How does the transistor toggle work in the JHS Astro Mess and Bun Runner?

[ToneRangerAudio]

Hey y'all,

I'm currently building a dual clone of a modified Fulltone Fat Boost and a Devi Ever/JHS Hyperion/Astro Mess fuzz in a 1590BB on stripboard.

My question is on both the Astro Mess and Bun Runner from JHS, there's a switch that DPDT switch that toggles between two of the same transistors (2N2907A's) but different configurations. Can anyone confirm or clarify how this works, and how I would wire this? Do I tie together the base of both transistors and swap the configuration of the collector/emitter on either side of the toggle switch?

I know this is a very specific question, so thanks to anyone who might have any details.

Thanks!

[GibsonGM]

Hi, if you could post a picture that shows what you mean, that would be most helpful!   

[ToneRangerAudio]

Hi, if you could post a picture that shows what you mean, that would be most helpful!   

Boom! Notice the two silver 2N2907A's

[GibsonGM]

Sorry, by 'picture', I meant schematic!  Takes too much work to trace out a PCB - tho someone might be kind enough to do so on here!  I need new glasses.

[ToneRangerAudio]

Update,

I emailed Josh and he replied with this drawing! The configuration is so simple, but always great to double check. Hope this diagram helps others who want to do the same.

[Rob Strand]

All it is doing is selecting between the two transistors.

You can reduce the switching from 3PDT to DPDT by just leaving any one of the three pin permanently connected.  A single pin connected to a transistor will have no effect.

It looks like it is flipping C and E as well as changing the transistor.   It would be possible to just flip C and E of same transistor in which case it forces you to make the base the permanently connected pin.

[bluelagoon]

Heres a link and a pic something related

https://www.diystompboxes.com/smfforum/index.php?topic=120758.0

https://postimg.cc/18wDjGzZ

[antonis]

https://postimg.cc/18wDjGzZ

Doing exactly what..??