[TenTec] Ten-Tec 811A or 572B amplifiers?

[Ken Brown]

Looking at the Unofficial and official Ten-Tec web sites, I see only one 
amplifier by Ten-Tec that uses 811A tubes. This is the Centaur 411 which 
uses three 811As. Has Ten-Tec never made an amplifer that used two 811As 
or four 811As? How about 572Bs? Has Ten-Tec ever made an amplifier that 
used 572Bs? Can 572Bs be used in the Centaur 411?

DE N6KB