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Started by Valoosj, August 11, 2007, 10:20:56 AM

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Valoosj

I'm thinking of building 4 overdrives into 1 little box, but I have one problem at the moment in the thinking fase.
Can I just put the 4 outputs of the overdrives together in one place, and go to the master switch?
I'll make it a little clearer with a quick sketch



The three top switches are used to select 1 of the 4 overdrives, and a led will be lit with the selected overdrive.
the lower switch is the footswitch to use clean, or the selected overdrive. but what I am doing with the outputs, is that possible or not?
Quote from: frequencycentral
You squeezed it into a 1590A - you insane fool!  :icon_mrgreen:
Quote from: Scruffie
Well this... this is just silly... this can't fit in a 1590B... can it? And you're not even using SMD you mad man!

Alex C

It would probably function, but I think you'd run into the same "loading" and "tone-sucking" problems which inspired true bypass and other more recent (relatively) switching methods.  Lots of info here: http://www.geofex.com/Article_Folders/bypass/bypass.htm

Even when you're only using one effect, its output remains connected to the respective outputs of the others.  You will have the same problems mentioned in the above article, times 3.  Plus, whatever "ambient noise" such as hiss or hum that is produced by the other circuits with no input signal will always be present since the output of each is always connected.
This analysis is based on the assumption that I understand your drawing.

-Alex

Valoosj

Ok, that makes sence. I'll rethink this, and make sure I ground the outputs that I don't use. That would help, right?
Quote from: frequencycentral
You squeezed it into a 1590A - you insane fool!  :icon_mrgreen:
Quote from: Scruffie
Well this... this is just silly... this can't fit in a 1590B... can it? And you're not even using SMD you mad man!

Alex C

Grounding the outputs would be unnecessary if each output is disconnected when not in use (which is the case with true bypass).  It is at times a good idea to ground the unused inputs, though, especially in high-gain circuits. 
Here is a setup that will switch among four effects with one selected at a time, and that disconnects the IN and OUT of each effect not being used (it doesn't ground the inputs, though):


(click for larger image)

This setup allows you to use a 3PDT stomp and three toggles, like you had in your original design, but one would be a DPDT instead of SPST.  You didn't show indicators for each individual effect, and this is probably not necessary if you are using toggle switches- their position should show at a glance which effect is selected.

Switch1 selects whether you choose (with a different switch) between effects 1 and 2, or between effects 3 and 4. 
Switch2 selects between effect 1 and effect 2, but only when Switch1 is in the "effects 1/2" position. 
Switch3 selects between effect 3 and effect 4, but only when Switch1 is in the "effects 3/4" position.


Another option is to use 4 DPDT toggles, one for each effect.  Each would be wired like the signal portion of the 3PDT stomp, and would allow two or more effects to be run in series.  You could also set this up to ground the input of each, like you did on the stomp switch in your original drawing.  This may or may not be an issue; most of your chosen circuits do not seem to be in the "high gain" realm.

-Alex

Toney


One of these will solve your problem...with LEDs too.

http://www.smallbearelec.com/Detail.bok?no=46

Valoosj

Quote from: Alex C on August 11, 2007, 11:51:24 AM



(click for larger image)



-Alex

If I want to add 4 indicator leds for the different overdrives, I need to make the top 2 toggle switches 3PDT right?
Quote from: frequencycentral
You squeezed it into a 1590A - you insane fool!  :icon_mrgreen:
Quote from: Scruffie
Well this... this is just silly... this can't fit in a 1590B... can it? And you're not even using SMD you mad man!

Alex C

Quote from: Toney on August 11, 2007, 12:09:28 PMOne of these will solve your problem...with LEDs too.http://www.smallbearelec.com/Detail.bok?no=46

And have him miss out on the fun of wiring up the mess I posted?  :)

Quote from: Valoosj on August 11, 2007, 03:23:22 PMIf I want to add 4 indicator leds for the different overdrives, I need to make the top 2 toggle switches 3PDT right?

You would, but I think Toney's solution is much more practical.  It's less expensive than multiple switches, allows for LEDs, more efficiently wired, and takes up less space.  I was not aware that those are available for so cheap.

-Alex

Valoosj

I don't know about the turning knob , not that cool  8)
Quote from: frequencycentral
You squeezed it into a 1590A - you insane fool!  :icon_mrgreen:
Quote from: Scruffie
Well this... this is just silly... this can't fit in a 1590B... can it? And you're not even using SMD you mad man!