Having problem with my tube amp feedback...

[panggun]

Hi all L6 users! First off, please understand my poor english... I'm korean(not north!).
First time I write here, and my problem is...

 

Everytime I make my preset without CAB/IR, and check RMS level of my chain.
I make my chain level around 25~26 rms, which is same with my pure signal guitar level(bypassed level).

 

And I only run my POD GO into real tube amp fx loop section, so that I can fully use my full signal chain including amp model

(of course CAB/IR off).

 

My effect chain is like this
GUITAR IN (NOT PADDED) > TS808 > TIMMY > AC30 (FULL AMP MODEL) > DIGITAL DELAY > PLATE REVERB > MAIN OUT(Instrument Level) > DIRECT INTO MARSHALL JVM410H TUBE AMP SERIAL/ PARALLEL FX RETURN(with -10dBV and mix level to wet 100%)

 

P.S.

Global EQ : 80Hz(low cut) and 5KHz(high cut) / don't use noisegate for unnatural tone loss / no external pedal

 

And this is my amp : Marshall JVM410H(master volume, resonance, presence all at noon, and 0% reverb) with 1960A CAB.

 

When I play with tube amp, I set master volume of my tube amp at 12 o'clock, and pod go volume knob at 12 o'clock.

But when I turn up pod go volume knob to around 2~3 o'clock, tube amp produces tooooooo much feedback that I can hardly controll for mute.

 

This really make me crazy. I always stand with my back toward the cabinet and far from Amp about 20 feet(5~6 meter),

but amp still make terrible feedback.

 

How can I escape from this problem? I really wanna have huge sound like stompbox only pedalboards that run into amp front input,

and also I don't wanna run my pod go into amp front!

I just wanna keep runing with tube amp return. And I cannot use PA system or FRFR speaker,

it's really annoying to use and my device isn't that good enough.

 

Do I have to make my chian RMS levels up or down?
or Do I have to use AMP OUT jack for connecting with tube amp?

PLEASE HELP ME... :(