How to wire up "Boost" switch on Mysterioso Jr?

[bigstomper]

So I'm finally getting around to building up the Mysterioso Jr board I bought a very long time ago.  I read in the PDF that you can put the "Boost" as an external pot and wire it up to a 3DPT switch.  So with that in mind I laid out my box....etc...etc.  However as I'm putting it together I realized I don't know how to wire that up.  Any help?

I know it needs to take the pot in and out of the circuit, and activate the LED labeled "boost"

Thanks!  Below is a pic of the build thus far...

[nzCdog]

Wow!  Very impressive finish Bigstomper!

Looking at the schematic, I would say run a wire from Boost 3 pad on the pcb to the middle lug of your switch
Then run a wire from the top lug of your switch to lug 1 of your pot
And run a wire from the bottom lug of your switch to lug 3 of your pot
Lug 2 of the pot connects to the Boost 2 pad on pcb as usual

I haven't done this myself but hopefully that works 

[sprayfe]

Yeah man! That is a slick build!

[jkokura]

It looks like the wiring diagram in the build docs doesn't cover the 3PDT for the boost switch, so I'm not sure what Brian meant when he mentions it on page 3 here: http://www.madbeanpedals.com/projects/MysteriosoJR/docs/Mysterioso_JR_ver2.pdf

The 3PDT 'footswitchable boost' mod in the docs refers to switching between two different boost pots, meaning that you would likely have two different boost knobs on the enclosure. You only have one on your enclosure, leaving you with limited options on how to have a boost function. One thing you could try and mod it some more and come up with a footswitchable boost, perhaps by using a piece of perf board internally to switch between a pre selected amount of boost set by either a fixed resistor or a trim pot.

Essentially, what I would do is run a wire from pad's 2 and 3 of the 'boost' trim pot on the PCB to the Common lug of a 3PDT. The last common lug would be for ground. Then, on one side of the PCB you could use a fixed resistor between the lugs for the stock base value, sometime like 47K would be a small amount, but you could try and play with the value to find something you like. This is why a Trimpot might be more useful, something in the 100K range would give you a good amount to play with. Then, using a full 500K pot would give you a larger range of boost to switch to, and you would attach the other throw of the 3PDT to lugs 2 and 3 of the Pot. Lug 1 of the pot should connect to ground. Finally, you would connect an LED with a 4.7K resistor in series to power and to the boost pot side of the other lug, meaning that when you have gone to the 'boost' side of the two options, your LED would be lit. Connect the + of the LED to power, and the - to the switch and don't forget to connect the common of that side to ground also. Follow?

Your enclosure looks awesome by the way. I really like how well your decal came out. It's very detailed and clean looking. What did you use?

Jacob

[stecykmi]

Here's an image. One thing that you have to note is that the boost is at a "max" when the resistance is 0 between lug 3 and lug 2 of the boost pot. therefore, if you want the switch to actually feel like a boost, you should probably choose a pretty large value for the "non-boost" static resistor. I've suggested ~300k, but you may have to play around with that value, particularly if you're below unity gain compared to when the pedal is off. you could also use a trimpot like jkokura suggested, but personally I would use a static value just because I know i'd be very unlikely to play with it again.

also note the current limiting resistor for the switch LED. use the same value resistor as you used for the main switch (probably 4.7k).

[bigstomper]

Verrrrry interesting....

Thanks first to everyone who helped...much much appreciated!!!  Those wiring diagrams make sense and I see how to wire it now ( I think... )

OK, so I think I slightly misunderstood the "boost" pot and the "Midrange/Fullrange" Toggle from the reading in the documentation.

So...that 500k boost pot is actually attenuating the signal, and when there is no attentation (0k resistance, boost full up) it is a "full signal" passing through creating the percieved boost?  Is this correct?

And by looking at the schematic it looks like the "Midrange/Fullrange" toggle is effectively in the circuit at all times.  From reading the documentation I was thinking it was only effective when the boost was "engaged."  The documentation says...
"The MID switch lets you choose between full range and midrange in conjunction with the Boost control. You can use either an SPST or SPDT."

Hmmm....well, I am headed out the door to drive to a gig but will check back here after bit.  I will also respond to the question about the enclosure finish when I have a few more minutes to type.

[nzCdog]

Aha!  Now I learned something too... thanks guys