The only manufacturer I recall offering upgraded models was Ayre. Right now Denefrips is offering an upgrade circuit board for their Terminator dac, but other than that? I don't think it's a common practice, at least as far as I've seen. Unless you are using "update" to mean "repair"?
That's an issue with several companies, often due to to the lack of parts. I know Naim can service virtually everything they've ever made, which is kind of cool.
That's an issue with several companies, often due to to the lack of parts. I know Naim can service virtually everything they've ever made, which is kind of cool.