switch.

http://guitar-fx-layouts.42897.x6.nabble.com/808-and-zen-td18075.html#a18242

[Beaker]

The diagram Rocket has linked to works great - I have used it myself.

However, it is an order switcher (either pedal A into pedal B, or pedal B into pedal A). Therefore it is series only.

With this system the second delay will be delaying the signal from the first delay.


If you genuinely want to run the pedals in parallel, that is a different matter entirely, and it is what Pavlos was alluding to. This is more complicated, but you can get a whole different set of phased and synched delay effects, rather than just delayed-delay.

There are two outcomes of running pedals in parallel - the first is the most common reason/method for running parallel circuits.



#1. You split your signal in two before the pedals, (signal A through pedal A, signal B through pedal B) simultaneously, then run the ouput of each pedal through independant output jack sockets to two amplifiers (pedal A to amp A and pedal B to amp B).

Wired like this you can, for example, get a "ping-pong" delay between each amp if you get your delay timings just right - like "How Soon Is Now" by The Smiths. (Actually that was done with tremolo, but you get the idea.)



#2.  You split your signal in two before the pedals, (signal A through pedal A, signal B through pedal B) simultaneously, then you re-combine the signals and feed out through a single jack socket.

Like this, you could set one pedal slightly faster with the other, to get some Zappa style "slowly getting in synch, then out again" effects.



If you want option #1 you need a splitter circuit before the pedal circuits, a phase reversal switch to stop one amp sucking while the other is blowing and transformer isolation/ground-lift switch to minimise ground hum. You may also want a buffer in there too.

If you want option #2 you need a splitter circuit in front, a blend circuit after, to re-combine the signals, the phase switch as one pedal may be out of phase with the other, and possibly a buffer.


As you can see, this is a much more complicated system than series wiring and the switching, in combination with the series options, is going to be more complicated as well - you are going to need more footswitches!

[edo1123]

I was sure it wasn't so easy, but I'd never said it'd be so hard. So basically, in every case, I need a huge box to put all the circuit in. If I used two fuzzes to do the same thing would that be as complicated as for a delay? I'm facing a space problem, but I'd like to build something with this option.

[Beaker]

But which option do you want edo? So far you have not been very  clear as to exactly what  you want to achieve.

It may have confused me, as you mentioned two delays. In my opinion, two delays (or maybe two tremolos) are really the only pedals worth putting in parallel.

I can see absolutely no benefit whatsoever, of putting two fuzzes (or overdrives or distortions) in parallel.

I suspect (like Rocket), that what you actually mean by parallel, is simply "both pedals on at the same time".  Is this the case???

IF this is what you are looking for, you don't need any switches at all - just the usual footswitch for each pedal circuit.

Like this:

http://3.bp.blogspot.com/-T8OdqPmP_2Q/UG3WZyt28aI/AAAAAAAAC5U/lTz0RyZXAG8/s1600/!Offboard+wiring+-+dual.png


To be absolutely clear, this method will allow you to do the following:

Both pedal circuits off (bypassed).
Left hand circuit on, right hand circuit off.
Left hand circuit off, right hand circuit on.
Both pedal circuits on.

If this is what you want, it is dead easy, just wire them like the link above.

If you want to be able to flip the order of the circuits, then adding the switch in Rocket's link will let you do this too.

But again, to be absolutely clear, these are series options only, not parallel.

Let us know exactly what you want to achieve, and we can move forward and help you.

[edo1123]

Let me be the clearest possible. I have two delays A and B. I'm looking for a switch that allows me to chose between:
in1->A->B->out1
 or
in1->A->out1
in1->B->out1
with "1" I mean that it's the same and with parallel I mean one input that goes in two separate delays and the effected signals go in the same output.

[Beaker]

"Let me be the clearest possible. I have two delays A and B. I'm looking for a switch that allows me to chose between:
in1->A->B->out1
 or
in1->A->out1
in1->B->out1

Ok, that is perfectly clear to me - you want to use the two circuits in one box wiring that I linked to above. This is just a standard series wiring, that needs no extra switches, and is really easy to do.

It is what I described like this:

"Both pedal circuits off (bypassed).
Left hand circuit on, right hand circuit off.
Left hand circuit off, right hand circuit on.
Both pedal circuits on. "


HOWEVER


"with "1" I mean that it's the same and with parallel I mean one input that goes in two separate delays and the effected signals go in the same output."

I'm sorry, but I still don't get this statement. It's your use of the word parallel, which I believe you are using in error.

What you describe as "in1->A->B->out1" (what I describe as "Both pedal circuits on."), is series, not parallel in this case.

i.e.

Series:  IN > circuit A > circuit B > OUT


What you describe as parallel, implies the following:



                        / > circuit A >\
Parallel:  IN > /                      \  > OUT
                      \                       /
                       \ > circuit B > /


We are getting there!

[edo1123]

It's exactly what I mean. So, is it possible without splitter, buffer and blander ?

[Beaker]

What's exactly what you mean? Please copy and paste in the bit you are referring to.

[edo1123]

I'm referring to them both. I want to switch from series to parallel, but I don't know how. The graphic you made explain exactly what I mean with series and parallel.

[Beaker]

Ok, now we are cooking with gas.

As I have said, the series options are dead easy, no extra parts needed for the basic wiring, or just one extra 4PDT footswitch if you want the order switcher in there too.

The parallel option will need both the splitter and blender circuits, and possibly buffers as well, depending on whether the circuits are buffered already or not. You would also need to fit a phase reversal  circuit switch to one of the delay outputs.

You will also need an extra 4PDT footswitch to toggle between the series/parallel mode.

This would still all apply regardless of the type of circuit (delay or fuzz).

Unfortunately parallel operation is just more complicated to implement.

[edo1123]

what if I don't use any splitter, blander and buffer? Is it possible to do a "row" version of this switch?

[Beaker]

It won't work. It has to be like this:


                                /> > > > > CIRCUIT A > > >\
  IN>>SPLITTER>> /                                             \ >> BLENDER>>OUT
                              \                                              /
                                \>> CIRCUIT B >> PHASE>>/



The buffer, if needed, would go before the splitter.

I don't know what you mean by "row" version.

[edo1123]

Sorry. My bad. I meant  "raw". Okay. I almost got it. The last thing is where can I find a phase reverse vero?

[Pavlos]

wow, looks like my initial thoughts were kinda in the right direction, yay I'm not a total idiot.....well not quite anyway, must try harder lol

Seriously though......I've had a thought....possibly not a good one but am going to put it out there and see if it will fly anyway.....

Beaker, I might be barking up the wrong tree but would any of the existing loop/splitter/mixer circuits be workable for this? if I remember correctly one of them mentions using for drive/fuzz pedals with bass but retaining the clean sound to mix together. Reason it comes to mind is that it mentions balancing a dry signal and a wet signal, so would it be possible to slightly re-purpose the circuit to run for arguaments sake, delay A as the 'dry' signal and switch delay B between being the 'wet' signal (Parallel) or simpley straight into delay A?

And I read an interview with mr Marr a few years back where he said that the how soon is now sound was done with two amps and that the controls had to be tweaked while he played to keep them in sync with each other, talk about rod for your own back! sounds pretty damn good though :o)