RM4 parallel loop issue

[audiomidijace]

So the RM4 and the RT-250 are now both working and everything sounds clean.
However, when I hook up the parallel FX loop I get a really loud buzz. If I turn up the FX knob on the RM4 the buzz gets louder.
My guess is either a bad cable in the loop or a bad tube for the parallel loop.
The only things in the loop are a TC Nova Delay and a TC Nova Reverb. The catch is that the reverb is new and this is the first time I've used it. So it certainly "could" have issues. I also have an ISP Decemater, but the problem is the same with or without it.
I'll have to test the cables, the tube and the Reverb pedal, but I've not heard this kind of noise with the amp before.
Anyone ever had a similar issue?
Cheers,
Jace

 

[Graham Pearson]

First, "short circuit" the parallel loop by inserting a short jumper cable between the parallel out and the parallel in - if the buzz persists, the problem is within your RM4. Otherwise, the problem is with one of the external components in your loop.

 

[audiomidijace]

The good news is the loop is fine. Thank's for the suggestion. I don't know why I didn't think about that. It's likely just a bad cable. I'll have to find the culprit.