Hello!
I’m in the process of getting my recently acquired 2/90/2 retubed and looking up the differences between it and the late revision with the offset switches. Besides being able to change fan power and high/low power, are there any other differences besides the layout? I’ve heard rumors of the early models being even more similar to the 2150.
Thanks!
Welcome to the forum!
The basic topology of the past and present versions of the 2902 are essentially the same and are also mostly the same as the later, more refined revisions of the 2150. This makes sense as the 2902 was envisioned as a scaled down 2150.
Besides the Low Power mode on the current 2902, the old and current versions are functionally the same.
Where the early 2902 and current model really depart is the power transformer. It’s a toroid in the early version and an EI (rectangular type) in the current model.
Incidentally, the 2150 has a toroid power transformer, so in that respect your 2902 is right in between the 2150 and current 2902.
Where the 2150 really differs from the 2902 is in the size of the toroid and output transformers. That size difference (not to mention weight and cost) do make for a dramatic performance difference, especially in the low register.
Dave
Hi Dave!
Thanks for the reply. Very cool to see the design and “spirit” of the 2150 in the early 2/90/2 like that.
One further question. If I would at some point like a newer face plate for mine (mine is quite worn), is that something I could ask about or is the fact that it is an early model a limiting factor here?
Many thanks,
Chris
