Buffer to mimic effects loop?

[manson]

A lot of TC Electronic and Lexicon rack gear seems to be designed to be used in effects loops. The TC stuff like the G-Major 2 has an input impedance of 21k ohm. My amp does not have an fx loop.. What would happen if I plugged in directly to the TC? Would it have a negative effect on the quality of my signal (load it down)? I have also made a couple of buffer boxes with a high input and low output imp. Would placing one of those between the guitar and the TC be a good substitute for an fx loop?

[anchovie]

Go for it. Using a buffer will not so much mimic an FX loop as provide a high-impedance load similar to an amp's input stage. The FX loop would be placed after the preamp in the signal path.

[liquids]

Yeah, rack effects expect a 'buffered' signal, in laymans terms.  I wish I had understood that far earlier, when I thought rack units needed something special to be compatible with guitar rigs.  Actually, I'm certain that  not all effects loops are ideal and/or low impedance out.  But if you have a buffer, you are good.

The strength of signal is not so much an issue...if you buffer your guitar signal (or your pedal chains signal) so long as you always run a consistent good buffer into the TC, it will be just fine, and the rack unit should be able to compensate for whatever signal level it wants, onboard.

Without the buffer, it is like sucking out all the gain and fidelity of your signal.  Also, it seems to add quite a bit of hum...but I have a buffer on a simple switch right before the rack unit, and when I turn it on...all is well.

I run my guitar into my pedals (some buffering, ideally) --> Volume pedal --> stand alone buffer --> lexicon rack unit (20k input impedance) --> amp.  Works wonderfully. 

[manson]

Right, that's what I thought. The rack unit expects a low impedance signal, and a buffer gives it just that.