Newbie here - My SDII's FX loop hums pretty loud - any ideas?

Hi Guys - Denny from BlueFrets here. My SuperDrive II hums pretty loud when I put my Boss GT-6 through the loop. It gets louder when i turn up the master volume. It stops when I pull the RETURN out. All my cables are perfect as is the guitar(s) and the Boss. The amp is dead mint as well. Tubes perfect. It doesn't hum when I don't use the loop. any ideas on what it is, and if so, can it be quieted and how? Thanks all.

Denny
www.bluefrets.com

well don't use the boss pedal, boss pedals are notorious for having hum and being tone suckers they are cheaply made and not true bypass.Which means when they are disengaged they color your tone in a bad way taking away the chime and articulation.I gave up on multi effects processors a long time ago there a nice idea to have every effect at your beckoned call but i suggest getting individual effects for your effects make sure they are true bypass so stay away from all boss, digitech,line 6,mxr pretty much every pedal at guitar center,sam ash, musicians friend.Go to proguitarshop.com or pedalgeek.com,tonefactor.com, or tonetronix.com pedalpluseffectswarehouse.com they all deal in quality effects also check out artec pedals on ebay they are cheap but sound great and true bypass this should get you where u wanna be and take out that hum and hiss ok later man

There are a lot of reasons this might be happening.

The SD series effects loops are the best I have ever tried. I don't think that is the fault.

Mainly, it can happen for a number of reasons....

1) The most often problem I have run into was that the input effects power supply (from guitar to pedal to input) were on the same DC power supply as the effects loop effects.
Easy way to diagnose this, just plug your guitar straight into the amp, and have only effects loop pedals going. Is there still noise? If not, add the input effects but using a differnent power supply. Even then, if it buzzes, take the plug out and reverse it (i.e. plug it in the other way). If at all possible, use only input effects that are battery driven...don't use a power supply at all on them. Usually effects like reverb and delay use so much power they can't realisticly run on batteries, but whenever possible when trying to troubleshoot noise problems, use a (known good!) batter in the effect when you can...it takes a lot of the guesswork out of troubleshooting.

You see what I am getting at, isolate the problem...

2) Preamp tubes. I'm still not yet clear on the 12AXwb (V1) and 12X7wa (V2 and V3) reasoning..but IF you have other tube types in there, it might be the problem. I know for usre that V1 is super important..that one tube might make a lot of noise while the other (even if the same type) might not.