ARC's earlier tube amplifiers had a deserved reputation for tube failures and collateral damage that was fixed in later models.
There is a great post over on AK about a D115 that Dave G acquired as a sort of "kit" and built to ARC’s specs. As built under test it had some nasty habits. He carefully modded it to remove all of the nasty habits that would cause failures.Later model amps had all of his mods already incorporated or were redesigned to get rid of those problems.
The last few pages of the post covers all of that and why it was common for the tube amps of that era to fail. Seems there were a lot of "performance" mods that folks were doing that caused the same kind of failures that ARC had experienced. Once it was understood "why", steps were taken to fix the problem.
BillWojo
There is a great post over on AK about a D115 that Dave G acquired as a sort of "kit" and built to ARC’s specs. As built under test it had some nasty habits. He carefully modded it to remove all of the nasty habits that would cause failures.Later model amps had all of his mods already incorporated or were redesigned to get rid of those problems.
The last few pages of the post covers all of that and why it was common for the tube amps of that era to fail. Seems there were a lot of "performance" mods that folks were doing that caused the same kind of failures that ARC had experienced. Once it was understood "why", steps were taken to fix the problem.
BillWojo