We ship all units with the Jan Philips standard. I have shipped some with Tung-Sols if people specially requested or if I felt that they would prefer them. The unit was designed and voiced for the Jan Philips and we have a good stock of them.
I ship Tung-Sols with the mods typically, but I ship the preamps with the Jan Philips. Many have preferred the Jan Philips to the Tung-Sols and some have preferred the Tung Sols. They are both excellent and have different sonic signatures.
It is necessary to standardize things like tube choice when manufacturing, this is why we ship standard with the Jan's, for both SE and STD models.
Thanks,
Dan W.