Guitarix
1 Pedalboard using it

GxTubeDelay

Plugin screenshot
Delay

Control Default Min Max
gain -40.00 -40.00 16.00
feedback 0.00 0.00 10.00
delay 0.10 0.10 5000.00
level -60.00 -60.00 0.00
http://guitarix.sourceforge.net/plugins/gxtubedelay#tubedelay v.0:28.3-23