Please see the attached link in case anyone wants to purchase enough tubes for your entire lifetime. http://www.ebay.com/itm/500-000-THOUSAND-NOS-NIB-TUBES-VALVES-VINTAGE-AUDIO-AMPLIFIER-STEREO-NEW-HI-FI-/302232800696?hash=item465e7a8db8:g:GmkAAOSwAANY5fYG 73, Victor, K2NBC