DIY A/B/C Pedal with individual attenuation...

[JACink]

I come in search of help, as usual

I am about to put together an A/B/C input pedal at the beginning of my effects chain, in order to quick switch between instruments when looping.

I would also like to include attenuation in the pedal, to allow me to balance levels easily. Although two of the instruments will be a bass and a piccolo bass (or guitar), the third input will be for some kind of line level device (such as a keyboard), therefore I need to be able to tame the keyboard also.

While researching how to run a keyboard through guitar/bass effects, I cam across a pretty decent article that showed this as the solution:

It said that this would provide a 25db attenuation, but the parallel resistor could be changed to a 1k Ohm giving 20db or to a 330 Ohm giving 30db attenuation.

I also investigated DIY attenuation pedals, finding that there were many different layouts and wiring options. Some where as simple as what I have shown below, a simple inline pot.

So, looking at the image below, the idea is to be able to select between 3 different inputs, each with their own levels preset. Would something this simple work?

Also, I have shown a 1k pot, but I would think that I would use a lower resistance (330 ohm) in order to give me 30db atten if needed. The LEDs should tell you which input is selected, I have shown them with individual resistors as I already have some pedalmount LEDs that have the resistor included.

So, will this work or do I need to make changes?

Thanks as always!

 

[Feral Feline]

BUMP!
Just stumbled onto this.
More than a year later, not a single reply...

OP, did your project work out?



Perhaps more complex and pricier than you wanted...
I'd go with a simple mixer so there's no signal degradation.

Guitar FX Layouts: 4 Channel Mixer
You can stick a stomp switch on each input to select the active channel.

Never hurts to have an extra channel if one goes down or the fiddler forgets to bring stuff.
If you prefer PCB for the 4-channel mixer, Mini Mixer | General Guitar Gadgets
Get just the PCB or full kit.

Or here's 3-for...
Link Removed

Link Removed


I'm guessing having a buffered signal would probably be a good idea with the keyboard or other line-level device.




To reiterate...


How'd you work out your signal management?

 

[JACink]

BUMP!
Just stumbled onto this.
More than a year later, not a single reply...

OP, did your project work out?



Perhaps more complex and pricier than you wanted...
I'd go with a simple mixer so there's no signal degradation.

Guitar FX Layouts: 4 Channel Mixer
You can stick a stomp switch on each input to select the active channel.

Never hurts to have an extra channel if one goes down or the fiddler forgets to bring stuff.
If you prefer PCB for the 4-channel mixer, Mini Mixer | General Guitar Gadgets
Get just the PCB or full kit.

Or here's 3-for...
Link Removed

Link Removed


I'm guessing having a buffered signal would probably be a good idea with the keyboard or other line-level device.




To reiterate...


How'd you work out your signal management?

Wow, I had forgotten totally about this thread!

I ended up building a pedal with an A/B switch and a Preamp. I then later have a buff'n'blend in the chain and also a small four channel mixer at the end which allows me to use different chains/intruments into one output.