On Mon, Nov 23, 2015 at 12:20 PM, jonetsu@teksavvy.com <jonetsu@teksavvy.com> wrote:

This might be not/so/easy to prouve although a number of screenshots
should. I have a guitar track that has a pre-fader send to another
track that adds delay. Then there is an audio drum track that records
what has/is played on a MIDI track that is in contact with a Korg
Microstation. There are no connections between the drum and guitar and
delay tracks, I have double verified in qjackctl. All of those tracks
go to the master bus. When the drum is played there is echo added to
it from the echo plugin of the other track. Taking out the echo plugin
results of having no more echo on the drum track. I will continue to
see what is going on. meanwhile, has anyone experience such a
behaviour in Ardour (4.4.0) ?

This can be caused by the capture setting of your audio interface (typically with builtin Intel HDA audio chipsets). However, if it only affects certain tracks rather than creating an echo of the whole mix, then it is likely some routing inside of Ardour.