buffer placement ..input or out

[vacuumdust]

I'm building a Stage Center Reverb that will sit on top of my amp...I want to add a discrete (jfet) buffer that's outside of the circuit that will be on all the time to help the signal after a fairly long run of cables.  Does it matter if it's right after the input jack of the SCR or right before the output jack??.  I've built an SCR before and with some minor mods it's a great unit.  I've never built a pedal with a buffer before so i'm just looking for some tips.  THANKS

[alanlan]

You mention that you have a long cable run.  How long is it and is it from your guitar or some other effect after your guitar?

If you do need a buffer for a long cable run, then ideally you want to place it at the driving end of the cable to overcome the extra cable capacitance, but if there is already something there with a buffer or low impedance output there then it's a bit pointless really.

Perhaps you could elaborate a little on your set up.

[R.G.]

I'm building a Stage Center Reverb that will sit on top of my amp...I want to add a discrete (jfet) buffer that's outside of the circuit that will be on all the time to help the signal after a fairly long run of cables.  Does it matter if it's right after the input jack of the SCR or right before the output jack??.  I've built an SCR before and with some minor mods it's a great unit.  I've never built a pedal with a buffer before so i'm just looking for some tips.  THANKS

The problem to be solved is that guitars are a high impedance source. They sound most clear if the buffer is inside the guitar. Failing that, just outside the guitar. Failing that, as close to the guitar (shortest cord) possible. Failing that, the amp or effect the signal hits first should have an input impedance of over 1M. Otherwise, you lose some amount of treble to the effect/amp and also to the cable capacitance. If you put the buffer after then end of a long cable, the treble is already being sucked out by the cable.

Some people LIKE this, calling it "brown", "mellow" or such. I've always thought I like getting all the treble I can into the amp and then removing it if I want.