hello,
i´m using the mf delay (without expression pedal) since two days (max. 3 hours). i do not own the mf power supply, so i´m running it with a 9V battery.
everything worked fine, but as i tried to use it today, i couldn´t hear any feedback. the red led glows and the drive knob is still working, but there´s no echo.
i pushed all knobs in all directions, but nothing…
could it be a problem with the battery?
thanks for your answers…
cheers
I cannot believe what i’m reading now. 
EXACTLY the same thing happened to me 10 minutes ago !!!
i was using mf delay yesterday, and day before for a total of few hours, and i just plug it tonight again, and there is no feedback! Only dry signal when mix knob is in left position.
So i went here to try to find some support or whatever .
I also dont have mf power supply so i´m running it with a 9V battery.
Dont know what to do right now …
Did you check the battery?
Try a new one.
Stephen
HI All,
If you are using a battery and leaving your instrument cables plugged into your MF Delay when not in use, then you are draining the battery slowly - even if you aren’t using the pedal. You have to disconnect your instrument cables when not in use.
I don’t know about this particular case, but delays are usually really really hungry for power and will eat up a 9v battery really quickly.
Check your battery.
That was the case.
I changed the battery. Everything works as normal now.
Glad that this was reason at the end … 
Tnx for fast reply !
It should also be noted that this applies, as far as I know, to pedals from ALL manufacturers. You typically have to unplug the cable from the input jack when not in use or else you’ll be buying lots of batteries. Reverbs and delays are the worst offenders…