You can contact 4rockers at email This email address is being protected from spambots. You need JavaScript enabled to view it.

GSM: +420 734 152 981.


Street and postal address for amp mods & service:

U Elektry 650/2, 19300 Praha 9


Company address (postal address):

Norde Systems s.r.o.

Ke Katerinkam 1403/1

149 00 Praha 4

Czech Republic


4rockers is the registrated trademark owned by D.Samal, founder of 4rockers/Norde Systems s.r.o.

About 4rockers

4rockers company was founded by Slavek Samal (=D.Samal) in 2011 as a logical result of 25 years long history of development and repairs of guitar tube amps and other musical electronics. With a experience of guitar tube amps on stage, in the studio, during repairs he wants to reborn singing lead guitar sound under light of the current boring Chinese production.