Two Buffers In One Box

[mcasey1]

So I just put together a box with two in jacks, two out jacks, and a 9v jack and housed two AMZ Simple JFET Buffers on one perfboard.

http://www.muzique.com/schem/eagle.htm

I want a buffer at the beginning of the pedalboard and one at the end also and wanted to be able to plug in and out of one box for the entire board.  So the signal goes like this:

Guitar - Into buffer channel 1 - out of buffer channel 1 - into pedals - out of pedals - into buffer channel 2 - out of buffer channel 2 - amp.

Each buffer is a seperate channel, but I used the same ground for all jacks, 9v and both channels.  Is this bad?  Will it cause impedance or ground problems?  Is this a recipe for a ground loop???  Didnt notice any noise, but when I plug into channel 1 and out of channel two without putting a patch cable through channel 1 out and into channel 2 in I can still hear a little guitar when 9v is applied.  Is this normal?  The faint signal disappears when I remove power from buffer.

Also, I am assuming that I can hook both channels +9V to one DC jack and it will just draw more current than one channel, and that I dont need to mess with the voltage for powering two buffers from one jack?

Simple questions Im sure, but I just want to check.

Thanks,

Matt

[mcasey1]

cmon...

[Taylor]

All grounds in a pedalboard connect to each other at some point. There is no problem with connecting the grounds of 2 circuits together - this is what happens when you build multiple things in one box, or when you power things from a daisy chain supply. Technically, it's good practice to take the grounds from separate circuits and run them from the board to a single point, like the in jack for example, rather than just connecting the various ground points within each circuit willy nilly. But it doesn't matter that much, and you shouldn't be getting cross talk just from connected grounds.

The crosstalk is more likely either from an error in your build or from wires being near each other and bleeding into each other. You don't usually see this outside of high gain circuits, and/or stuff with LFOs.

It's fine to feed just 9v to the circuits, you don't need more voltage.