VTL ST 150

Hello, is there a difference between the older ST-150 and the newer ST-150 with the silver-glass face in terms of specs/performance? I appreciate any help given.

Thank you,
Happy Holidays.
That would be a good question for VTL.
Yeah Rrog...but, problem is VTL doesn't answer inquiries...at least that's been my experience and that of anybody I've spoken to.
Which makes me wonder why anyone would purchase it... No matter how good it sounds.
I have heard about poor service from VTL over the years, however, I have always received excellent service from VTL.
They have always been helpful and responsive to me ...albeit I always introduced myself [at the time] as being "a current owner of...'one of their products'". I still like their amps though never tried their pre's. Just .02...
When I sent requests to VTL about their equipment, not only did they respond quickly and in detail, but also asked me to call them and discuss things further with them. So no problems at all in my experience, and just as good a response as any high-end manufacturer that I've contacted (though perhaps during the holidays, like most businesses, they may be a bit slower than usual).

As to the main question...while I'm not an expert by any means, there are certainly changes made to the design over the years (as an example, there's a ground near the tubes for easier biasing in newer ones), so the older ones will not be the same as the newer ones. Whether the difference involves sonic changes that are easily audible is a separate issue...I have no idea as I've only auditioned them recently, so have no experience with older ones.