▁effect ". ▁A ▁variety ▁of ▁means ▁are ▁available ▁to ▁achieve ▁the ▁effect . ▁For ▁further ▁information ▁about ▁the ▁use ▁of ▁trem olo ▁in ▁music , ▁including ▁notation , ▁see ▁T rem olo . ▁ ▁History ▁The ▁first ▁self - standing ▁electronic ▁trem olo ▁effects ▁unit ▁may ▁have ▁been ▁produced ▁by ▁De Ar mond , ▁in ▁which ▁a ▁motor ▁sh akes ▁a ▁can ister ▁containing ▁a ▁" h ydro - fl uid " ▁( not ▁mer cur y ▁as ▁some ▁people ▁assume ), ▁oscill ating ▁the ▁can ister ▁containing ▁an ▁electro ly t ic ▁fluid ▁that ▁sends ▁the ▁signal ▁to ▁ground . ▁Ear liest ▁references ▁to ▁De Ar mond ' s ▁trem olo ▁unit ▁date ▁to ▁ 1 9 4 1 . ▁Starting ▁in ▁the ▁ 1 9 5 0 s ▁many ▁companies ▁began ▁incorpor ating ▁the ▁effect ▁into ▁guitar ▁ampl ifiers , ▁including ▁the ▁F ender ▁T rem ol ux ▁and ▁V ib rol ux : ▁Leo ▁F ender ▁marked ▁the ▁effect ▁on ▁F ender ▁ampl ifiers ▁as ▁" v ibr ato ", ▁convers ely ▁calling ▁the ▁v ibr ato ▁arm ▁on ▁his ▁F ender ▁Str at oc aster ▁a ▁trem olo ▁arm . ▁The ▁most ▁notable ▁early ▁ampl ifiers ▁with ▁built - in ▁trem olo ▁functions ▁were ▁the ▁ 1 9 6 1 ▁F ender ▁Pr inc eton ▁and ▁the ▁Gib son ▁Fal con . ▁In ▁such ▁ampl ifiers , ▁the ▁trem olo ▁circuit ▁was ▁relatively ▁simple , ▁using ▁as ▁little ▁as ▁a ▁dozen ▁components ▁and ▁one ▁half ▁of ▁a ▁t ube