effects loop noisy?

Hello- newbie here. Love my new ht 40. Sounds great! But, I like to run fx thru the loop, and am finding it to be noisy with a hum........ground loop? suggestions?

thanks

Wow. Crickets....................anyone? Bueller?

I thought my effects loop was noisy/humming. Sounded like a ground loop hum; however, I've found that the very same hum happens when effects loop is by-passed and I'm looking at other causes...about to take it to the shop under warranty...

It was a maddening search with combinations of pedals, cables, etc., and my hum happens intermittently, which adds to the difficulty when diagnosing.

Not really a helpful post on my part, if one is searching for a solution, perhaps, and I wanted to share my experience as I chase a problem that sounded like the one you're having.

If you can isolate the hum to the effects loop, you're a clear step ahead of me because I could not do that.

String

What effects are you running in the loop? Also there's a setting for the loop level, if you haven't tried changing that (button on the back of the amp) that may help troubleshoot it. I had a tuner that would hum if it didn't have its own power supply (battery or dedicated wall wart).

Quick Update:

Amp is back from the shop and... there was no hum while there.

So... I'm looking at the main power wiring as a likely culprit.

Also, the noise is a combination hum/scratchiness. Causes volume drops and other annoying sound issues.

As I've discovered, these amp noises can have multiple, if not many, possible points of origin.

I'll post back what I find.

I'm running my Graphic EQ, Chorus and Carbon Copy in the Loop.

String

You've probably already tried this but scratchiness/hum sounds like a bad cable in the loop or an effect that's behaving badly... have you tried different cables and just having one effect in there? If the shop couldn't get it to happen it could be what you're putting in the loop.