H90 and PBC squealing like a piggy!

[hecticwatermelon]

So, when I attempt to either insert the H90 "pre section" (input/output 1) in PBC loop 1 or in front of the PBC, it will start squealing on any gained amp setting. I have been through all the H90 line/instrument permutations and have also tried the ISO button on PBC. What on earth am I doing wrong?
FYI, the "post section" is just hooked into the UA studio interface.
Thanks,
John

 

[mcvittym]

Are your output levels on loop 1 set to guitar level or line level?

 

[rjmmusic]

Does it matter what preset the H90 is on? Does the H90 do it when the PBC loop is on but the pedal is bypassed?

 

[hecticwatermelon]

Does it matter what preset the H90 is on? Does the H90 do it when the PBC loop is on but the pedal is bypassed?

No, it doesn’t matter which preset H90 is on. The only thing that stops the squeal is turning the PBC loop off. Loop on and pedal bypassed still squeals.

 

[hecticwatermelon]

Are your output levels on loop 1 set to guitar level or line level?

Are you referring to the first “pre” loop of H90? If so, I have experimented with both and no combination solves issue.

 

[hecticwatermelon]

The only thing that is working as a temporary workaround is to insert the H90 pre section in the PBC Out 1-4/In 5-6. But I need to figure out how to put in either in front of PBC or in loop 1.

 

[rjmmusic]

That's really odd... what are you using to power the H90? Does turning off buffer #1 in the PBC change anything? And, what's in loops 2-4?

 

[hecticwatermelon]

H90 is powered with factory power supply. I will try moving it to another outlet. Turning on/off buffer had no effect. Loops 2-4 are gain pedals.

 

[fbiwaterman]

Did you guys resolve this? I had the exact same problem and got Dave Friedman to weigh in. the squeal is most definitely a ground loop and it seems that the H90 is very sensitive to them. Make sure everything on your amp and pedal board are tied to the same ground on the same electrical circuit. If you’re using wd or wdw you should get an isolation transformer. Also, don’t use too many buffers.

 

[hecticwatermelon]

Did you guys resolve this? I had the exact same problem and got Dave Friedman to weigh in. the squeal is most definitely a ground loop and it seems that the H90 is very sensitive to them. Make sure everything on your amp and pedal board are tied to the same ground on the same electrical circuit. If you’re using wd or wdw you should get an isolation transformer. Also, don’t use too many buffers.

Thanks for the reply—no, unresolved. I have only been feeding it the send from the DAW to keep it clean and simple. I may have one more ground loop thing to check, so will experiment further.
(BTW, I like your handle. I’m from the froggy side of the pond. )