guitar > Metalcore > NS-1 > Mesa input [clean channel] > Mesa effects send > SPX50D input > SPX L+R outputs > Mesa + 5150 effects returns [Left to one amp Right to the other]
OR
guitar > Metalcore > NS-1 > 5150 input > 5150 effects send > SPX50D input > SPX L+R outputs > Mesa + 5150 effects returns [Left to one amp Right to the other]
Thanx for the suggestions. ^
it worked,..no more feedback