HT5 Effects loop

[sizzlingbadger]

I think I see the volume issue now. The trailing signal from a time based effect is injected through the high gain channel when you switch from clean. If this is set fairly high then you will hear volume spike when you switch.

I have built my loop switch but now have issues when the ME-50 is front of amp and the loop (send, return) is effectively joined at the pedal to pass through I get high pitched feedback when using any distortion with high gain on the ME-50. The cables in the loop become microphonic and kicking the cable can set it off.

I'm thinking that moving the loop in the amp as per the volume fix may help. Does anyone know if this will effect the loop 4db/10db gain switch ?