04-04-2014, 04:21 PM
Yes they sound like wirewounds. It is probably lucky that you shut the power and they did not open, because if they did, the driver transistors would be blown also.
Its a bit of a tradeoff. The metal films will open but in doing so will blow the drivers and possibly previous stages, while protecting the supply.
By not blowing, the wirewounds protect the earlier driver stages but overload the supply, relying on the fuse for protection.
Actually, I would consider not changing the original resistors at all. Wirewounds are very tolerant of overloads, and if they did not actually melt or change value, they are as good as new.
Its a bit of a tradeoff. The metal films will open but in doing so will blow the drivers and possibly previous stages, while protecting the supply.
By not blowing, the wirewounds protect the earlier driver stages but overload the supply, relying on the fuse for protection.
Actually, I would consider not changing the original resistors at all. Wirewounds are very tolerant of overloads, and if they did not actually melt or change value, they are as good as new.