Most manufacturers make no effort to protect their output transformers, but our transformers are considerable more expensive due to both size and exotic low loss core material and so we REALLY don't want to have to replace one. As a former equipment modifier, in my tweak years, I can attest that most old amplifiers have compromised output transformers due to sudden tube death. (A Dynaco ST70 with two good transformers is a very rare thing!)
But, that being said, I must admit that our six pack of metal film resistors have been overly protective (we could use one wirewound or power film instead but this hurts the sound and a fuse is even worse). We have upgraded this now to a ten pack of resistors and hopefully this solves the problem. If not we may consider just eliminating the protection altogether.
Ken Stevens
Convergent Audio Technology, Inc.