Tnclimber

That worked. I thought I had tried that as well. Thanks!

That is a good thought. I cannot find any documentation that indicates it is parallel. That is weird enough on its own. If it were I would think Orange would talk about it.

Maybe I will give them a call. I'm just wondering if my amp is defective or something.

Thanks for the reply.

The manual says "between the amps preamplifier section and output section." This means it is between the Gain control and output I think. Should this override the tube gain?

I think my rumble 800 head is the same and it bypasses everything but master volume.

Hello. I searched the forum on this but could not find the exact answer.

I have an Bass Terror 500 with a preamp in the effects loop. On other solid state amps when I do this everything on the amp itself is bypassed except master volume.

On the OBT 500 it seems like the Gain knob still works. I was under the impression that the effects loop would bypass the pre amp on the orange amplifier itself. 

I am new to tube or hybrid amps. Am I missing something? Should the Gain on the amp be bypassed in this situation?

Thanks!!