40uF/500VDC Sprague Atom TVA 1908 Capacitor, Length 2.375" x Diameter 1". These sturdy blue jacketed axial lead aluminum 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.