This is certainly a performance test associated with the Schiit Saga pre-amplifier utilizing two different pipes.
The machine and tubes that are extra on loan from sort user. Start to see the post on Schiit Saga in synchronous thread.<
The stock tube is a Russian made clone of 6NS7 which goes by label of 68HC as i mentioned in the review of saga. The additional pipe supplied is from Raytheon and ended up being built in United States Of America. You can view them side-by-side here: