Effects loop wont work ?????

[Valvehead]

This is kind of part 2 to my loop problem. ( today i moved the loop to the usual spot ) Im baffled as to why this amp does NOT want a loop in it !!

Orange Rocker 30 - Ive installed a basic passive loop in the amp. The amp has almost no volume and is very very distorted .

The loop is between the treble pot and the master volume---ive done this same loop on several amps and it has always worked.

What would cause this problem ?? Take a look at the picture --the tone stack is up at the top

[Jazz P Bass]

Copy this one?

[Valvehead]

Dont really want to add the tube and all the caps/res/ . Just wanted a simple passive like all the ones ive stuck in old Marshalls. I just dont understand why this isnt working. Im going insane.

[Enzo]

Disconnect your loop for now, tack some wires in or whatever it needs to put it back the way it was before. SO now it ought to work, right? MEASURE the signal level at the point you want to add the loop. That is what you have to work with.

Perhaps the signal at that point is something like 30v. That means a simple FX jack would be sending 30v of signal to the external device. That woulkd surely overdrive it and make it sound like crap. But then the output of your external device no doubt only puts put about a volt, not 30v, and so the amp, expecting to see 30v only sees 1v of signal so the volume is all but gone. That would explain both distorted sound and low levels. COuld this be your issue?

The extra tubes and resistors and stuff you don't want to add? On the example Jazz linked, the extra tube stages do two things. One is a major signal level reduction after the cathode follower to drive the FX send, and the other is a gain stage to make up for the low level of the returning signal.

[Valvehead]

ok--makes sense now. You were right , there is 22v ac of signal .

[Valvehead]

After looking at the amp tonight--there is absolutely no room for another tube. I guess this project is a bust

[The Dude]

How about something like THIS?

[defaced]

Check out the schematic I posted in this thread: http://music-electronics-forum.com/t33267/
MOSFET based SS loops are pretty simple creatures, which this being probably the simplest and most obvious incarnation of one. Adjust as needed, season to taste.

[Valvehead]

How about something like THIS?

that might work. it might barely fit in this amp