Series/parallel line selector

[Shlafenflärst]

Hi everyone ! New project ! (I know, I still haven't built the previous ones, but that will come)

Felt like playing the guitar this morning, with heavy distortion, and I thought to myself : what will it do if I put my Boss MT-2 and my Ibanez SH7 (yes I like things people don't like, and no, they don't deserve their reputation) in parallel ? Well, the result was amazing !

So it made me think it would be nice to have something to switch them both on and off at the same time. Something like a line selector, or loop box, don't know the generic term. Also, since I might some day want to be able to use it with effects in series, I thought about adding a series/parallel toggle switch. So here's my wiring pattern (yes, I know, on the top it should be send/return instead of out/in, but I had forgotten that before taking the picture) :

Would something that simple work ? And do you think I'd need ground lift switches somewhere ?

Thanks in advance !

[antonis]

Can't get you..

When 3DPT is ON, guitar IN fights with A OUT(and also with B OUT when 2nd switch set In Series)
(same stand for A & B IN and OUT jack)

You might have to reverse IN/OUT jacks so we can talk in a more sensible basis..

[Ben N]

Looks like it would work for a couple of Boss pedals, which are buffered in and out and should mix well passively. I assume the order switch is a toggle, and therefore doesn't need an LED. I'm also not sure you need it, but I would put a pulldown resistor (1M-2M2) on the input. But if you have the 3PDT already, why not make the bypass true, so the outputs of the Bosses are not connected at all in bypass?

[Shlafenflärst]

Thanks for your answers !

Can't get you..

When 3DPT is ON, guitar IN fights with A OUT(and also with B OUT when 2nd switch set In Series)
(same stand for A & B IN and OUT jack)

You might have to reverse IN/OUT jacks so we can talk in a more sensible basis..

Like I said, I remembered something too late : on the top, instead of A out, A in , B out and B in, it should be A send, A return, B send and B return. That makes more sense, right ?

Looks like it would work for a couple of Boss pedals, which are buffered in and out and should mix well passively. I assume the order switch is a toggle, and therefore doesn't need an LED. I'm also not sure you need it, but I would put a pulldown resistor (1M-2M2) on the input. But if you have the 3PDT already, why not make the bypass true, so the outputs of the Bosses are not connected at all in bypass?

The DPDT is not an order switch, it's a series/parallel switch. I guess this is unusual, and now that I think of it it's not really useful. If I want to have effects in series, I can just put them all in the A loop. It's not like I'm gonna use this on stage with pedals fixed on a pedalboard (plus putting the MT-2 and the SH7 in series is definitely a bad idea).

So here's a new wiring pattern that makes more sense. Except perhaps for the pulldown resistor, never heard of this before, just looked it up, did I get it right ?

Also, what about the ground lifts ?

Thanks in advance !

[Ben N]

Sorry, I misspoke before--I knew it was series/parallel, not order. Looks fine, although I would draw the pulldown differently, I don't think it makes any difference. I suppose it would make sense to have one of the pedals connect to ground at only the send or the return to avoid a ground loop. Breadboard it and see if it matters.

[Shlafenflärst]

Thanks !

What would you do with the pulldown ?

And yes, the breadboard is a good idea. I should definitely buy one to make some tests.

[Ben N]

I would just put a ground symbol under the resistor, rather than tie it to a specific point. Possibly the simplest place to put it is on the input jack, so why commit to a specific location in the schematic? But, like I said, that is about drawing, not building.

[moosapotamus]

In the last drawing, it looks to me like you have the resistor tied to V(+). If it's a pull down, it should go to Gnd(-), the other side of the power jack.

I wonder... if either of your pedals already have pull down resistors, would the pull down resistor that you are adding result in lower input impedance (multiple pull down resistors in parallel). And, if so, would it even be audible?

[Shlafenflärst]

Thanks ! I looked up pull down resistor, found exemples of pull up resistors, and didn't pay enough attention... I get it now.

I have the schematics from the MT-2 and the SH7, not sure I understand everything... but since I might want to use my loop box with other pedals, maybe a pulldown resistor with a toggle switch would be the best option, right ?