Agreed, it is a very good amp. I did not hear any warm sound but I did not use the original tube. I have a few sets of expensive 12AU7 tubes sitting in the closet. (The tubes are definitely over killed when you consider this $200 dollars)
the parts are of good quality when you consider the price.
There are toroidal transformer, two Elna audio grade 4700 uf cap, alps potential meter.
Of course, you may upgrade the output caps and the resistors of the...