Sprague Type TVA Atom Aluminium Tubular Axial Electrolytic Capacitors. Excellent sonics For Tube Guitar Amps and audiophile Hi-Fi. These sturdy, axial lead, aluminium electrolytic capacitors are preferred by most craftsmen for authentic vintage guitar amp and hi-fi restorations. Many of the best sounding classic guitar amps by Fender, Ampeg, Magnatone, Valco and many others used Sprague Atom series electrolytics.