Dean Markley K-150 gitarrförstärkare

Dean Markley K-150 guitar amplifier. This amplifier has controls for Drive, Volume, Treble, Middle, Bass and Reverb. It has inputs for Input, Footswitch, Phones, Line Out and Line In. Made in USA. Hello The amplifier worked perfectly four years ago but now that it hasn't been used for so long it crackles terribly, must be checked. Note it works and is not broken.