Preamp sounds distorted

[TheFinisher]

Morning all,
Just plugged my Sondex preamp back into my second system and it sounds distorted , it was fine a few weeks ago , it has been in the garage and it’s getting cold here.
Also does anyone know what the switches could be for ? ( switches L & R on the circuit board)

 

[jan.didden]

It's not L R. Its H L. High Low. Most probably gain switching.

Jan

 

[TheFinisher]

Thanks Jan , I was kind of hoping they were gain switches as I can barely get it off zero in the volume.