Two circuits at the input/output jacks?

[wray]

I have connected a 1.5 tone bender and a range master together. I connected two circuits at the input output jacks.  I used batteries with both positive ground circuits.  It sounds like it is being overloaded. Can I use only one battery for both? Would a charge pump need to be employed to achieve unity of the two circuits? Is there anyone out there who has done this?

Thanks,
Wray

[GibsonGM]

Hi Wray, welcome!   Well, normally you would want to split your signal, run each 'new signal' into your desired circuits, and then blend them back together again.   

This prevents the circuits from interacting with each other, which may be what you're hearing.   They sort of "fight" if you don't do this one of several "right ways".    The way I would do it would be to use a  couple of dual opamps...to split your signal and 'drive' both PCBs, and then to mix them back again.

Something like this:  http://www.runoffgroove.com/splitter-blend.html

Probably more than you wanted to get into , huh?   It would be a good project, and it is 'documented' so we can all follow if it gives you trouble.  There are other ways, using JFETs and stuff, but that would be 'homebrew'.   I think this one might do well for you....

[wray]

Thanks for this info. I have built the thunder chief off that site.  That is more involved than I had in mind. Ill give it a go.

[GibsonGM]

Technically, you could just build a buffer, any kind (transistor, op amp, JFET....) and use it to feed each circuit, probably thru 1k resistor on the input to each effect.   "U1A" in the splitter blend linked to would do the job; out to each thru a 1k resistor for each one.   Not fancy, but way better than just putting the inputs in parallel.

Then you can use a simple opamp mixer (net search...there are many many many plans for them out there....'summing amplifier') to sum their outputs.   If you used a dual opamp, you can use 1/2 for the input buffer, 1/2 for the mixer.      You just want to find a schematic for a mixer that uses a bias network and runs on 9V.  There are MANY around.    Alternatively, start looking up "guitar effects in parallel", and you may find a more elegant (but probably not as simple) idea.