Effect Loops

[dunner84]

I need some effect loops schooling. I have never used an effect loops before. I know what they do, but that is where my knowledge ends. I find myself needing to implement them in my builds. I have built several tube amps now, most from scratch, and after selling some have ended up with a collection I'm very happy with, and takes up just enough floorspace to keep my wife happy.

I need to be able to bypass my amps preamp, and plug another preamp into the power section. I also wouldn't mind trying my spring reverb unit in the loop.

First questions:

Active or Passive?
Series or Parallel?

The main thing I am trying to accomplish is running a separate preamp into the power section of my amps with little to know impact from the built in preamp.. The spring reverb is only a maybe...

Additionally, (for fun/curiosities sake? I would like to experiment with running the preamps of my amps into different power sections. Ie. tweed Princeton into blackface vibrolux power section.... is this simply just effect send from one amp to effect return of another?

What is the best way to implement this into my amps?

I appreciate any feedback

[sluckey]

Sounds like you just need a preamp out jack and a power amp in jack. When nothing is plugged into either jack the internal preamp is connected to the internal power amp. Plugging into the preamp out jack breaks the connection to the internal power amp and sends the internal preamp to an external amp, recorder, etc. Or plugging into the power amp jack breaks the connection from the internal preamp and allows an external preamp to be connected to this internal power amp. Pretty versatile for patching this and that into these and those. Or even inserting some FX pedals between the preamp and power amp. This is the basic. You may need to add active FX loop for more elaborate uses. Either way, you still gotta have two jacks. I suggest playing with this simple passive circuit for a while and moving up to an active circuit if/when the need arises.

Here's a working example...

     http://sluckeyamps.com/november/november.pdf