FX Loop Schematic

Dax-The-Ax · Post by **Dax-The-Ax** » Mon Feb 21, 2005 2:39 pm

I Cannot read a schematic to save my life, can someone explain or draw which wires go to which lugs on this schematic.

Billy Batz · Post by **Billy Batz** » Mon Feb 21, 2005 2:58 pm

That didnt come out so clear. The top left writing says To board the top rigth says to treble pot wiper the lower left says return the lower left says send.

Dax · Post by **Dax** » Mon Feb 21, 2005 3:59 pm

Is That it!?? That seems so simple, is it a good FX Loop?

Billy Batz · Post by **Billy Batz** » Mon Feb 21, 2005 5:31 pm

Its passive. That means it doesnt buffer it doesnt do anything but allow you to run effects in the signal chain after the preamp and before the output section at your own risk. Its a simple FX loop that should be put on every amp because it doesnt hurt anything being there but at the same time if for some reason you wanted to use a loop you can use an external buffer before the FX. Without the buffer built into the amp with nothing plugged into the sockets its like theirs no loop there anyway. Other then the extra length and routing of the leads to and from the jacks.

Dax · Post by **Dax** » Mon Feb 21, 2005 11:49 pm

What????

Zoso · Post by **Zoso** » Tue Feb 22, 2005 12:02 am

Basically it is an insert between the preamp stage and the phase inverter/power amp section. It will take the signal from the preamp and send it out to whatever effects you have in the loop and then bring it back to the phase inverter. Essentially, your preamp section is feeding the effects, which in turn feed the phase inverter/power amp. If nothing is plugged into the jacks, then it is the same as a regular amp with no loop. So the effects come after the preamp gain and tone controls, but before the power amp.

Guest · Post by **Guest** » Tue Feb 22, 2005 12:07 am

So in a 2203, one wire would go to the middle treble pot lug and the other would go on the Master volume lug where the treble pot wire previously was?

Billy Batz · Post by **Billy Batz** » Tue Feb 22, 2005 6:58 am

If you wanted the master after the FX loop yes. I think its more common to have the master before the FX loop which would then have it with the Master wiper lug going to the send and the return going to the PI input cap on the board. Either way would work.

You can use an FX loop without a buffer. But you may run into problems with fidelity. You can always buy a small buffer for when you wnt to usee the FX loop. It doesnt hurt having a passive loop in the amp but its kind of counter-productive having a loop in an amp like a 1959 which has so much drive in the output section after the loop. In a 2203/4 its not a bad idea.

Dax · Post by **Dax** » Tue Feb 22, 2005 10:37 am

Thanks for the input.