since lv2rack and zynjacku  are currently unmaintained  (btw, on my F20 install i'm getting runtime errors on both and do not start), i've started playing around Carla/Cadence packages by falkTX. I had to install indicator-cpufreq-selector and change the policy in polkit file and build many missing packages from source to get Cadence working, but now it seem to be ok. i had to update jack_capture to the lateset version as well, in order to obtain freewheeling rendering.

i'm wondering if there is any plan to include these packages in the spin by default

cheers

max