Mr. Carlson reviews a Vacuum Tube Opamp module.

[BrianHG]

Here you go:

[vk6zgo]

Interestingly, similar modules were used to provide bistable multivibrators for digital dividers.
From memory, they used 12AT7s rather than the 12AX7s used in the Op-amp.

[cpuerror]

I wish he would get invited to be a guest on the amp hour.

[CatalinaWOW]

Maybe few of heard of it, but anyone who followed Bob Pease should know these well.  He cut his teeth on them and talked about them in several of his blurbs on analog design.