@mixit - you could try some stuff I wrote and made available for free here: http://www.linuxdsp.co.uk these are jack client applications but you can patch them in to channels by making insert points. Installation instructions are included. Should (I hope) be very straight forward to install and use.
peder: - thank you for for the advice - will try that out.
linuxdsp: - Thank you for your response - the screen shots certainly look impressive - will return within a couple of weeks or so to tell about experiences.
peder: This is great! Your pointer - and the Ardour manual - helped me find out how to get the plugins working. The warnings about how incomplete and out-of-date the Ardour manual is, seem a little exaggerated - at least in this case.
So far, i have tried TAP reverb and echo - which provide a wealth of different settings. The installation was just a few clicks, and it worked right away. I never would have thought it was this easy.
Also, the ability to adjust parameters while the music plays, is very usefull.
linuxdsp: tried to download your plugin, but my version of linux is stripped down to nearly nothing, so it doesn’t even have an unzipper installed. i’m certain this could easily be remedied, but right now i feel i have enough things that need to be explored - i am more of a musician than a linux expert. Anyway, thank you for your input - maybe some day i will try it out.