B1 XfORmer line stage

I watched the 2017 burning amp presentation from Nelson and he showed a very minimalistic xformer based line stage that uses the 2sk170/2sj74 pair as front followed by an autoformer from cinemag! I think its the cmoq-4 output transformer. Very interesting! Has anyone build it? I guess a B1 front end would also do the job with great specs.
Any thoughts? Maybe a schematic? Thanks!