On ebay, I saw a Chippewa model KL-1 without power supply, pair 4-400A, 1960: http://www.ebay.com/itm/Rare-Vintage-Heathkit-Tube-Linear-Amplifier-Chippewa-KL-1-for-Ham-Radio-/281630963209?pt=LH_DefaultDomain_0&hash=item4192837609