I have a JM4 which has been working just fine, but last week I noticed when I turned it on the volume was reduced considerably. I would say around 70% less.
I just assumed as the guitar or amp volume had been adjusted, or the master volume on the JM4, but no they were all OK. The master volume on the JM4 was around 15% (as standard) and the unit was loud. It now needs to be around 60-70% mark to get the same volume but it brings with it a large amount of unwanted noise.
I did not mess with the unit or change any settings etc, just turned it off. Turned it back on 2-3 hours later and noticed this instantly.
I have searched Google about this and it leads me to this site with similar questions, but I can't find a fix or answer as they seem to have been archived?
Any help appreciated.
P.S. I have tried all the obvious cables etc. If I take the guitar lead from the JM4 straight into my amp it's like back to the future volume in comparison.